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1 //! Shared theme loading + intent resolution for TOML-based theme files.
2 //!
3 //! Used by GoingsOn, Balanced Breakfast (Tauri apps), audiofiles (egui), and the
4 //! MNW web server. Themes are authored by **intent** ("human design"): colors are
5 //! declared by role (surface / content / action / status / line / category), not
6 //! by hue. This crate is the single place that resolves an authored theme into a
7 //! full set of intent tokens — including the derived interactive states
8 //! (hover/active/selection/row-stripe/contrast) that each app used to recompute
9 //! itself — and emits them as CSS variables or RGB tuples.
10 //!
11 //! Theme file shape:
12 //! ```text
13 //! [meta]
14 //! name = "Nord"
15 //! variant = "dark" # or "light"
16 //!
17 //! [surface] # container backgrounds by role/elevation
18 //! page = "#2e3440"; raised = "#3b4252"; sunken = "#434c5e"; overlay = "#3b4252"
19 //!
20 //! [content] # text/ink by emphasis
21 //! primary = "#d8dee9"; secondary = "#e5e9f0"; muted = "#616e88"
22 //!
23 //! [action] # interactive / brand color
24 //! primary = "#81a1c1"
25 //!
26 //! [status] # state semantics
27 //! danger = "#bf616a"; success = "#a3be8c"; warning = "#ebcb8b"; info = "#88c0d0"
28 //!
29 //! [line]
30 //! border = "#4c566a"
31 //!
32 //! [category] # distinct decorative colors for tags/badges/charts
33 //! one = "#bf616a"; two = "#a3be8c"; three = "#81a1c1"
34 //! four = "#ebcb8b"; five = "#b48ead"; six = "#88c0d0"
35 //! ```
36
37 // Color-space math: single-letter channel names (r/g/b/l/m/s) and the published
38 // high-precision OKLab/sRGB matrix constants are the domain vocabulary here.
39 #![allow(clippy::many_single_char_names, clippy::unreadable_literal)]
40
41 use serde::Serialize;
42 use std::collections::{BTreeMap, HashMap};
43 use std::path::{Path, PathBuf};
44
45 /// The color sections an authored theme may declare.
46 pub const COLOR_SECTIONS: &[&str] = &["surface", "content", "action", "status", "line", "category"];
47
48 /// Theme metadata parsed from the `[meta]` section.
49 #[derive(Debug, Clone, Serialize)]
50 #[serde(rename_all = "camelCase")]
51 pub struct ThemeMeta {
52 pub id: String,
53 pub name: String,
54 pub variant: String,
55 pub is_custom: bool,
56 }
57
58 /// A loaded theme: metadata plus the authored colors, flattened to dotted keys
59 /// (e.g. `"surface.page"`, `"status.danger"`, `"category.one"`).
60 #[derive(Debug, Serialize)]
61 #[serde(rename_all = "camelCase")]
62 pub struct ThemeColors {
63 pub meta: ThemeMeta,
64 pub colors: HashMap<String, String>,
65 }
66
67 // ============================================================================
68 // Color math — perceptual (OKLab) derivations + WCAG contrast.
69 //
70 // Interactive states (hover/active/selection/surfaces) are derived in OKLab so
71 // equal steps look equal across every theme's hues (Ottosson 2020; the modern
72 // CIELAB). Text-on-color is picked by the WCAG 2.x contrast ratio, not a naive
73 // luminance threshold, so the choice actually meets AA where achievable.
74 // This is the single source of truth shared by every product.
75 // ============================================================================
76
77 /// An sRGB color. Hex round-trips losslessly.
78 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
79 pub struct Rgb {
80 pub r: u8,
81 pub g: u8,
82 pub b: u8,
83 }
84
85 impl Rgb {
86 /// Parse `#rgb` or `#rrggbb` (case-insensitive). Returns `None` otherwise.
87 pub fn from_hex(s: &str) -> Option<Rgb> {
88 let h = s.strip_prefix('#')?;
89 let (r, g, b) = match h.len() {
90 6 => (
91 u8::from_str_radix(&h[0..2], 16).ok()?,
92 u8::from_str_radix(&h[2..4], 16).ok()?,
93 u8::from_str_radix(&h[4..6], 16).ok()?,
94 ),
95 3 => {
96 let d = |c: &str| u8::from_str_radix(c, 16).ok().map(|v| v * 17);
97 (d(&h[0..1])?, d(&h[1..2])?, d(&h[2..3])?)
98 }
99 _ => return None,
100 };
101 Some(Rgb { r, g, b })
102 }
103
104 /// Lowercase `#rrggbb`.
105 pub fn to_hex(self) -> String {
106 format!("#{:02x}{:02x}{:02x}", self.r, self.g, self.b)
107 }
108
109 pub fn tuple(self) -> (u8, u8, u8) {
110 (self.r, self.g, self.b)
111 }
112 }
113
114 /// A color in OKLab (perceptually uniform): `l` lightness in [0,1], `a`/`b` opponent axes.
115 #[derive(Clone, Copy, Debug)]
116 pub struct Oklab {
117 pub l: f32,
118 pub a: f32,
119 pub b: f32,
120 }
121
122 fn srgb_to_linear(c: u8) -> f32 {
123 let c = c as f32 / 255.0;
124 if c <= 0.04045 {
125 c / 12.92
126 } else {
127 ((c + 0.055) / 1.055).powf(2.4)
128 }
129 }
130
131 fn linear_to_srgb(c: f32) -> u8 {
132 let c = c.clamp(0.0, 1.0);
133 let v = if c <= 0.0031308 {
134 c * 12.92
135 } else {
136 1.055 * c.powf(1.0 / 2.4) - 0.055
137 };
138 (v * 255.0).round().clamp(0.0, 255.0) as u8
139 }
140
141 impl Rgb {
142 /// Convert to OKLab (Ottosson's sRGB matrices).
143 ///
144 /// The matrix coefficients are quoted at their published precision so they
145 /// can be diffed against the reference. `f32` rounds them at compile time;
146 /// truncating the literals would only make them harder to check.
147 #[allow(clippy::excessive_precision)]
148 pub fn to_oklab(self) -> Oklab {
149 let (r, g, b) = (
150 srgb_to_linear(self.r),
151 srgb_to_linear(self.g),
152 srgb_to_linear(self.b),
153 );
154 let l = 0.4122214708 * r + 0.5363325363 * g + 0.0514459929 * b;
155 let m = 0.2119034982 * r + 0.6806995451 * g + 0.1073969566 * b;
156 let s = 0.0883024619 * r + 0.2817188376 * g + 0.6299787005 * b;
157 let (l_, m_, s_) = (l.cbrt(), m.cbrt(), s.cbrt());
158 Oklab {
159 l: 0.2104542553 * l_ + 0.7936177850 * m_ - 0.0040720468 * s_,
160 a: 1.9779984951 * l_ - 2.4285922050 * m_ + 0.4505937099 * s_,
161 b: 0.0259040371 * l_ + 0.7827717662 * m_ - 0.8086757660 * s_,
162 }
163 }
164
165 /// Convert from OKLab back to the nearest in-gamut sRGB.
166 ///
167 /// Published precision, as in [`Rgb::to_oklab`].
168 #[allow(clippy::excessive_precision)]
169 pub fn from_oklab(c: Oklab) -> Rgb {
170 let l_ = c.l + 0.3963377774 * c.a + 0.2158037573 * c.b;
171 let m_ = c.l - 0.1055613458 * c.a - 0.0638541728 * c.b;
172 let s_ = c.l - 0.0894841775 * c.a - 1.2914855480 * c.b;
173 let (l, m, s) = (l_ * l_ * l_, m_ * m_ * m_, s_ * s_ * s_);
174 Rgb {
175 r: linear_to_srgb(4.0767416621 * l - 3.3077115913 * m + 0.2309699292 * s),
176 g: linear_to_srgb(-1.2684380046 * l + 2.6097574011 * m - 0.3413193965 * s),
177 b: linear_to_srgb(-0.0041960863 * l - 0.7034186147 * m + 1.7076147010 * s),
178 }
179 }
180 }
181
182 /// WCAG 2.x relative luminance of an sRGB color.
183 fn rel_luminance(c: Rgb) -> f32 {
184 0.2126 * srgb_to_linear(c.r) + 0.7152 * srgb_to_linear(c.g) + 0.0722 * srgb_to_linear(c.b)
185 }
186
187 /// WCAG 2.x contrast ratio between two colors, in [1, 21].
188 pub fn wcag_contrast(a: Rgb, b: Rgb) -> f32 {
189 let (la, lb) = (rel_luminance(a), rel_luminance(b));
190 let (hi, lo) = if la >= lb { (la, lb) } else { (lb, la) };
191 (hi + 0.05) / (lo + 0.05)
192 }
193
194 /// Pick black or white for legible text on `bg`, by the higher WCAG contrast
195 /// ratio (so the choice meets AA wherever the background allows it).
196 pub fn readable_on(bg: Rgb) -> Rgb {
197 let white = Rgb {
198 r: 255,
199 g: 255,
200 b: 255,
201 };
202 let black = Rgb { r: 0, g: 0, b: 0 };
203 if wcag_contrast(white, bg) >= wcag_contrast(black, bg) {
204 white
205 } else {
206 black
207 }
208 }
209
210 /// Shift OKLab lightness by `delta` (perceptually uniform). Positive lightens.
211 pub fn lighten(c: Rgb, delta: f32) -> Rgb {
212 let mut lab = c.to_oklab();
213 lab.l = (lab.l + delta).clamp(0.0, 1.0);
214 Rgb::from_oklab(lab)
215 }
216
217 /// Shift OKLab lightness down by `delta` (perceptually uniform).
218 pub fn darken(c: Rgb, delta: f32) -> Rgb {
219 lighten(c, -delta)
220 }
221
222 /// Interpolate between `a` and `b` by `t` in [0,1] in OKLab (perceptual blend).
223 pub fn mix(a: Rgb, b: Rgb, t: f32) -> Rgb {
224 let (x, y) = (a.to_oklab(), b.to_oklab());
225 Rgb::from_oklab(Oklab {
226 l: x.l + (y.l - x.l) * t,
227 a: x.a + (y.a - x.a) * t,
228 b: x.b + (y.b - x.b) * t,
229 })
230 }
231
232 // ============================================================================
233 // Low-color terminals
234 // ============================================================================
235
236 /// The 16 colors an ANSI terminal addresses by index, in the PC/VGA
237 /// arrangement the Linux console and most emulators start from.
238 ///
239 /// 0-7 are the normal colors and 8-15 the bright ones. Index 7 is a light gray
240 /// rather than white, which is the entry a themed surface usually lands on, and
241 /// index 15 is the true white.
242 ///
243 /// Emulators let the user repaint all sixteen, so this is the standard
244 /// arrangement rather than a promise about any one terminal. The Linux console
245 /// keeps it, which is the case that matters: a console app cannot fall back to
246 /// 24-bit color there.
247 pub const ANSI_16: [Rgb; 16] = [
248 Rgb {
249 r: 0x00,
250 g: 0x00,
251 b: 0x00,
252 },
253 Rgb {
254 r: 0xaa,
255 g: 0x00,
256 b: 0x00,
257 },
258 Rgb {
259 r: 0x00,
260 g: 0xaa,
261 b: 0x00,
262 },
263 Rgb {
264 r: 0xaa,
265 g: 0x55,
266 b: 0x00,
267 },
268 Rgb {
269 r: 0x00,
270 g: 0x00,
271 b: 0xaa,
272 },
273 Rgb {
274 r: 0xaa,
275 g: 0x00,
276 b: 0xaa,
277 },
278 Rgb {
279 r: 0x00,
280 g: 0xaa,
281 b: 0xaa,
282 },
283 Rgb {
284 r: 0xaa,
285 g: 0xaa,
286 b: 0xaa,
287 },
288 Rgb {
289 r: 0x55,
290 g: 0x55,
291 b: 0x55,
292 },
293 Rgb {
294 r: 0xff,
295 g: 0x55,
296 b: 0x55,
297 },
298 Rgb {
299 r: 0x55,
300 g: 0xff,
301 b: 0x55,
302 },
303 Rgb {
304 r: 0xff,
305 g: 0xff,
306 b: 0x55,
307 },
308 Rgb {
309 r: 0x55,
310 g: 0x55,
311 b: 0xff,
312 },
313 Rgb {
314 r: 0xff,
315 g: 0x55,
316 b: 0xff,
317 },
318 Rgb {
319 r: 0x55,
320 g: 0xff,
321 b: 0xff,
322 },
323 Rgb {
324 r: 0xff,
325 g: 0xff,
326 b: 0xff,
327 },
328 ];
329
330 /// The 256 colors an xterm-compatible terminal addresses by index, so that
331 /// entry `i` is what the terminal paints for `38;5;i`.
332 ///
333 /// Three regions, and they are not equally trustworthy. 0-15 are the [`ANSI_16`]
334 /// system colors, which every emulator lets the user repaint. 16-231 are a
335 /// 6x6x6 RGB cube and 232-255 a 24-step gray ramp, and those 240 are fixed.
336 ///
337 /// So a color whose whole job is to be told apart from another should quantize
338 /// against [`ANSI_240`] rather than against this table: a match landing in the
339 /// low sixteen is a match against a color the user may have moved.
340 pub const ANSI_256: [Rgb; 256] = build_ansi_256();
341
342 /// The fixed region of [`ANSI_256`]: the 6x6x6 cube and the gray ramp, without
343 /// the sixteen repaintable system colors.
344 ///
345 /// Quantizing against this returns an index into *this* slice; add
346 /// [`ANSI_240_OFFSET`] to get the index the terminal wants.
347 pub const ANSI_240: &[Rgb] = ANSI_256.split_at(16).1;
348
349 /// What to add to an [`ANSI_240`] index to get an [`ANSI_256`] one.
