max / makenotwork

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1	//! Write every staged screen's residual to `src/quasi/residuals.rs`.
2	//!
3	//! The build-time half of the declaration transition (quasicoherent
4	//! `793d99dd`). A residual is a screen's markup with the request taken out of
5	//! it, and it is produced by rendering: `quasi_webview::stage::derive` calls
6	//! the screen's staged twin and reads the spans off what the renderer emits. So
7	//! it cannot be produced by this crate's own build script, which cannot link
8	//! the crate it is building. It is produced here instead, by a binary that
9	//! links the crate the ordinary way, and what it writes is Rust source the next
10	//! build compiles.
11	//!
12	//! Rust source and not a serialization format. A format would need a writer, a
13	//! reader, a version and a parse at startup, and the parse is exactly what the
14	//! spike's template intermediate was rejected for. There is no format here: the
15	//! artifact is code, `rustc` is its only reader, and what ships is literals in
16	//! read-only data.
17	//!
18	//! `quasi::residuals::tests::every_committed_residual_matches_a_fresh_one`
19	//! fails when this output is stale, so the regeneration step is:
20	//!
21	//! ```sh
22	//! cargo run --bin export-residuals
23	//! ```
24	//!
25	//! A test rather than only a pre-commit hook, because a residual goes stale for
26	//! two different reasons and a hook catches one of them. A screen changing is
27	//! visible in the diff; quasi-webview changing is not, and under the tree's
28	//! `[patch]` block a renderer edit in another repo silently makes every
29	//! committed residual one version behind. `cargo test` runs against the
30	//! renderer actually linked, so it sees both.