350 pub const ANSI_240_OFFSET: usize = 16;
351
352 /// The twelve chromatic ANSI slots, as the intents that paint them.
353 ///
354 /// Indexed 1-6 and 9-14. The hues do not depend on whether the theme is light
355 /// or dark, since red is the theme's danger tone either way, which is exactly
356 /// why the four achromatic slots are not in this table.
357 ///
358 /// Lifted from Alloy's `skelgen` on 2026-07-31, which had folded three
359 /// disagreeing hand-maintained copies into one and is the reason the
360 /// arrangement is trusted. It moved here so a program that paints its own
361 /// palette at runtime, rather than reading a generated config, resolves the
362 /// same slots. Slot 14 was the one the copies disagreed on and is
363 /// `category.six`, which both the Linux console table and the retired
364 /// `vtrgb.py` had.
365 const CHROMATIC: [(usize, &str); 12] = [
366 (1, "status.danger"),
367 (2, "status.success"),
368 (3, "status.warning"),
369 (4, "status.info"),
370 (5, "category.five"),
371 (6, "category.six"),
372 (9, "action.primary"), // bright red, the theme's warm accent
373 (10, "status.success"),
374 (11, "status.warning"),
375 (12, "status.info"),
376 (13, "category.five"),
377 (14, "category.six"),
378 ];
379
380 /// The four achromatic slots, 0, 7, 8 and 15, which invert with the theme.
381 ///
382 /// These are the slots a naive table gets wrong. ANSI 0 is "black" and 7 is
383 /// "white", but what a terminal wants there is *the darkest tone* and *the
384 /// lightest tone*, and which intent that is flips with the theme's polarity. A
385 /// light theme's darkest tone is its ink; a dark theme's is its deepest
386 /// surface. Pinning slot 0 to `content.primary` reads correctly on a light
387 /// theme and hands a dark one a pale cream as "black".
388 ///
389 /// Slot 7 is a surface and not a text tone, because it is what a program with
390 /// no way to name anything else draws its container on: a greeter's login card
391 /// is a light card on the darker field slot 0 paints.
392 ///
393 /// Anything that is not `dark`, including `high-contrast`, follows the light
394 /// anchors.
395 fn achromatic_slot(index: usize, variant: &str) -> Option<&'static str> {
396 let dark = variant == "dark";
397 Some(match (index, dark) {
398 (0, false) => "content.primary", // darkest text tone
399 (0, true) => "surface.sunken", // darkest surface
400 (7, false) => "surface.raised", // the login card
401 (7, true) => "content.secondary", // a readable light tone
402 (8, _) => "content.muted", // muted chrome, either way
403 (15, false) => "surface.overlay", // lightest surface
404 (15, true) => "content.primary", // lightest text tone
405 _ => return None,
406 })
407 }
408
409 /// The authored intent painting ANSI slot `index` under a theme of `variant`,
410 /// as a dotted key into [`ThemeColors::colors`].
411 ///
412 /// `None` for an index outside 0-15. Every slot in range resolves, so a caller
413 /// that has the intent can fill all sixteen.
414 ///
415 /// This is what makes a bare console, a terminal emulator and a generated
416 /// config agree on what red means. They disagreed for as long as each kept its
417 /// own table.
418 #[must_use]
419 pub fn ansi_intent(index: usize, variant: &str) -> Option<&'static str> {
420 achromatic_slot(index, variant).or_else(|| {
421 CHROMATIC
422 .iter()
423 .find(|(slot, _)| *slot == index)
424 .map(|(_, intent)| *intent)
425 })
426 }
427
428 const fn build_ansi_256() -> [Rgb; 256] {
429 let mut table = [Rgb { r: 0, g: 0, b: 0 }; 256];
430
431 let mut i = 0;
432 while i < 16 {
433 table[i] = ANSI_16[i];
434 i += 1;
435 }
436
437 // The cube's six levels are not evenly spaced. The step from black to the
438 // first is more than twice any later one, which is xterm's arrangement
439 // rather than a choice available here, and it is why the darkest tones a
440 // theme can reach on 256 colors come from the gray ramp instead.
441 const LEVELS: [u8; 6] = [0, 95, 135, 175, 215, 255];
442 let mut r = 0;
443 while r < 6 {
444 let mut g = 0;
445 while g < 6 {
446 let mut b = 0;
447 while b < 6 {
448 table[16 + 36 * r + 6 * g + b] = Rgb {
449 r: LEVELS[r],
450 g: LEVELS[g],
451 b: LEVELS[b],
452 };
453 b += 1;
454 }
455 g += 1;
456 }
457 r += 1;
458 }
459
460 // 8 to 238 in steps of 10. Neither end is black or white; both of those are
461 // in the cube, so the ramp is 24 steps of gray between them rather than 24
462 // steps of the whole range.
463 let mut k = 0;
464 while k < 24 {
465 let v = 8 + 10 * k as u8;
466 table[232 + k as usize] = Rgb { r: v, g: v, b: v };
467 k += 1;
468 }
469
470 table
471 }
472
473 /// The contrast ratio two colors must clear to read as separate areas.
474 ///
475 /// WCAG 2.x asks 3:1 of user interface components and graphics, which is what
476 /// a border, a rule, or a focus ring is. Text wants more, and a caller drawing
477 /// text can ask for more by checking [`wcag_contrast`] itself.
478 pub const DISTINCT: f32 = 3.0;
479
480 /// Perceptual distance between two colors, for choosing the closest of a set.
481 fn oklab_distance(a: Rgb, b: Rgb) -> f32 {
482 let (x, y) = (a.to_oklab(), b.to_oklab());
483 ((x.l - y.l).powi(2) + (x.a - y.a).powi(2) + (x.b - y.b).powi(2)).sqrt()
484 }
485
486 /// Index of the entry in `palette` that looks most like `c`.
487 ///
488 /// OKLab distance rather than distance in sRGB, for the same reason [`mix`]
489 /// interpolates there: sRGB's numbers are not spaced the way seeing is, so a
490 /// nearest match computed in it picks visibly wrong entries in the mid tones.
491 ///
492 /// # Panics
493 ///
494 /// If `palette` is empty.
495 pub fn quantize(c: Rgb, palette: &[Rgb]) -> usize {
496 assert!(!palette.is_empty(), "a palette needs at least one color");
497 let mut best = 0;
498 let mut best_distance = f32::INFINITY;
499 for (index, entry) in palette.iter().enumerate() {
500 let distance = oklab_distance(c, *entry);
501 if distance < best_distance {
502 best = index;
503 best_distance = distance;
504 }
505 }
506 best
507 }
508
509 /// Index of the entry in `palette` closest to `fg` that still reads against
510 /// `bg`.
511 ///
512 /// [`quantize`] answers about one color at a time, and two colors that differ
513 /// can quantize to the same entry: a themed page and a border drawn on it are
514 /// often a few steps apart in a 24-bit theme and land together on a 16-color
515 /// terminal, leaving one flat area where there was a frame. Alloy's console
516 /// showed exactly this, and it is not a contrived pairing: a light page and the
517 /// mid-tone border derived from it both land on index 7.
518 ///
519 /// So the background is quantized first, because what the border must be
520 /// distinguished from is the entry the terminal will actually paint, not the
521 /// color the theme asked for. Then the nearest entry to `fg` clearing
522 /// [`DISTINCT`] against it wins. When nothing clears it, the entry that gets
523 /// furthest does: at that point the palette cannot honor the design, and the
524 /// most legible approximation beats the closest invisible one.
525 ///
526 /// Only for colors whose whole job is to be told apart from their background.
527 /// Applied to every token it would push a deliberately quiet one until it
528 /// shouted.
529 ///
530 /// # Panics
531 ///
532 /// If `palette` is empty.
533 pub fn quantize_against(fg: Rgb, bg: Rgb, palette: &[Rgb]) -> usize {
534 assert!(!palette.is_empty(), "a palette needs at least one color");
535 let shown = palette[quantize(bg, palette)];
536
537 let mut order: Vec<usize> = (0..palette.len()).collect();
538 order.sort_by(|a, b| {
539 oklab_distance(fg, palette[*a]).total_cmp(&oklab_distance(fg, palette[*b]))
540 });
541
542 order
543 .iter()
544 .copied()
545 .find(|index| wcag_contrast(palette[*index], shown) >= DISTINCT)
546 .unwrap_or_else(|| {
547 order
548 .iter()
549 .copied()
550 .max_by(|a, b| {
551 wcag_contrast(palette[*a], shown).total_cmp(&wcag_contrast(palette[*b], shown))
552 })
553 .expect("the palette is not empty")
554 })
555 }
556
557 // ============================================================================
558 // Intent resolution
559 // ============================================================================
560
561 /// Authored base intents: (TOML dotted source key, canonical token key).
562 /// These are read straight from the theme; the token key is the CSS-var stem
563 /// (`--{token}`) and the `rgb()` lookup key.
564 pub const BASE_INTENTS: &[(&str, &str)] = &[
565 ("surface.page", "surface-page"),
566 ("surface.raised", "surface-raised"),
567 ("surface.sunken", "surface-sunken"),
568 ("surface.overlay", "surface-overlay"),
569 ("content.primary", "content"),
570 ("content.secondary", "content-secondary"),
571 ("content.muted", "content-muted"),
572 ("action.primary", "action"),
573 ("status.danger", "danger"),
574 ("status.success", "success"),
575 ("status.warning", "warning"),
576 ("status.info", "info"),
577 ("line.border", "border"),
578 ("category.one", "category-one"),
579 ("category.two", "category-two"),
580 ("category.three", "category-three"),
581 ("category.four", "category-four"),
582 ("category.five", "category-five"),
583 ("category.six", "category-six"),
584 ];
585
586 /// A fully resolved intent layer: every token key → concrete `#rrggbb`.
587 /// Includes both authored base intents and the computed derived intents.
588 #[derive(Debug, Clone, Serialize)]
589 #[serde(rename_all = "camelCase")]
590 pub struct SemanticTokens {
591 pub meta: ThemeMeta,
592 /// token-key → resolved hex. Stable, deterministic ordering.
593 pub intents: BTreeMap<String, String>,
594 }
595
596 impl SemanticTokens {
597 /// Resolved hex for a token key, if present.
598 pub fn hex(&self, key: &str) -> Option<&str> {
599 self.intents.get(key).map(String::as_str)
600 }
601
602 /// Resolved RGB tuple for a token key (for egui / native consumers).
603 ///
604 /// `None` for a translucent token. Two intents are emitted as `rgba(...)`
605 /// rather than hex, `overlay` and `elevation`, and dropping the alpha would
606 /// hand a native consumer an opaque near-black where it asked for a scrim.
607 /// Those want [`rgba`](Self::rgba).
608 pub fn rgb(&self, key: &str) -> Option<(u8, u8, u8)> {
609 self.intents
610 .get(key)
611 .and_then(|h| Rgb::from_hex(h))
612 .map(Rgb::tuple)
613 }
614
615 /// Resolved RGBA tuple for a token key, alpha as 0-255.
616 ///
617 /// Reads both spellings, so a caller that does not care whether an intent
618 /// happens to be translucent can use this for everything: an opaque token
619 /// comes back at 255.
620 ///
621 /// It exists because a CSS consumer can take `rgba(...)` as a string
622 /// straight out of [`hex`](Self::hex) and a native one cannot. Without it
623 /// the two translucent intents are reachable from a stylesheet and from
624 /// nowhere else, which is the coupling deriving in the crate was meant to
625 /// avoid.
626 pub fn rgba(&self, key: &str) -> Option<(u8, u8, u8, u8)> {
627 let value = self.intents.get(key)?;
628 if let Some(rgb) = Rgb::from_hex(value) {
629 let (r, g, b) = rgb.tuple();
630 return Some((r, g, b, 255));
631 }
632 let inner = value.strip_prefix("rgba(")?.strip_suffix(')')?;
633 let mut parts = inner.split(',').map(str::trim);
634 let r = parts.next()?.parse().ok()?;
635 let g = parts.next()?.parse().ok()?;
636 let b = parts.next()?.parse().ok()?;
637 let alpha: f32 = parts.next()?.parse().ok()?;
638 if parts.next().is_some() || !(0.0..=1.0).contains(&alpha) {
639 return None;
640 }
641 Some((r, g, b, (alpha * 255.0).round() as u8))
642 }
643 }
644
645 /// Resolve an authored theme into the full intent token set.
646 ///
647 /// 1. Copy each present base intent from the authored colors.
648 /// 2. Compute the derived interactive states from the base intents, using the
649 /// same math the apps used to apply individually (so output is identical).
650 ///
651 /// Each derived token is emitted only when its source intents exist, mirroring
652 /// the skip-missing behavior of the rest of the crate.
653 pub fn resolve(theme: &ThemeColors) -> SemanticTokens {
654 let mut intents: BTreeMap<String, String> = BTreeMap::new();
655
656 // 1. Base intents (authored). Copy only values that parse as a hex color and
657 // re-emit them in canonical `#rrggbb` form, so an authored value can never
658 // carry arbitrary bytes into the emitted CSS (the resolved tokens are inlined
659 // raw into a `<style>` block by the web server). A malformed value is skipped,
660 // mirroring the skip-missing behavior for absent intents.
661 for (src, token) in BASE_INTENTS {
662 if let Some(rgb) = theme.colors.get(*src).and_then(|v| Rgb::from_hex(v)) {
663 intents.insert((*token).to_string(), rgb.to_hex());
664 }
665 }
666
667 // Helper: parse an already-resolved token to Rgb.
668 let get = |m: &BTreeMap<String, String>, k: &str| m.get(k).and_then(|h| Rgb::from_hex(h));
669
670 // 2. Derived intents — perceptual (OKLab) steps + WCAG-picked text.
671 // Lightness deltas are in OKLab L units; mix ratios interpolate in OKLab.
672 let mut derived: Vec<(String, Rgb)> = Vec::new();
673 if let Some(action) = get(&intents, "action") {
674 derived.push(("action-hover".into(), lighten(action, 0.05)));
675 derived.push(("content-on-action".into(), readable_on(action)));
676 derived.push(("focus-ring".into(), action));
677 }
678 if let Some(page) = get(&intents, "surface-page") {
679 // Modal scrim: a near-black tone carrying a faint hint of the theme's
680 // hue, at 50% alpha. Anchored very dark (OKLab L=0.08) so it dims the
681 // page on light *and* dark themes. Emitted as rgba (not a flat hex), so
682 // it is inserted directly rather than through the hex loop below.
683 let mut o = page.to_oklab();
684 o.l = 0.08;
685 let s = Rgb::from_oklab(o);
686 intents.insert(
687 "overlay".into(),
688 format!("rgba({}, {}, {}, 0.5)", s.r, s.g, s.b),
689 );
690
691 // What a surface that FLOATS OVER the page is cast onto it with.
692 //
693 // The one intent here about a surface's relationship to the page rather
694 // than about the surface itself, which is why it is derived from `page`
695 // and not from `surface-raised`. A shadow is not the thing, it is the
696 // absence of light on what is behind the thing.
697 //
698 // SCOPE, and it is the whole point of this intent existing rather than
699 // a general "shadow": a surface that overlays the page takes this, a
700 // surface IN the page takes a bevel. Menus, toasts, popovers and
701 // dropdowns overlay. A card, a plate and a framed image do not, and
702 // reaching for this on one of those is how a pre-Platinum look survives
703 // a conversion wearing a token's name. `.raised` is the answer there.
704 //
705 // Same anchor as the scrim above and for the same reason: a tone read
706 // off the theme's hue but pinned very dark, so it reads as absence of
707 // light on a light theme and on a dark one alike. A shadow tinted to a
708 // dark theme's own lightness would not be a shadow.
709 //
710 // The alpha is the only number here that is a look decision rather than
711 // a derivation. 0.18 sits between the two literal scales it replaces:
712 // the MNW server's --shadow-2 (0.10) reads as nothing under a menu, and
713 // its --shadow-3 (0.15) was measured invisible at plate size. Geometry
714 // stays with the consumer, the way bevel thickness does.
715 intents.insert(
716 "elevation".into(),
717 format!("rgba({}, {}, {}, 0.18)", s.r, s.g, s.b),
718 );
719 }
720 if let Some(raised) = get(&intents, "surface-raised") {
721 // The two edges of a bevel: a raised control is lit from the top left,
722 // so its top and left edges take `bevel-light` and its bottom and right
723 // edges `bevel-dark`. Inverting the pair gives a pressed state and an
724 // inset well, which is what makes the idiom cheap for a consumer.
725 //
726 // Derived here rather than composed per-app because the two webviews
727 // could do it in `color-mix()` and audiofiles, which is egui, could not.
728 // Geometry (thickness, radius, which side gets which) stays app-side.
729 //
730 // The deltas are asymmetric because the eye is: an equal step down reads
731 // as a smaller change than the same step up, so the shadow is cut deeper
732 // than the highlight is raised.
733 //
734 // A face already at the top of the ramp cannot hold a highlight — the
735 // lightening clamps and the control bevels on two sides without ever
736 // resolving as lit. That is a property of the theme, not of this
737 // derivation; `bevel_edges_are_distinct_from_their_face` names the
738 // shipped themes it currently bites.
739 derived.push(("bevel-light".into(), lighten(raised, 0.14)));
740 derived.push(("bevel-dark".into(), darken(raised, 0.18)));
741
742 // An inset well: the content surface inside a raised container, so a
743 // list reads as content in a container rather than as bands on a panel.
744 // `surface-sunken` cannot serve, because a theme is free to author it
745 // darker than raised (goingson does) and a well has to go the other way.
746 //
747 // Which way is "the other way" depends on the theme, and this is the one
748 // derivation here that inverts. A well is lighter than its face on a
749 // light theme and darker on a dark one, where the bevel pair sidesteps
750 // the question by emitting both directions at once.
751 //
752 // Read the direction off `content` rather than off `Variant`. A theme
753 // whose text is dark is a theme whose surfaces are light, whatever its
754 // `variant` field claims, so this resolves correctly even when that
755 // field is wrong and it keeps the branch on measured color rather than
756 // on metadata.
757 //
758 // Deltas are asymmetric for the same reason the bevel's are, and smaller
759 // than the bevel's because a well is an area rather than an edge. The
760 // step up is the specimen's, measured: #D9DDF4 to #F3F5FD is 0.069.
761 //
762 // A face at the top of its ramp cannot hold a lighter well, the same
763 // clamp `bevel-light` hits; `well_is_visible_against_its_face` names the
764 // shipped themes where it bites.
765 if let Some(content) = get(&intents, "content") {
766 let content_is_darker = content.to_oklab().l < raised.to_oklab().l;
767 let well = if content_is_darker {
768 lighten(raised, 0.07)
769 } else {
770 darken(raised, 0.09)
771 };
772 derived.push(("surface-well".into(), well));
773 }
774 }
775 if let Some(sunken) = get(&intents, "surface-sunken") {
776 derived.push(("hover-surface".into(), sunken));
777 }
778 if let Some(border) = get(&intents, "border") {
779 derived.push(("border-strong".into(), darken(border, 0.05)));
780 }
781
782 for (token, rgb) in derived {
783 intents.insert(token, rgb.to_hex());
784 }
785
786 SemanticTokens {
787 meta: theme.meta.clone(),
788 intents,
789 }
790 }
791
792 /// Emit the resolved intent layer as CSS declarations (no selector), one
793 /// ` --token: #hex;` line each, in deterministic (BTreeMap) order.
794 pub fn intent_css_declarations(tokens: &SemanticTokens) -> String {
795 let mut out = String::new();
796 for (token, hex) in &tokens.intents {
797 out.push_str(" --");
798 out.push_str(token);
799 out.push_str(": ");
800 out.push_str(hex);
801 out.push_str(";\n");
802 }
803 out
804 }
805
806 /// Emit the resolved intent layer as a `:root { … }` block — the single TOML →
807 /// CSS mapping every web surface injects.
808 pub fn intent_css_vars(tokens: &SemanticTokens) -> String {
809 format!(":root {{\n{}}}\n", intent_css_declarations(tokens))
810 }
811
812 // ============================================================================
813 // Loading / parsing
814 // ============================================================================
815
816 /// Validate a theme ID contains only safe characters (alphanumeric, hyphens, underscores).
817 pub fn validate_theme_id(id: &str) -> Result<(), String> {
818 if !id
819 .chars()
820 .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
821 {
822 return Err(format!("Invalid theme ID: {id}"));
823 }
824 Ok(())
825 }
826
827 /// Parse the `[meta]` section into `ThemeMeta`.
828 ///
829 /// Falls back to the file ID as the name and `"dark"` as the variant.
830 pub fn parse_meta(id: &str, table: &toml::Table, is_custom: bool) -> ThemeMeta {
831 let meta = table.get("meta").and_then(|m| m.as_table());
832 let name = meta
833 .and_then(|m| m.get("name"))
834 .and_then(|v| v.as_str())
835 .unwrap_or(id)
836 .to_string();
837 let variant = meta
838 .and_then(|m| m.get("variant"))
839 .and_then(|v| v.as_str())
840 .unwrap_or("dark")
841 .to_string();
842
843 ThemeMeta {
844 id: id.to_string(),
845 name,
846 variant,
847 is_custom,
848 }
849 }
850
851 // ============================================================================
852 // Choosing a theme.
853 //
854 // The file half of this crate was always shared; the *selection* half was not,
855 // and four apps re-rolled it four ways. GoingsOn stores a "system" sentinel in
856 // localStorage, Balanced Breakfast treats an absent value as follow-the-system
857 // and hardcodes two theme ids as its light/dark pair, audiofiles keeps the id
858 // in a synced SQLite table, and the Alloy console parses COLORFGBG. They also
859 // disagreed about what a variant string means: this crate defaults a missing
860 // one to "dark" while alloy_tui parsed an unrecognized one as light.
861 //
862 // What cannot be shared is the store — localStorage, a synced config table and
863 // a TOML file are genuinely different places. What can be shared, and is here,
864 // is the *meaning*: one vocabulary for variants, one encoding for "what did the
865 // user choose", and one rule for turning that into an id that exists.
866 // ============================================================================
867
868 /// A theme's kind, as declared by `meta.variant`.
869 ///
870 /// Three, not two: one shipped theme is `high-contrast`, and an app that
871 /// matched on light-or-dark alone would quietly file it under the wrong one.
872 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize)]
873 #[serde(rename_all = "kebab-case")]
874 pub enum Variant {
875 Light,
876 Dark,
877 HighContrast,
878 }
879
880 impl Variant {
881 /// The spelling used in a theme file and in [`ThemeMeta::variant`].
882 #[must_use]
883 pub const fn as_str(self) -> &'static str {
884 match self {
885 Variant::Light => "light",
886 Variant::Dark => "dark",
887 Variant::HighContrast => "high-contrast",
888 }
889 }
890
891 /// Read a variant string, or `None` if it names none of them.
892 #[must_use]
893 pub fn parse(raw: &str) -> Option<Self> {
894 match raw {
895 "light" => Some(Variant::Light),
896 "dark" => Some(Variant::Dark),
897 "high-contrast" => Some(Variant::HighContrast),
898 _ => None,
899 }
900 }
901 }
902
903 impl std::fmt::Display for Variant {
904 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
905 f.write_str(self.as_str())
906 }
907 }
908
909 /// Anything unrecognized reads as dark, which is what [`parse_meta`] already
910 /// does with a missing one. Consumers that guessed light for an unknown string
911 /// were disagreeing with the crate that produced it.
912 impl From<&str> for Variant {
913 fn from(raw: &str) -> Self {
914 Variant::parse(raw).unwrap_or(Variant::Dark)
915 }
916 }
917
918 impl ThemeMeta {
919 /// This theme's variant as a value rather than a string.
920 #[must_use]
921 pub fn kind(&self) -> Variant {
922 Variant::from(self.variant.as_str())
923 }
924 }
925
926 /// The spelling of "follow whatever the system is doing", in every store.
927 pub const FOLLOW: &str = "system";
928
929 /// What the user chose, as opposed to what is being rendered.
930 ///
931 /// The distinction is the whole point: `Follow` is a standing instruction that
932 /// resolves differently as the ambient mode changes, and a `Fixed` id is an
933 /// answer that does not. An app that stored only the rendered id could not tell
934 /// the two apart the next time the system flipped to dark.
935 #[derive(Debug, Clone, PartialEq, Eq, Default)]
936 pub enum ThemeSelection {
937 /// Track the ambient light/dark mode.
938 #[default]
939 Follow,
940 /// Always this theme.
941 Fixed(String),
942 }
943
944 impl ThemeSelection {
945 /// Read a stored selection. An empty or absent value is [`Follow`], which
946 /// is what an app with nothing saved yet should do.
947 ///
948 /// [`Follow`]: ThemeSelection::Follow
949 #[must_use]
950 pub fn parse(raw: Option<&str>) -> Self {
951 match raw.map(str::trim) {
952 None | Some("" | FOLLOW) => ThemeSelection::Follow,
953 Some(id) => ThemeSelection::Fixed(id.to_string()),
954 }
955 }
956
957 /// The string to persist, whatever the store is.
958 #[must_use]
959 pub fn as_str(&self) -> &str {
960 match self {
961 ThemeSelection::Follow => FOLLOW,
962 ThemeSelection::Fixed(id) => id,
963 }
964 }
965
966 /// Turn a selection into a theme id that exists.
967 ///
968 /// `ambient` is the light/dark mode the app learned however it can: a
969 /// `prefers-color-scheme` media query, an OS appearance API, `COLORFGBG`
970 /// from a terminal. `available` is what [`list_themes_from_dirs`] found.
971 ///
972 /// A `Fixed` id that is no longer on disk falls through to the same path as
973 /// `Follow` rather than being returned anyway. Themes are deletable in
974 /// three of the four apps, and handing back an id that will fail to load
975 /// only moves the error somewhere less helpful.
976 ///
977 /// The fallback chain is: the app's own default for the ambient mode if it
978 /// is installed, then any installed theme of that variant, then the app's
979 /// default regardless. The last step means this always returns something,
980 /// and an app with no theme directory at all gets the id it ships with and
981 /// the load error it would have had anyway.
982 #[must_use]
983 pub fn resolve(
984 &self,
985 ambient: Variant,
986 defaults: &ThemeDefaults,
987 available: &[ThemeMeta],
988 ) -> String {
989 let installed = |id: &str| available.iter().any(|meta| meta.id == id);
990
991 if let ThemeSelection::Fixed(id) = self
992 && installed(id)
993 {
994 return id.clone();
995 }
996
997 let preferred = defaults.for_variant(ambient);
998 if installed(preferred) {
999 return preferred.to_string();
1000 }
1001 available
1002 .iter()
1003 .find(|meta| meta.kind() == ambient)
1004 .map_or_else(|| preferred.to_string(), |meta| meta.id.clone())
1005 }
1006 }
1007
1008 impl std::fmt::Display for ThemeSelection {
1009 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1010 f.write_str(self.as_str())
1011 }
1012 }
1013
1014 /// The themes an app falls back to, one per ambient mode.
1015 ///
1016 /// App-specific on purpose: which theme is "the app's own" is the app's
1017 /// identity, not this crate's business. What is shared is everything around it.
1018 #[derive(Debug, Clone)]
1019 pub struct ThemeDefaults {
1020 light: String,
1021 dark: String,
1022 high_contrast: Option<String>,
1023 }
1024
1025 impl ThemeDefaults {
1026 pub fn new(light: impl Into<String>, dark: impl Into<String>) -> Self {
1027 Self {
1028 light: light.into(),
1029 dark: dark.into(),
1030 high_contrast: None,
1031 }
1032 }
1033
1034 /// Name a theme for a high-contrast ambient mode. Without one, that mode
1035 /// falls back to the dark default, which is the safer of the two to read.
1036 #[must_use]
1037 pub fn high_contrast(mut self, id: impl Into<String>) -> Self {
1038 self.high_contrast = Some(id.into());
1039 self
1040 }
1041
1042 #[must_use]
1043 pub fn for_variant(&self, variant: Variant) -> &str {
1044 match variant {
1045 Variant::Light => &self.light,
1046 Variant::Dark => &self.dark,
1047 Variant::HighContrast => self.high_contrast.as_ref().unwrap_or(&self.dark),
1048 }
1049 }
1050 }
1051
1052 // ============================================================================
1053 // Where themes are looked for.
1054 //
1055 // Four apps built this vector by hand, two of them byte-for-byte identically,
1056 // and one of them built it backwards: the Alloy console pushed the user's own
1057 // directory first, under a comment saying "highest precedence first", when both
1058 // consumers of the vector resolve *last* wins. A user's custom theme lost to
1059 // the packaged one of the same id.
1060 //
1061 // Hence a builder that names the tiers rather than a function taking a vector.
1062 // The precedence is stated once, here, and a caller cannot express it backwards
1063 // because the order is not theirs to choose.
1064 // ============================================================================
1065
1066 /// Builds the search path [`load_theme`] and [`list_themes_from_dirs`] take.
1067 ///
1068 /// Tiers are added in whatever order is convenient and always end up in
1069 /// precedence order: the user's own themes win, then whatever the system
1070 /// ships, then whatever the app bundles.
1071 ///
1072 /// A directory that does not exist is dropped rather than carried, so callers
1073 /// can offer every tier they might have without checking each one.
1074 #[derive(Debug, Default, Clone)]
1075 pub struct ThemeDirs {
1076 bundled: Vec<PathBuf>,
1077 system: Vec<PathBuf>,
1078 custom: Option<PathBuf>,
1079 }
1080
1081 impl ThemeDirs {
1082 #[must_use]
1083 pub fn new() -> Self {
1084 Self::default()
1085 }
1086
1087 /// Themes the app ships with. Lowest precedence.
1088 ///
1089 /// Takes more than one because a Tauri app has two: the bundled resource
1090 /// directory in production, and the tree `build.rs` materialized for a
1091 /// `cargo run` that has no resource directory at all.
1092 #[must_use]
1093 pub fn bundled(mut self, dir: Option<PathBuf>) -> Self {
1094 self.bundled.extend(dir);
1095 self
1096 }
1097
1098 /// Themes the machine ships, from an image or a package. Overrides bundled.
1099 #[must_use]
1100 pub fn system(mut self, dir: Option<PathBuf>) -> Self {
1101 self.system.extend(dir);
1102 self
1103 }
1104
1105 /// The user's own themes. Highest precedence, and the only tier flagged
1106 /// custom, which is what makes them exportable and deletable.
1107 #[must_use]
1108 pub fn custom(mut self, dir: Option<PathBuf>) -> Self {
1109 self.custom = dir;
1110 self
1111 }
1112
1113 /// The search path, lowest precedence first.
1114 #[must_use]
1115 pub fn build(self) -> Vec<(PathBuf, bool)> {
1116 let mut dirs = Vec::new();
1117 for dir in self.bundled.into_iter().chain(self.system) {
1118 if dir.is_dir() {
1119 dirs.push((dir, false));
1120 }
1121 }
1122 if let Some(dir) = self.custom
1123 && dir.is_dir()
1124 {
1125 dirs.push((dir, true));
1126 }
1127 dirs
1128 }
1129 }
1130
1131 /// Extract the intent color sections into a flat `HashMap` with dotted keys
1132 /// like `"surface.page"`, `"status.danger"`, `"category.one"`.
1133 pub fn extract_colors(table: &toml::Table) -> HashMap<String, String> {
1134 let mut colors = HashMap::new();
1135 for section in COLOR_SECTIONS {
1136 if let Some(sect) = table.get(*section).and_then(|s| s.as_table()) {
1137 for (key, val) in sect {
1138 if let Some(color) = val.as_str() {
1139 colors.insert(format!("{section}.{key}"), color.to_string());
1140 }
1141 }
1142 }
1143 }
1144 colors
1145 }
1146
1147 /// Scan directories for `.toml` theme files and return metadata for each.
1148 ///
1149 /// Directories are checked in order; later entries override earlier ones by ID.
1150 /// Each entry in `dirs` is `(path, is_custom)`.
1151 pub fn list_themes_from_dirs(dirs: &[(PathBuf, bool)]) -> Vec<ThemeMeta> {
1152 let mut seen: HashMap<String, ThemeMeta> = HashMap::new();
1153
1154 for (dir, is_custom) in dirs {
1155 let Ok(entries) = std::fs::read_dir(dir) else {
1156 continue;
1157 };
1158
1159 for entry in entries {
1160 let Ok(entry) = entry else {
1161 continue;
1162 };
1163 let path = entry.path();
1164 if path.extension().and_then(|e| e.to_str()) != Some("toml") {
1165 continue;
1166 }
1167
1168 let id = path
1169 .file_stem()
1170 .and_then(|s| s.to_str())
1171 .unwrap_or_default()
1172 .to_string();
1173
1174 let Ok(content) = std::fs::read_to_string(&path) else {
1175 continue;
1176 };
1177 let table: toml::Table = match content.parse() {
1178 Ok(t) => t,
1179 Err(_) => continue,
1180 };
1181
1182 seen.insert(id.clone(), parse_meta(&id, &table, *is_custom));
1183 }
1184 }
1185
1186 let mut themes: Vec<ThemeMeta> = seen.into_values().collect();
1187 themes.sort_by(|a, b| a.name.cmp(&b.name));
1188 themes
1189 }
1190
1191 /// Find a theme file by ID in the given directories.
1192 ///
1193 /// Checks directories in reverse order so the highest-priority directory wins.
1194 /// Returns `(path, is_custom)` or `None` if not found.
1195 pub fn find_theme_path(dirs: &[(PathBuf, bool)], id: &str) -> Option<(PathBuf, bool)> {
1196 let filename = format!("{id}.toml");
1197
1198 for (dir, is_custom) in dirs.iter().rev() {
1199 let path = dir.join(&filename);
1200 if path.is_file() {
1201 return Some((path, *is_custom));
1202 }
1203 }
1204
1205 None
1206 }
1207
1208 /// Parse a complete theme (metadata + colors) from raw TOML content, with no
1209 /// filesystem access. For callers that embed themes at compile time.
1210 pub fn parse_theme_str(id: &str, content: &str, is_custom: bool) -> Result<ThemeColors, String> {
1211 validate_theme_id(id)?;
1212 let table: toml::Table = content
1213 .parse()
1214 .map_err(|e| format!("Failed to parse theme '{id}': {e}"))?;
1215 let meta = parse_meta(id, &table, is_custom);
1216 let colors = extract_colors(&table);
1217 Ok(ThemeColors { meta, colors })
1218 }
1219
1220 /// Load a complete theme (metadata + colors) by ID from the given directories.
1221 pub fn load_theme(dirs: &[(PathBuf, bool)], id: &str) -> Result<ThemeColors, String> {
1222 validate_theme_id(id)?;
1223
1224 let (path, is_custom) =
1225 find_theme_path(dirs, id).ok_or_else(|| format!("Theme '{id}' not found"))?;
1226
1227 let content = std::fs::read_to_string(&path)
1228 .map_err(|e| format!("Failed to read {}: {}", path.display(), e))?;
1229
1230 let table: toml::Table = content
1231 .parse()
1232 .map_err(|e| format!("Failed to parse {}: {}", path.display(), e))?;
1233
1234 let meta = parse_meta(id, &table, is_custom);
1235 let colors = extract_colors(&table);
1236
1237 Ok(ThemeColors { meta, colors })
1238 }
1239
1240 /// Load a theme and resolve it to the full intent token set in one step.
1241 pub fn load_semantic(dirs: &[(PathBuf, bool)], id: &str) -> Result<SemanticTokens, String> {
1242 Ok(resolve(&load_theme(dirs, id)?))
1243 }
1244
1245 /// Import a theme TOML file into the custom themes directory.
1246 ///
1247 /// Validates that the file is parseable TOML with at least one intent color
1248 /// section, then copies it to `custom_dir/{id}.toml`. Returns the theme metadata.
1249 pub fn import_theme(source_path: &Path, custom_dir: &Path) -> Result<ThemeMeta, String> {
1250 let content = std::fs::read_to_string(source_path)
1251 .map_err(|e| format!("Failed to read {}: {}", source_path.display(), e))?;
1252
1253 let table: toml::Table = content.parse().map_err(|e| format!("Invalid TOML: {e}"))?;
1254
1255 let has_colors = COLOR_SECTIONS
1256 .iter()
1257 .any(|s| table.get(*s).and_then(|v| v.as_table()).is_some());
1258 if !has_colors {
1259 return Err(format!(
1260 "Theme file must have at least one color section ({})",
1261 COLOR_SECTIONS.join(", ")
1262 ));
1263 }
1264
1265 let id = source_path
1266 .file_stem()
1267 .and_then(|s| s.to_str())
1268 .ok_or("Invalid file name")?
1269 .to_string();
1270 validate_theme_id(&id)?;
1271
1272 std::fs::create_dir_all(custom_dir)
1273 .map_err(|e| format!("Failed to create {}: {}", custom_dir.display(), e))?;
1274
1275 let dest = custom_dir.join(format!("{id}.toml"));
1276 std::fs::copy(source_path, &dest).map_err(|e| format!("Failed to copy theme: {e}"))?;
1277
1278 Ok(parse_meta(&id, &table, true))
1279 }
1280
1281 /// Delete a custom theme by ID.
1282 ///
1283 /// Only operates on `custom_dir` — bundled themes are not deletable through
1284 /// this entry point.
1285 pub fn delete_theme(custom_dir: &Path, id: &str) -> Result<(), String> {
1286 validate_theme_id(id)?;
1287
1288 let path = custom_dir.join(format!("{id}.toml"));
1289 if !path.is_file() {
1290 return Err(format!("Custom theme '{id}' not found"));
1291 }
1292
1293 std::fs::remove_file(&path).map_err(|e| format!("Failed to delete {}: {}", path.display(), e))
1294 }
1295
1296 /// A four-color preview for theme thumbnails: the representative swatch from
1297 /// each of the principal roles.
1298 #[derive(Debug, Clone, Serialize)]
1299 #[serde(rename_all = "camelCase")]
1300 pub struct ThemePreview {
1301 pub meta: ThemeMeta,
1302 /// Page background (`surface.page`).
1303 pub background: Option<String>,
1304 /// Body text (`content.primary`).
1305 pub foreground: Option<String>,
1306 /// Brand/interactive color (`action.primary`).
1307 pub accent: Option<String>,
1308 /// Divider/outline color (`line.border`).
1309 pub border: Option<String>,
1310 }
1311
1312 fn color_at(table: &toml::Table, section: &str, key: &str) -> Option<String> {
1313 table
1314 .get(section)
1315 .and_then(|s| s.as_table())
1316 .and_then(|s| s.get(key))
1317 .and_then(|v| v.as_str())
1318 .map(std::string::ToString::to_string)
1319 }
1320
1321 /// Load just the preview swatches for a theme — for UI thumbnails.
1322 pub fn load_theme_preview(dirs: &[(PathBuf, bool)], id: &str) -> Result<ThemePreview, String> {
1323 validate_theme_id(id)?;
1324
1325 let (path, is_custom) =
1326 find_theme_path(dirs, id).ok_or_else(|| format!("Theme '{id}' not found"))?;
1327
1328 let content = std::fs::read_to_string(&path)
1329 .map_err(|e| format!("Failed to read {}: {}", path.display(), e))?;
1330
1331 let table: toml::Table = content
1332 .parse()
1333 .map_err(|e| format!("Failed to parse {}: {}", path.display(), e))?;
1334
1335 Ok(ThemePreview {
1336 meta: parse_meta(id, &table, is_custom),
1337 background: color_at(&table, "surface", "page"),
1338 foreground: color_at(&table, "content", "primary"),
1339 accent: color_at(&table, "action", "primary"),
1340 border: color_at(&table, "line", "border"),
1341 })
1342 }
1343
1344 /// Export a theme to a user-chosen path.
1345 pub fn export_theme(dirs: &[(PathBuf, bool)], id: &str, dest_path: &Path) -> Result<(), String> {
1346 validate_theme_id(id)?;
1347
1348 let (source, _) = find_theme_path(dirs, id).ok_or_else(|| format!("Theme '{id}' not found"))?;
1349
1350 std::fs::copy(&source, dest_path).map_err(|e| format!("Failed to export theme: {e}"))?;
1351
1352 Ok(())
1353 }
1354
1355 /// The themes this crate ships, embedded at compile time.
1356 ///
1357 /// `include_dir` is an implementation detail: the public API hands back plain
1358 /// `(id, toml_source)` pairs, so how the data is embedded can change without
1359 /// a breaking release.
1360 static EMBEDDED: include_dir::Dir<'static> =
1361 include_dir::include_dir!("$CARGO_MANIFEST_DIR/themes");
1362
1363 /// The themes this crate ships, as `(id, toml_source)` pairs.
1364 ///
1365 /// This is the path-free way to reach the bundled set, for consumers that
1366 /// cannot rely on a directory existing at runtime: a crate pulled from
1367 /// crates.io lives in a registry checkout whose location is not knowable at
1368 /// compile time, so `include_dir!` and asset-bundling globs in the depending
1369 /// crate have nothing stable to point at. Embedding here and re-exporting the
1370 /// contents gives them one source of truth without a path.
1371 ///
1372 /// Ordering follows the embedded directory and is not guaranteed; collect and
1373 /// sort by id where a stable order matters (a theme picker, say).
1374 pub fn embedded_themes() -> impl Iterator<Item = (&'static str, &'static str)> {
1375 EMBEDDED.files().filter_map(|file| {
1376 let path = file.path();
1377 if path.extension().and_then(|e| e.to_str()) != Some("toml") {
1378 return None;
1379 }
1380 let id = path.file_stem()?.to_str()?;
1381 Some((id, file.contents_utf8()?))
1382 })
1383 }
1384
1385 /// The theme directory this crate ships, for use as a build-from-source
1386 /// fallback.
1387 ///
1388 /// Resolves against `makeover`'s own manifest directory, fixed at compile
1389 /// time, so it works from a path dependency and from a cargo git checkout
1390 /// alike. Installed systems should put their packaged theme directory ahead
1391 /// of this in the search path; this is the entry that keeps `cargo run` in a
1392 /// fresh clone from coming up with no themes at all.
1393 ///
1394 /// Returns `None` when the directory is absent — a cargo cache that has been
1395 /// cleaned, or a vendored copy that dropped the data — so callers degrade to
1396 /// their remaining search path rather than failing.
1397 pub fn bundled_themes_dir() -> Option<PathBuf> {
1398 let themes = Path::new(env!("CARGO_MANIFEST_DIR")).join("themes");
1399 if themes.is_dir() { Some(themes) } else { None }
1400 }
1401
1402 #[cfg(test)]
1403 mod tests {
1404 use super::*;
1405 use std::fs;
1406
1407 // ---- id validation ----
1408
1409 #[test]
1410 fn validate_theme_id_alphanumeric() {
1411 assert!(validate_theme_id("darkmode").is_ok());
1412 assert!(validate_theme_id("Theme123").is_ok());
1413 }
1414
1415 #[test]
1416 fn validate_theme_id_hyphens_underscores() {
1417 assert!(validate_theme_id("dark-mode").is_ok());
1418 assert!(validate_theme_id("my_theme_v2").is_ok());
1419 }
1420
1421 #[test]
1422 fn validate_theme_id_rejects_path_traversal() {
1423 assert!(validate_theme_id("../etc/passwd").is_err());
1424 assert!(validate_theme_id("foo/bar").is_err());
1425 assert!(validate_theme_id("theme.toml").is_err());
1426 }
1427
1428 // ---- low-color terminals ----
1429
1430 #[test]
1431 fn the_ansi_palette_is_sixteen_distinct_colors() {
1432 let mut seen: Vec<(u8, u8, u8)> = ANSI_16.iter().map(|c| c.tuple()).collect();
1433 seen.sort_unstable();
1434 seen.dedup();
1435 assert_eq!(seen.len(), 16);
1436 }
1437
1438 // ---- the intent-to-slot table ----
1439
1440 // Sixteen slots, every one of them answered. A caller filling a terminal
1441 // palette has no fallback for a hole: the slot would keep whatever the
1442 // emulator started with, and one raw ANSI colour in a themed table is more
1443 // obviously wrong than all sixteen would be.
1444 #[test]
1445 fn every_ansi_slot_names_an_intent_on_either_polarity() {
1446 for variant in ["light", "dark", "high-contrast"] {
1447 for index in 0..16 {
1448 assert!(
1449 ansi_intent(index, variant).is_some(),
1450 "slot {index} unanswered on {variant}"
1451 );
1452 }
1453 assert_eq!(ansi_intent(16, variant), None);
1454 }
1455 }
1456
1457 // The property the four achromatic slots exist to hold: 0 is the darkest
1458 // tone the theme offers and 15 the lightest, in either polarity. A table
1459 // that pins slot 0 to `content.primary` passes this on a light theme and
1460 // inverts on a dark one, which is the bug the polarity split fixes.
1461 #[test]
1462 fn ansi_zero_is_darker_than_ansi_fifteen_on_either_polarity() {
1463 for id in ["akari-dawn", "akari-night"] {
1464 let theme = bundled(id);
1465 let slot = |i: usize| -> Rgb {
1466 let key = ansi_intent(i, &theme.meta.variant).expect("in range");
1467 Rgb::from_hex(theme.colors.get(key).expect("theme carries it")).expect("valid hex")
1468 };
1469 assert!(
1470 rel_luminance(slot(0)) < rel_luminance(slot(15)),
1471 "{id}: ANSI 0 {} should be darker than ANSI 15 {}",
1472 slot(0).to_hex(),
1473 slot(15).to_hex(),
1474 );
1475 }
1476 }
1477
1478 // The pair a greeter draws with: its container on 7, its text on 0. If
1479 // those collapse the login screen is one flat block, and slot 7 being a
1480 // surface rather than a text tone is what keeps them apart.
1481 #[test]
1482 fn the_container_slot_and_the_text_slot_stay_legible() {
1483 for id in ["akari-dawn", "akari-night"] {
1484 let theme = bundled(id);
1485 let slot = |i: usize| -> Rgb {
1486 let key = ansi_intent(i, &theme.meta.variant).expect("in range");
1487 Rgb::from_hex(theme.colors.get(key).expect("theme carries it")).expect("valid hex")
1488 };
1489 let contrast = wcag_contrast(slot(0), slot(7));
1490 assert!(contrast >= 4.5, "{id}: ANSI 0 on ANSI 7 is {contrast:.2}:1");
1491 }
1492 }
1493
1494 // The hues do not move with polarity. Red is the theme's danger tone on a
1495 // light theme and on a dark one, which is why only four slots are in the
1496 // polarity table at all.
1497 #[test]
1498 fn the_chromatic_slots_do_not_vary_with_polarity() {
1499 for index in [1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14] {
1500 assert_eq!(
1501 ansi_intent(index, "light"),
1502 ansi_intent(index, "dark"),
1503 "slot {index} moved with polarity"
1504 );
1505 }
1506 }
1507
1508 fn bundled(id: &str) -> ThemeColors {
1509 let dir = bundled_themes_dir().expect("makeover ships its themes");
1510 load_theme(&[(dir, false)], id).expect("the akari pair ships")
1511 }
1512
1513 #[test]
1514 fn quantize_picks_the_obvious_entry() {
1515 let black = Rgb { r: 0, g: 0, b: 0 };
1516 let white = Rgb {
1517 r: 255,
1518 g: 255,
1519 b: 255,
1520 };
1521 assert_eq!(quantize(black, &ANSI_16), 0);
1522 assert_eq!(quantize(white, &ANSI_16), 15);
1523 }
1524
1525 // Nearest-entry quantization is per-color, so two colors a theme keeps
1526 // apart can arrive as one. These two are both closest to the palette's
1527 // light gray, and a border drawn in one on a page painted the other is not
1528 // drawn at all.
1529 #[test]
1530 fn two_colors_can_quantize_to_one_entry() {
1531 let page = Rgb::from_hex("#a8a8a8").unwrap();
1532 let border = Rgb::from_hex("#b4b4b4").unwrap();
1533
1534 assert_eq!(quantize(page, &ANSI_16), quantize(border, &ANSI_16));
1535 assert_ne!(
1536 quantize_against(border, page, &ANSI_16),
1537 quantize(page, &ANSI_16)
1538 );
1539 }
1540
1541 #[test]
1542 fn quantize_against_keeps_the_border_off_the_page() {
1543 let page = Rgb::from_hex("#e4ded6").unwrap();
1544 let border = Rgb::from_hex("#7f786d").unwrap();
1545
1546 let shown_page = ANSI_16[quantize(page, &ANSI_16)];
1547 let shown_border = ANSI_16[quantize_against(border, page, &ANSI_16)];
1548
1549 assert!(
1550 wcag_contrast(shown_border, shown_page) >= DISTINCT,
1551 "border {} on page {} is {:.2}:1",
1552 shown_border.to_hex(),
1553 shown_page.to_hex(),
1554 wcag_contrast(shown_border, shown_page)
1555 );
1556 }
1557
1558 // A color that already reads against its background is left where it is,
1559 // so this can be applied without redesigning what already worked.
1560 #[test]
1561 fn quantize_against_leaves_a_readable_color_alone() {
1562 let page = Rgb::from_hex("#e4ded6").unwrap();
1563 let text = Rgb::from_hex("#1a1816").unwrap();
1564
1565 assert_eq!(
1566 quantize_against(text, page, &ANSI_16),
1567 quantize(text, &ANSI_16)
1568 );
1569 }
1570
1571 // With nothing in the palette to satisfy the request, the most legible
1572 // entry is the answer. Returning the nearest one would return the
1573 // background itself, which is the failure this function exists to avoid.
1574 #[test]
1575 fn an_impossible_palette_gets_the_most_legible_entry() {
1576 let page = Rgb::from_hex("#ffffff").unwrap();
1577 let border = Rgb::from_hex("#fefefe").unwrap();
1578 let palette = [
1579 Rgb::from_hex("#ffffff").unwrap(),
1580 Rgb::from_hex("#fdfdfd").unwrap(),
1581 ];
1582
1583 let chosen = palette[quantize_against(border, page, &palette)];
1584 assert_eq!(chosen.to_hex(), "#fdfdfd");
1585 }
1586
1587 // ---- meta ----
1588
1589 #[test]
1590 fn parse_meta_with_name_and_variant() {
1591 let table: toml::Table = "[meta]\nname = \"Nord\"\nvariant = \"light\"\n"
1592 .parse()
1593 .unwrap();
1594 let meta = parse_meta("nord", &table, false);
1595 assert_eq!(meta.id, "nord");
1596 assert_eq!(meta.name, "Nord");
1597 assert_eq!(meta.variant, "light");
1598 assert!(!meta.is_custom);
1599 }
1600
1601 #[test]
1602 fn parse_meta_defaults_to_id_and_dark() {
1603 let table: toml::Table = "".parse().unwrap();
1604 let meta = parse_meta("fallback", &table, true);
1605 assert_eq!(meta.name, "fallback");
1606 assert_eq!(meta.variant, "dark");
1607 assert!(meta.is_custom);
1608 }
1609
1610 // ---- color math (formulas must match the apps they came from) ----
1611
1612 #[test]
1613 fn rgb_hex_roundtrip() {
1614 assert_eq!(
1615 Rgb::from_hex("#6196FF").unwrap(),
1616 Rgb {
1617 r: 0x61,
1618 g: 0x96,
1619 b: 0xff
1620 }
1621 );
1622 assert_eq!(
1623 Rgb::from_hex("#abc").unwrap(),
1624 Rgb {
1625 r: 0xaa,
1626 g: 0xbb,
1627 b: 0xcc
1628 }
1629 );
1630 assert_eq!(
1631 Rgb {
1632 r: 0x61,
1633 g: 0x96,
1634 b: 0xff
1635 }
1636 .to_hex(),
1637 "#6196ff"
1638 );
1639 assert!(Rgb::from_hex("not-a-color").is_none());
1640 }
1641
1642 #[test]
1643 fn oklab_roundtrips_within_tolerance() {
1644 for hex in ["#6196ff", "#2e3440", "#ffffff", "#000000", "#c0392b"] {
1645 let c = Rgb::from_hex(hex).unwrap();
1646 let back = Rgb::from_oklab(c.to_oklab());
1647 // Gamut round-trip is near-exact (±1 per channel from rounding).
1648 assert!((c.r as i16 - back.r as i16).abs() <= 1, "{hex} r");
1649 assert!((c.g as i16 - back.g as i16).abs() <= 1, "{hex} g");
1650 assert!((c.b as i16 - back.b as i16).abs() <= 1, "{hex} b");
1651 }
1652 }
1653
1654 #[test]
1655 fn wcag_contrast_known_pairs() {
1656 let white = Rgb {
1657 r: 255,
1658 g: 255,
1659 b: 255,
1660 };
1661 let black = Rgb { r: 0, g: 0, b: 0 };
1662 assert!((wcag_contrast(white, black) - 21.0).abs() < 0.01);
1663 assert!((wcag_contrast(white, white) - 1.0).abs() < 0.01);
1664 }
1665
1666 #[test]
1667 fn readable_on_picks_by_wcag() {
1668 assert_eq!(
1669 readable_on(Rgb {
1670 r: 255,
1671 g: 255,
1672 b: 255
1673 }),
1674 Rgb { r: 0, g: 0, b: 0 }
1675 );
1676 assert_eq!(
1677 readable_on(Rgb { r: 0, g: 0, b: 0 }),
1678 Rgb {
1679 r: 255,
1680 g: 255,
1681 b: 255
1682 }
1683 );
1684 // A light blue action -> black text reads better.
1685 let action = Rgb::from_hex("#6196ff").unwrap();
1686 assert_eq!(readable_on(action), Rgb { r: 0, g: 0, b: 0 });
1687 }
1688
1689 #[test]
1690 fn lighten_darken_move_oklab_lightness() {
1691 let c = Rgb::from_hex("#6196ff").unwrap();
1692 let l0 = c.to_oklab().l;
1693 assert!(lighten(c, 0.05).to_oklab().l > l0);
1694 assert!(darken(c, 0.05).to_oklab().l < l0);
1695 }
1696
1697 #[test]
1698 fn mix_endpoints_and_midpoint() {
1699 let a = Rgb::from_hex("#000000").unwrap();
1700 let b = Rgb::from_hex("#6196ff").unwrap();
1701 assert_eq!(mix(a, b, 0.0), a);
1702 assert_eq!(mix(a, b, 1.0), b);
1703 // Midpoint sits between the endpoints in OKLab lightness.
1704 let mid = mix(a, b, 0.5).to_oklab().l;
1705 assert!(mid > a.to_oklab().l && mid < b.to_oklab().l);
1706 }
1707
1708 // ---- extract + resolve ----
1709
1710 fn nord_toml() -> &'static str {
1711 r##"
1712 [meta]
1713 name = "Nord"
1714 variant = "dark"
1715
1716 [surface]
1717 page = "#2e3440"
1718 raised = "#3b4252"
1719 sunken = "#434c5e"
1720 overlay = "#3b4252"
1721
1722 [content]
1723 primary = "#d8dee9"
1724 secondary = "#e5e9f0"
1725 muted = "#616e88"
1726
1727 [action]
1728 primary = "#81a1c1"
1729
1730 [status]
1731 danger = "#bf616a"
1732 success = "#a3be8c"
1733 warning = "#ebcb8b"
1734 info = "#88c0d0"
1735
1736 [line]
1737 border = "#4c566a"
1738
1739 [category]
1740 one = "#bf616a"
1741 two = "#a3be8c"
1742 three = "#81a1c1"
1743 four = "#ebcb8b"
1744 five = "#b48ead"
1745 six = "#88c0d0"
1746 "##
1747 }
1748
1749 #[test]
1750 fn extract_colors_reads_intent_sections() {
1751 let table: toml::Table = nord_toml().parse().unwrap();
1752 let colors = extract_colors(&table);
1753 assert_eq!(colors.get("surface.page").unwrap(), "#2e3440");
1754 assert_eq!(colors.get("content.primary").unwrap(), "#d8dee9");
1755 assert_eq!(colors.get("action.primary").unwrap(), "#81a1c1");
1756 assert_eq!(colors.get("status.danger").unwrap(), "#bf616a");
1757 assert_eq!(colors.get("line.border").unwrap(), "#4c566a");
1758 assert_eq!(colors.get("category.five").unwrap(), "#b48ead");
1759 assert_eq!(colors.len(), 19);
1760 }
1761
1762 #[test]
1763 fn resolve_base_intents_passthrough() {
1764 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
1765 let t = resolve(&theme);
1766 assert_eq!(t.hex("surface-page"), Some("#2e3440"));
1767 assert_eq!(t.hex("content"), Some("#d8dee9")); // content.primary -> content
1768 assert_eq!(t.hex("content-muted"), Some("#616e88"));
1769 assert_eq!(t.hex("action"), Some("#81a1c1"));
1770 assert_eq!(t.hex("danger"), Some("#bf616a"));
1771 assert_eq!(t.hex("border"), Some("#4c566a"));
1772 assert_eq!(t.hex("category-five"), Some("#b48ead"));
1773 }
1774
1775 #[test]
1776 fn resolve_derived_intents() {
1777 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
1778 let t = resolve(&theme);
1779 let action = Rgb::from_hex("#81a1c1").unwrap();
1780 let page = Rgb::from_hex("#2e3440").unwrap();
1781 let _ = page;
1782 assert_eq!(
1783 t.hex("action-hover").unwrap(),
1784 lighten(action, 0.05).to_hex()
1785 );
1786 assert_eq!(
1787 t.hex("content-on-action").unwrap(),
1788 readable_on(action).to_hex()
1789 );
1790 assert_eq!(t.hex("focus-ring"), Some("#81a1c1"));
1791 assert_eq!(t.hex("hover-surface"), Some("#434c5e")); // = surface.sunken
1792 // Pruned by the usage audit (0 consumers): action-active, the *-surface
1793 // tints, selection, row-stripe. Apps that need them derive inline via
1794 // the shared mix().
1795 assert!(t.hex("action-active").is_none());
1796 assert!(t.hex("danger-surface").is_none());
1797 assert!(t.hex("selection").is_none());
1798 assert!(t.hex("row-stripe").is_none());
1799 }
1800
1801 #[test]
1802 fn resolve_bevel_intents() {
1803 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
1804 let t = resolve(&theme);
1805 let raised = Rgb::from_hex("#3b4252").unwrap();
1806 assert_eq!(
1807 t.hex("bevel-light").unwrap(),
1808 lighten(raised, 0.14).to_hex()
1809 );
1810 assert_eq!(t.hex("bevel-dark").unwrap(), darken(raised, 0.18).to_hex());
1811 }
1812
1813 // A bevel is two edges around one face, so both edges have to be visibly off
1814 // that face or the control never resolves as lit. The lightening clamps at
1815 // the top of the ramp, which means a theme authoring a white raised surface
1816 // gets a highlight identical to the surface it is meant to sit on.
1817 //
1818 // The list is asserted rather than merely reported so that changing a theme
1819 // has to come here and say so. Shrinking it is the fix; growing it is a
1820 // regression in the theme, not in this derivation.
1821 #[test]
1822 fn bevel_edges_are_distinct_from_their_face() {
1823 const CANNOT_BEVEL: &[&str] = &["neobrute", "oxocarbon-light"];
1824
1825 let mut degenerate: Vec<String> = Vec::new();
1826 for (id, source) in embedded_themes() {
1827 let theme = parse_theme_str(id, source, false).unwrap();
1828 let t = resolve(&theme);
1829 let Some(raised) = t.hex("surface-raised") else {
1830 continue;
1831 };
1832 let light = t.hex("bevel-light").expect("raised implies bevel-light");
1833 let dark = t.hex("bevel-dark").expect("raised implies bevel-dark");
1834 if light == raised || dark == raised {
1835 degenerate.push(id.to_string());
1836 }
1837 }
1838 degenerate.sort();
1839
1840 assert_eq!(
1841 degenerate, CANNOT_BEVEL,
1842 "themes whose raised surface cannot hold both bevel edges"
1843 );
1844 }
1845
1846 // The well inverts by theme, so assert both directions explicitly rather
1847 // than only the one the light themes happen to take.
1848 #[test]
1849 fn resolve_well_intent_follows_the_content_direction() {
1850 // nord is dark: light text on a dark raised surface, so the well goes
1851 // down and away from the text.
1852 let dark = resolve(&parse_theme_str("nord", nord_toml(), false).unwrap());
1853 let dark_raised = Rgb::from_hex("#3b4252").unwrap();
1854 assert_eq!(
1855 dark.hex("surface-well").unwrap(),
1856 darken(dark_raised, 0.09).to_hex()
1857 );
1858
1859 // The shipped light themes take the other branch.
1860 let goingson = embedded_themes()
1861 .into_iter()
1862 .find(|(id, _)| *id == "goingson")
1863 .expect("goingson is embedded")
1864 .1;
1865 let light = resolve(&parse_theme_str("goingson", goingson, false).unwrap());
1866 let light_raised = light
1867 .hex("surface-raised")
1868 .and_then(Rgb::from_hex)
1869 .expect("goingson authors a raised surface");
1870 assert_eq!(
1871 light.hex("surface-well").unwrap(),
1872 lighten(light_raised, 0.07).to_hex()
1873 );
1874 }
1875
1876 // A well is a fill, not an edge, so the only thing that makes it read is
1877 // being a different color from the surface it is cut into.
1878 //
1879 // Same shape and the same asserted-list discipline as
1880 // `bevel_edges_are_distinct_from_their_face`, and it bites the same two
1881 // themes for the same reason: a raised surface already at the top of the
1882 // ramp has nothing lighter to go to.
1883 #[test]
1884 fn well_is_distinct_from_its_face() {
1885 const CANNOT_WELL: &[&str] = &["neobrute", "oxocarbon-light"];
1886
1887 let mut degenerate: Vec<String> = Vec::new();
1888 for (id, source) in embedded_themes() {
1889 let theme = parse_theme_str(id, source, false).unwrap();
1890 let t = resolve(&theme);
1891 let Some(raised) = t.hex("surface-raised") else {
1892 continue;
1893 };
1894 let well = t.hex("surface-well").expect("raised implies surface-well");
1895 if well == raised {
1896 degenerate.push(id.to_string());
1897 }
1898 }
1899 degenerate.sort();
1900
1901 assert_eq!(
1902 degenerate, CANNOT_WELL,
1903 "themes whose raised surface cannot hold a well"
1904 );
1905 }
1906
1907 // Distinct is not the same as visible. A face near the top of the ramp
1908 // clamps partway rather than exactly, which yields a well that differs from
1909 // its face by a hex digit and by nothing the eye can find. `rosepine-dawn`
1910 // authors raised at L=0.987 and gets 0.009 of the 0.07 it asked for.
1911 //
1912 // Worth a separate test from the one above because the fix differs: an
1913 // exactly-degenerate theme needs its raised surface off the ramp end, while
1914 // these need it merely lowered. Both fixes are the theme's, not this
1915 // derivation's, which is why the list is asserted rather than warned about.
1916 #[test]
1917 fn well_is_visible_against_its_face() {
1918 // Below this, the well and its face are the same surface to a reader.
1919 const MIN_DELTA_L: f32 = 0.02;
1920 const CANNOT_HOLD_A_VISIBLE_WELL: &[&str] =
1921 &["neobrute", "oxocarbon-light", "rosepine-dawn"];
1922
1923 let mut invisible: Vec<String> = Vec::new();
1924 for (id, source) in embedded_themes() {
1925 let theme = parse_theme_str(id, source, false).unwrap();
1926 let t = resolve(&theme);
1927 let (Some(raised), Some(well)) = (
1928 t.hex("surface-raised").and_then(Rgb::from_hex),
1929 t.hex("surface-well").and_then(Rgb::from_hex),
1930 ) else {
1931 continue;
1932 };
1933 if (well.to_oklab().l - raised.to_oklab().l).abs() < MIN_DELTA_L {
1934 invisible.push(id.to_string());
1935 }
1936 }
1937 invisible.sort();
1938
1939 assert_eq!(
1940 invisible, CANNOT_HOLD_A_VISIBLE_WELL,
1941 "themes whose well is too close to its face to read as one"
1942 );
1943 }
1944
1945 // The three tests above each measure a derived color against the face it was
1946 // derived from, so a theme can pass all of them and still have nothing lift
1947 // off anything: the face itself sits on the page, and that relationship is
1948 // the one a bevel needs in order to read as an object rather than as a
1949 // rectangle with decorated edges. makenot.work passed all three and could
1950 // not hold a bevel, which is what this covers.
1951 //
1952 // The threshold is picked against the ramps already ruled on rather than
1953 // against a round number. makenot.work shipped at 0.024 and was invisible,
1954 // was tried at 0.036 and rejected as marginal on badges and chips, and was
1955 // accepted at 0.058; goingson and audiofiles sit at 0.119 and 0.065. Every
1956 // ramp judged inadequate is below 0.036 and every one judged adequate is
1957 // above 0.058, so the line goes in the gap between them. Note the unit: this
1958 // is oklab L on 0 to 1, not the CIE L* on 0 to 100 that the theme files quote
1959 // in their comments, and the two are not interchangeable.
1960 //
1961 // Most of the list is imported palettes, which were authored for syntax
1962 // highlighting and owe our depth model nothing. Failing here says a theme
1963 // cannot hold a bevel, not that it is wrong. Shrinking the list is the fix;
1964 // growing it is a regression in the theme, not in this derivation.
1965 #[test]
1966 fn raised_is_distinct_from_page() {
1967 // Below this, a raised surface and the page under it are one surface to
1968 // a reader, whichever direction the theme ramps in.
1969 const MIN_DELTA_L: f32 = 0.05;
1970 const CANNOT_LIFT_OFF_THE_PAGE: &[&str] = &[
1971 "akari-dawn",
1972 "akari-night",
1973 "ayu-light",
1974 "ayu-mirage",
1975 "catppuccin-latte",
1976 "catppuccin-mocha",
1977 "dawnfox",
1978 "dracula",
1979 "everforest",
1980 "flatwhite",
1981 "gruvbox-light",
1982 "neobrute",
1983 "one-dark",
1984 "oxocarbon-dark",
1985 "oxocarbon-light",
1986 "poimandres",
1987 "rosepine",
1988 "rosepine-dawn",
1989 "solarized-dark",
1990 "tokyonight",
1991 ];
1992
1993 let mut flat: Vec<String> = Vec::new();
1994 for (id, source) in embedded_themes() {
1995 let theme = parse_theme_str(id, source, false).unwrap();
1996 let t = resolve(&theme);
1997 let (Some(page), Some(raised)) = (
1998 t.hex("surface-page").and_then(Rgb::from_hex),
1999 t.hex("surface-raised").and_then(Rgb::from_hex),
2000 ) else {
2001 continue;
2002 };
2003 if (raised.to_oklab().l - page.to_oklab().l).abs() < MIN_DELTA_L {
2004 flat.push(id.to_string());
2005 }
2006 }
2007 flat.sort();
2008
2009 assert_eq!(
2010 flat, CANNOT_LIFT_OFF_THE_PAGE,
2011 "themes whose raised surface is too close to the page to lift off it"
2012 );
2013 }
2014
2015 // What the bevel pair does on a sixteen-color terminal, measured across the
2016 // shipped set rather than assumed. Two results, both load-bearing for a
2017 // consumer that has to render one there.
2018 //
2019 // Exactly one edge survives, never both. A raised face quantizes onto one of
2020 // the palette's three grays, and the palette is too coarse to hold anything
2021 // between that entry and its neighbour, so whichever edge is pushed toward
2022 // the end of the ramp the face already sits on lands back on the face. Light
2023 // themes and most dark ones keep the shadow and lose the highlight; a face
2024 // that quantizes to black keeps the highlight and loses the shadow.
2025 //
2026 // So a low-color consumer draws the single edge it can render, on the side
2027 // the palette left it, rather than a bevel that resolves on two sides.
2028 //
2029 // And `quantize_against` is the wrong function for this pair, though it is
2030 // the right one for a border. It answers "nearest entry that clears DISTINCT
2031 // against the background", which has no notion of direction, so both edges
2032 // are pushed onto the same contrasting entry and the bevel inverts on one
2033 // side. Plain `quantize` keeps them apart and in the right order.
2034 #[test]
2035 fn a_sixteen_color_terminal_gets_one_bevel_edge_and_not_two() {
2036 for (id, source) in embedded_themes() {
2037 let theme = parse_theme_str(id, source, false).unwrap();
2038 let t = resolve(&theme);
2039 let (Some(face), Some(light), Some(dark)) = (
2040 t.hex("surface-raised").and_then(Rgb::from_hex),
2041 t.hex("bevel-light").and_then(Rgb::from_hex),
2042 t.hex("bevel-dark").and_then(Rgb::from_hex),
2043 ) else {
2044 continue;
2045 };
2046
2047 let face_index = quantize(face, &ANSI_16);
2048 let light_survives = quantize(light, &ANSI_16) != face_index;
2049 let dark_survives = quantize(dark, &ANSI_16) != face_index;
2050 assert!(
2051 light_survives != dark_survives,
2052 "{id}: expected exactly one bevel edge to survive 16 colors, \
2053 highlight {light_survives} shadow {dark_survives}"
2054 );
2055
2056 // Direction-blind, so it collapses the pair it is asked to separate.
2057 assert_eq!(
2058 quantize_against(light, face, &ANSI_16),
2059 quantize_against(dark, face, &ANSI_16),
2060 "{id}: quantize_against is expected to be unusable for a bevel pair"
2061 );
2062 }
2063 }
2064
2065 // 256 colors is where the bevel starts working. At 16 every shipped theme
2066 // loses an edge; here all but the five whose raised surface sits at the very
2067 // top of the ramp keep both, and those five fail for the reason they fail in
2068 // truecolor rather than for a palette reason.
2069 //
2070 // Three of them cannot bevel at any depth, so they are the
2071 // `bevel_edges_are_distinct_from_their_face` set. The other two are new here:
2072 // they hold a highlight in 24-bit, but not one wide enough to survive
2073 // rounding onto the cube.
2074 #[test]
2075 fn two_hundred_fifty_six_colors_keep_both_bevel_edges() {
2076 const LOSES_AN_EDGE: &[&str] = &[
2077 "gruvbox-light",
2078 "neobrute",
2079 "oxocarbon-light",
2080 "rosepine-dawn",
2081 ];
2082
2083 let mut lost: Vec<String> = Vec::new();
2084 for (id, source) in embedded_themes() {
2085 let theme = parse_theme_str(id, source, false).unwrap();
2086 let t = resolve(&theme);
2087 let (Some(face), Some(light), Some(dark)) = (
2088 t.hex("surface-raised").and_then(Rgb::from_hex),
2089 t.hex("bevel-light").and_then(Rgb::from_hex),
2090 t.hex("bevel-dark").and_then(Rgb::from_hex),
2091 ) else {
2092 continue;
2093 };
2094
2095 // Against the fixed region, which is what a consumer should use: a
2096 // match in the low sixteen is a match against a repaintable color.
2097 let f = quantize(face, ANSI_240);
2098 let l = quantize(light, ANSI_240);
2099 let d = quantize(dark, ANSI_240);
2100 if l == f || d == f || l == d {
2101 lost.push(id.to_string());
2102 }
2103 }
2104 lost.sort();
2105
2106 assert_eq!(
2107 lost, LOSES_AN_EDGE,
2108 "themes that cannot hold a two-tone bevel on a 256-color terminal"
2109 );
2110 }
2111
2112 #[test]
2113 fn the_256_table_has_its_three_regions() {
2114 // Index is the escape-sequence index, so the low sixteen must match.
2115 assert_eq!(ANSI_256[..16], ANSI_16);
2116 // The cube's corners, at both ends and one interior level.
2117 assert_eq!(ANSI_256[16].tuple(), (0, 0, 0));
2118 assert_eq!(ANSI_256[231].tuple(), (255, 255, 255));
2119 assert_eq!(ANSI_256[16 + 36 * 2 + 6 * 3 + 4].tuple(), (135, 175, 215));
2120 // The gray ramp runs 8 to 238 and contains neither black nor white.
2121 assert_eq!(ANSI_256[232].tuple(), (8, 8, 8));
2122 assert_eq!(ANSI_256[255].tuple(), (238, 238, 238));
2123 // The fixed region is the table minus the repaintable colors.
2124 assert_eq!(ANSI_240.len(), 240);
2125 assert_eq!(ANSI_240[0], ANSI_256[ANSI_240_OFFSET]);
2126 }
2127
2128 #[test]
2129 fn resolve_overlay_is_dark_translucent_scrim() {
2130 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
2131 let t = resolve(&theme);
2132 let overlay = t.hex("overlay").unwrap();
2133 assert!(
2134 overlay.starts_with("rgba("),
2135 "overlay is translucent: {overlay}"
2136 );
2137 assert!(overlay.ends_with(", 0.5)"));
2138 // The scrim tone is anchored very dark regardless of theme.
2139 let inner = overlay
2140 .trim_start_matches("rgba(")
2141 .trim_end_matches(", 0.5)");
2142 let parts: Vec<u8> = inner.split(", ").map(|p| p.parse().unwrap()).collect();
2143 let scrim = Rgb {
2144 r: parts[0],
2145 g: parts[1],
2146 b: parts[2],
2147 };
2148 assert!(scrim.to_oklab().l < 0.2, "scrim must be near-black");
2149 }
2150
2151 /// Every shipped theme derives it, on both polarities, and it is always a
2152 /// near-black translucent tone. A shadow tinted to a dark theme's own
2153 /// lightness would not read as one.
2154 #[test]
2155 fn elevation_is_a_near_black_cast_on_every_theme() {
2156 for (id, source) in embedded_themes() {
2157 let theme = parse_theme_str(id, source, false).unwrap();
2158 let t = resolve(&theme);
2159 let Some(elevation) = t.hex("elevation") else {
2160 panic!("{id} derives no elevation");
2161 };
2162 assert!(
2163 elevation.starts_with("rgba(") && elevation.ends_with(", 0.18)"),
2164 "{id}: elevation is translucent: {elevation}"
2165 );
2166 let inner = elevation
2167 .trim_start_matches("rgba(")
2168 .trim_end_matches(", 0.18)");
2169 let parts: Vec<u8> = inner.split(", ").map(|p| p.parse().unwrap()).collect();
2170 let cast = Rgb {
2171 r: parts[0],
2172 g: parts[1],
2173 b: parts[2],
2174 };
2175 assert!(
2176 cast.to_oklab().l < 0.2,
2177 "{id}: a cast shadow must be near-black, got {elevation}"
2178 );
2179 }
2180 }
2181
2182 /// The scrim and the cast share an anchor and differ only in weight. Stated
2183 /// as a test because the two are easy to drift apart, and a scrim that
2184 /// stopped matching the shadow under the thing it dims would show.
2185 #[test]
2186 fn elevation_and_the_scrim_are_the_same_tone() {
2187 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
2188 let t = resolve(&theme);
2189 let scrim = t.hex("overlay").unwrap();
2190 let cast = t.hex("elevation").unwrap();
2191 assert_eq!(
2192 scrim.trim_end_matches(", 0.5)"),
2193 cast.trim_end_matches(", 0.18)"),
2194 );
2195 }
2196
2197 /// The accessor that makes a translucent intent reachable from something
2198 /// that is not a stylesheet. Both spellings, and an opaque token answers
2199 /// 255 so a caller need not know which kind it asked for.
2200 #[test]
2201 fn rgba_reads_both_spellings() {
2202 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
2203 let t = resolve(&theme);
2204
2205 let (_, _, _, opaque) = t.rgba("surface-page").expect("page is a hex token");
2206 assert_eq!(opaque, 255);
2207
2208 let (r, g, b, alpha) = t.rgba("elevation").expect("elevation is translucent");
2209 assert_eq!(alpha, 46, "0.18 of 255");
2210 assert_eq!(t.rgb("elevation"), None, "rgb declines to drop the alpha");
2211
2212 let (sr, sg, sb, scrim) = t.rgba("overlay").expect("overlay is translucent");
2213 assert_eq!((sr, sg, sb), (r, g, b), "one tone, two weights");
2214 assert_eq!(scrim, 128);
2215 }
2216
2217 #[test]
2218 fn resolve_drops_non_hex_base_intent() {
2219 // A base intent that isn't a hex color must never reach the resolved
2220 // token set (it would otherwise be inlined verbatim into a <style>
2221 // block). Skipped like a missing intent; valid siblings survive.
2222 let theme = parse_theme_str(
2223 "x",
2224 "[surface]\npage = \"</style><script>alert(1)</script>\"\n[content]\nprimary = \"#111111\"\n",
2225 false,
2226 )
2227 .unwrap();
2228 let t = resolve(&theme);
2229 assert!(
2230 t.hex("surface-page").is_none(),
2231 "non-hex base intent leaked"
2232 );
2233 assert_eq!(t.hex("content").unwrap(), "#111111");
2234 // The injected markup appears in no resolved value.
2235 assert!(!t.intents.values().any(|v| v.contains('<')));
2236 }
2237
2238 #[test]
2239 fn resolve_skips_derived_when_source_missing() {
2240 // No [action] => no action-derived tokens.
2241 let theme = parse_theme_str(
2242 "x",
2243 "[surface]\npage = \"#000000\"\n[line]\nborder = \"#222222\"\n",
2244 false,
2245 )
2246 .unwrap();
2247 let t = resolve(&theme);
2248 assert!(t.hex("action").is_none());
2249 assert!(t.hex("action-hover").is_none());
2250 assert!(t.hex("selection").is_none());
2251 assert_eq!(
2252 t.hex("border-strong").unwrap(),
2253 darken(Rgb::from_hex("#222222").unwrap(), 0.05).to_hex()
2254 );
2255 }
2256
2257 #[test]
2258 fn rgb_accessor_for_native_consumers() {
2259 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
2260 let t = resolve(&theme);
2261 assert_eq!(t.rgb("action"), Some((0x81, 0xa1, 0xc1)));
2262 assert_eq!(t.rgb("nonexistent"), None);
2263 }
2264
2265 // ---- css emit ----
2266
2267 #[test]
2268 fn intent_css_vars_wraps_root_and_includes_tokens() {
2269 let theme = parse_theme_str("nord", nord_toml(), false).unwrap();
2270 let css = intent_css_vars(&resolve(&theme));
2271 assert!(css.starts_with(":root {\n"));
2272 assert!(css.contains(" --surface-page: #2e3440;\n"));
2273 assert!(css.contains(" --danger: #bf616a;\n"));
2274 assert!(css.contains(" --action-hover: "));
2275 assert!(css.trim_end().ends_with('}'));
2276 }
2277
2278 // ---- loading / fs ----
2279
2280 #[test]
2281 fn load_and_resolve_round_trip() {
2282 let dir = tempfile::tempdir().unwrap();
2283 fs::write(dir.path().join("nord.toml"), nord_toml()).unwrap();
2284 let dirs = vec![(dir.path().to_path_buf(), false)];
2285 let t = load_semantic(&dirs, "nord").unwrap();
2286 assert_eq!(t.meta.name, "Nord");
2287 assert_eq!(t.hex("action"), Some("#81a1c1"));
2288 }
2289
2290 #[test]
2291 fn load_theme_rejects_invalid_id() {
2292 assert!(load_theme(&[], "../evil").is_err());
2293 }
2294
2295 fn meta(id: &str, variant: &str) -> ThemeMeta {
2296 ThemeMeta {
2297 id: id.to_string(),
2298 name: id.to_string(),
2299 variant: variant.to_string(),
2300 is_custom: false,
2301 }
2302 }
2303
2304 fn defaults() -> ThemeDefaults {
2305 ThemeDefaults::new("flatwhite", "nord")
2306 }
2307
2308 // The three the shipped themes actually declare.
2309 #[test]
2310 fn every_shipped_variant_parses() {
2311 assert_eq!(Variant::parse("light"), Some(Variant::Light));
2312 assert_eq!(Variant::parse("dark"), Some(Variant::Dark));
2313 assert_eq!(Variant::parse("high-contrast"), Some(Variant::HighContrast));
2314 assert_eq!(Variant::parse("sepia"), None);
2315 }
2316
2317 // parse_meta already defaults a *missing* variant to dark, so an
2318 // unrecognized one reading as light would have the crate disagreeing with
2319 // itself. alloy_tui did exactly that before this existed.
2320 #[test]
2321 fn an_unrecognized_variant_reads_the_way_a_missing_one_does() {
2322 assert_eq!(Variant::from("sepia"), Variant::Dark);
2323 assert_eq!(Variant::from(""), Variant::Dark);
2324
2325 let missing: toml::Table = "[meta]\nname = \"X\"\n".parse().unwrap();
2326 assert_eq!(parse_meta("x", &missing, false).kind(), Variant::Dark);
2327 }
2328
2329 #[test]
2330 fn a_selection_round_trips_through_any_store() {
2331 for (stored, expect) in [
2332 (Some("system"), ThemeSelection::Follow),
2333 (None, ThemeSelection::Follow),
2334 (Some(""), ThemeSelection::Follow),
2335 (Some(" "), ThemeSelection::Follow),
2336 (Some("nord"), ThemeSelection::Fixed("nord".into())),
2337 ] {
2338 let parsed = ThemeSelection::parse(stored);
2339 assert_eq!(parsed, expect, "{stored:?}");
2340 assert_eq!(
2341 ThemeSelection::parse(Some(parsed.as_str())),
2342 expect,
2343 "what is written reads back as what was meant",
2344 );
2345 }
2346 }
2347
2348 // Nothing saved is follow-the-system, which is what Balanced Breakfast
2349 // expressed as an absent value and GoingsOn as a sentinel. Both are now the
2350 // same thing.
2351 #[test]
2352 fn nothing_chosen_yet_is_follow() {
2353 assert_eq!(ThemeSelection::default(), ThemeSelection::Follow);
2354 }
2355
2356 #[test]
2357 fn a_fixed_selection_wins_when_its_theme_is_installed() {
2358 let available = [meta("nord", "dark"), meta("flatwhite", "light")];
2359 let fixed = ThemeSelection::Fixed("nord".into());
2360 assert_eq!(
2361 fixed.resolve(Variant::Light, &defaults(), &available),
2362 "nord",
2363 "a chosen theme is not overridden by the ambient mode",
2364 );
2365 }
2366
2367 // Themes are deletable in three of the four apps. Handing back an id that
2368 // will fail to load only moves the error somewhere less helpful.
2369 #[test]
2370 fn a_fixed_selection_whose_theme_is_gone_falls_back() {
2371 let available = [meta("nord", "dark"), meta("flatwhite", "light")];
2372 let fixed = ThemeSelection::Fixed("deleted".into());
2373 assert_eq!(
2374 fixed.resolve(Variant::Light, &defaults(), &available),
2375 "flatwhite",
2376 );
2377 }
2378
2379 #[test]
2380 fn follow_picks_the_apps_default_for_the_ambient_mode() {
2381 let available = [meta("nord", "dark"), meta("flatwhite", "light")];
2382 let follow = ThemeSelection::Follow;
2383 assert_eq!(
2384 follow.resolve(Variant::Dark, &defaults(), &available),
2385 "nord",
2386 );
2387 assert_eq!(
2388 follow.resolve(Variant::Light, &defaults(), &available),
2389 "flatwhite",
2390 );
2391 }
2392
2393 // The behaviour Balanced Breakfast could not have: following the system
2394 // into a theme the user installed, when the app's own default is absent.
2395 #[test]
2396 fn follow_uses_any_installed_theme_of_the_right_variant() {
2397 let available = [meta("solarized-light", "light"), meta("mine", "dark")];
2398 assert_eq!(
2399 ThemeSelection::Follow.resolve(Variant::Dark, &defaults(), &available),
2400 "mine",
2401 "the app's `nord` is not installed, but a dark theme is",
2402 );
2403 }
2404
2405 // Always returns something: an app with no theme directory gets the id it
2406 // ships with, and the load error it would have had anyway.
2407 #[test]
2408 fn an_empty_catalog_still_names_the_apps_default() {
2409 assert_eq!(
2410 ThemeSelection::Follow.resolve(Variant::Dark, &defaults(), &[]),
2411 "nord",
2412 );
2413 }
2414
2415 #[test]
2416 fn high_contrast_falls_back_to_dark_unless_named() {
2417 let plain = defaults();
2418 assert_eq!(plain.for_variant(Variant::HighContrast), "nord");
2419
2420 let named = defaults().high_contrast("sharp");
2421 assert_eq!(named.for_variant(Variant::HighContrast), "sharp");
2422 }
2423
2424 // The bug this builder exists to prevent: the Alloy console pushed the
2425 // user's directory first under a comment reading "highest precedence
2426 // first", when both consumers of this vector resolve last-wins. A custom
2427 // theme lost to the packaged one of the same id.
2428 #[test]
2429 fn the_users_own_themes_outrank_everything() {
2430 let root = tempfile::tempdir().unwrap();
2431 let make = |name: &str| {
2432 let dir = root.path().join(name);
2433 std::fs::create_dir_all(&dir).unwrap();
2434 dir
2435 };
2436 let (bundled, system, custom) = (make("bundled"), make("system"), make("custom"));
2437
2438 let dirs = ThemeDirs::new()
2439 .custom(Some(custom.clone()))
2440 .bundled(Some(bundled.clone()))
2441 .system(Some(system.clone()))
2442 .build();
2443
2444 assert_eq!(
2445 dirs,
2446 vec![(bundled, false), (system, false), (custom.clone(), true)],
2447 "lowest precedence first, whatever order the tiers were added in",
2448 );
2449 assert!(dirs.last().unwrap().1, "only the user's tier is custom");
2450
2451 // And the ordering means what the consumers think it means.
2452 for dir in dirs.iter().map(|(dir, _)| dir) {
2453 std::fs::write(dir.join("shared.toml"), "[meta]\nname = \"x\"\n").unwrap();
2454 }
2455 assert_eq!(
2456 find_theme_path(&dirs, "shared").unwrap().0,
2457 custom.join("shared.toml"),
2458 "the user's copy is the one that loads",
2459 );
2460 }
2461
2462 #[test]
2463 fn a_directory_that_does_not_exist_is_dropped() {
2464 let root = tempfile::tempdir().unwrap();
2465 let real = root.path().join("real");
2466 std::fs::create_dir_all(&real).unwrap();
2467
2468 let dirs = ThemeDirs::new()
2469 .bundled(Some(root.path().join("nope")))
2470 .system(None)
2471 .custom(Some(real.clone()))
2472 .build();
2473
2474 assert_eq!(dirs, vec![(real, true)]);
2475 }
2476
2477 // A Tauri app has two bundled tiers: the resource dir in production and the
2478 // tree build.rs materialized for a dev run with no resource dir.
2479 #[test]
2480 fn more_than_one_bundled_tier_is_allowed() {
2481 let root = tempfile::tempdir().unwrap();
2482 let (first, second) = (root.path().join("a"), root.path().join("b"));
2483 std::fs::create_dir_all(&first).unwrap();
2484 std::fs::create_dir_all(&second).unwrap();
2485
2486 let dirs = ThemeDirs::new()
2487 .bundled(Some(first.clone()))
2488 .bundled(Some(second.clone()))
2489 .build();
2490 assert_eq!(dirs, vec![(first, false), (second, false)]);
2491 }
2492
2493 #[test]
2494 fn list_themes_from_dirs_finds_toml_files() {
2495 let dir = tempfile::tempdir().unwrap();
2496 fs::write(dir.path().join("t.toml"), "[meta]\nname = \"T\"\n").unwrap();
2497 fs::write(dir.path().join("x.txt"), "ignored").unwrap();
2498 let dirs = vec![(dir.path().to_path_buf(), false)];
2499 let themes = list_themes_from_dirs(&dirs);
2500 assert_eq!(themes.len(), 1);
2501 assert_eq!(themes[0].id, "t");
2502 }
2503
2504 #[test]
2505 fn find_theme_path_reverse_priority() {
2506 let d1 = tempfile::tempdir().unwrap();
2507 let d2 = tempfile::tempdir().unwrap();
2508 fs::write(d1.path().join("s.toml"), "[meta]\n").unwrap();
2509 fs::write(d2.path().join("s.toml"), "[meta]\n").unwrap();
2510 let dirs = vec![
2511 (d1.path().to_path_buf(), false),
2512 (d2.path().to_path_buf(), true),
2513 ];
2514 let (path, is_custom) = find_theme_path(&dirs, "s").unwrap();
2515 assert!(is_custom);
2516 assert_eq!(path, d2.path().join("s.toml"));
2517 }
2518
2519 #[test]
2520 fn import_theme_valid_and_rejects_empty() {
2521 let src_dir = tempfile::tempdir().unwrap();
2522 let custom_dir = tempfile::tempdir().unwrap();
2523
2524 let good = src_dir.path().join("my-theme.toml");
2525 fs::write(&good, "[surface]\npage = \"#1a1b26\"\n").unwrap();
2526 let meta = import_theme(&good, custom_dir.path()).unwrap();
2527 assert_eq!(meta.id, "my-theme");
2528 assert!(custom_dir.path().join("my-theme.toml").exists());
2529
2530 let empty = src_dir.path().join("empty.toml");
2531 fs::write(&empty, "[meta]\nname = \"E\"\n").unwrap();
2532 assert!(import_theme(&empty, custom_dir.path()).is_err());
2533 }
2534
2535 #[test]
2536 fn import_theme_rejects_invalid_toml() {
2537 let src_dir = tempfile::tempdir().unwrap();
2538 let custom_dir = tempfile::tempdir().unwrap();
2539 let src = src_dir.path().join("bad.toml");
2540 fs::write(&src, "this is not [valid toml [[[").unwrap();
2541 assert!(import_theme(&src, custom_dir.path()).is_err());
2542 }
2543
2544 #[test]
2545 fn delete_theme_removes_and_guards() {
2546 let custom = tempfile::tempdir().unwrap();
2547 let path = custom.path().join("doomed.toml");
2548 fs::write(&path, "[surface]\npage = \"#000\"\n").unwrap();
2549 delete_theme(custom.path(), "doomed").unwrap();
2550 assert!(!path.exists());
2551 assert!(delete_theme(custom.path(), "../etc/passwd").is_err());
2552 assert!(delete_theme(custom.path(), "ghost").is_err());
2553 }
2554
2555 #[test]
2556 fn export_theme_copies_file() {
2557 let src_dir = tempfile::tempdir().unwrap();
2558 let dest_dir = tempfile::tempdir().unwrap();
2559 let content = "[meta]\nname = \"E\"\n[surface]\npage = \"#ffffff\"\n";
2560 fs::write(src_dir.path().join("e.toml"), content).unwrap();
2561 let dirs = vec![(src_dir.path().to_path_buf(), false)];
2562 let dest = dest_dir.path().join("out.toml");
2563 export_theme(&dirs, "e", &dest).unwrap();
2564 assert_eq!(fs::read_to_string(&dest).unwrap(), content);
2565 assert!(export_theme(&dirs, "missing", &dest).is_err());
2566 }
2567
2568 #[test]
2569 fn load_theme_preview_returns_role_swatches() {
2570 let dir = tempfile::tempdir().unwrap();
2571 fs::write(dir.path().join("nord.toml"), nord_toml()).unwrap();
2572 let dirs = vec![(dir.path().to_path_buf(), false)];
2573 let p = load_theme_preview(&dirs, "nord").unwrap();
2574 assert_eq!(p.background.as_deref(), Some("#2e3440")); // surface.page
2575 assert_eq!(p.foreground.as_deref(), Some("#d8dee9")); // content.primary
2576 assert_eq!(p.accent.as_deref(), Some("#81a1c1")); // action.primary
2577 assert_eq!(p.border.as_deref(), Some("#4c566a")); // line.border
2578 }
2579
2580 #[test]
2581 fn bundled_themes_dir_resolves_to_shipped_themes() {
2582 // The crate ships its themes, so this must resolve in-tree and the
2583 // Akari defaults the console falls back to must be present.
2584 let dir = bundled_themes_dir().expect("makeover ships a themes/ directory");
2585 assert!(dir.join("akari-dawn.toml").is_file());
2586 assert!(dir.join("akari-night.toml").is_file());
2587 }
2588
2589 #[test]
2590 fn every_theme_is_accounted_for_in_third_party_notices() {
2591 // Attribution is a redistribution obligation, not a nicety: adding a
2592 // theme without a notice entry silently ships someone's work
2593 // uncredited. Fail here instead.
2594 let notices = std::fs::read_to_string(
2595 Path::new(env!("CARGO_MANIFEST_DIR")).join("THIRD-PARTY-NOTICES.md"),
2596 )
2597 .expect("THIRD-PARTY-NOTICES.md must exist");
2598 let missing: Vec<&str> = embedded_themes()
2599 .map(|(id, _)| id)
2600 .filter(|id| !notices.contains(*id))
2601 .collect();
2602 assert!(
2603 missing.is_empty(),
2604 "themes missing from THIRD-PARTY-NOTICES.md: {missing:?}"
2605 );
2606 }
2607
2608 #[test]
2609 fn adapted_themes_carry_inline_attribution() {
2610 // Each adapted file must name its upstream in-file, so the credit
2611 // survives someone copying a single .toml out of the crate.
2612 const ORIGINALS: [&str; 5] = [
2613 "makenotwork",
2614 "goingson",
2615 "audiofiles",
2616 "high-contrast",
2617 "neobrute",
2618 ];
2619 for (id, source) in embedded_themes() {
2620 if ORIGINALS.contains(&id) {
2621 continue;
2622 }
2623 assert!(
2624 source.contains("adapted from"),
2625 "adapted theme `{id}` is missing its inline attribution header"
2626 );
2627 }
2628 }
2629
2630 #[test]
2631 fn embedded_themes_match_the_directory() {
2632 // The embedded copy and themes/ are two views of one source. If they
2633 // ever disagree, path-based and path-free consumers render different
2634 // theme sets, which is exactly the drift shipping the data was meant
2635 // to prevent.
2636 let dir = bundled_themes_dir().unwrap();
2637 let mut on_disk: Vec<String> = std::fs::read_dir(&dir)
2638 .unwrap()
2639 .filter_map(|e| {
2640 let path = e.ok()?.path();
2641 if path.extension()? != "toml" {
2642 return None;
2643 }
2644 Some(path.file_stem()?.to_str()?.to_string())
2645 })
2646 .collect();
2647 let mut embedded: Vec<String> = embedded_themes().map(|(id, _)| id.to_string()).collect();
2648 on_disk.sort();
2649 embedded.sort();
2650 assert_eq!(embedded, on_disk, "embedded theme set drifted from themes/");
2651 }
2652
2653 #[test]
2654 fn every_embedded_theme_parses() {
2655 // Guards the path-free consumers (MNW server, the Tauri build steps)
2656 // the same way every_shipped_theme_loads guards the path-based ones.
2657 let mut count = 0;
2658 for (id, source) in embedded_themes() {
2659 parse_theme_str(id, source, false)
2660 .unwrap_or_else(|e| panic!("embedded theme `{id}` failed to parse: {e}"));
2661 count += 1;
2662 }
2663 assert!(count >= 30, "expected the full theme set, got {count}");
2664 }
2665
2666 #[test]
2667 fn every_shipped_theme_loads() {
2668 // Guards the data, not just the loader: a malformed or truncated
2669 // .toml in themes/ is a shipping bug, and it should fail here rather
2670 // than at a user's first launch.
2671 let dir = bundled_themes_dir().unwrap();
2672 let dirs = vec![(dir.clone(), false)];
2673 let themes = list_themes_from_dirs(&dirs);
2674 assert!(
2675 themes.len() >= 30,
2676 "expected the full theme set, got {}",
2677 themes.len()
2678 );
2679 for meta in &themes {
2680 load_theme(&dirs, &meta.id)
2681 .unwrap_or_else(|e| panic!("shipped theme `{}` failed to load: {e}", meta.id));
2682 }
2683 }
2684 }
2685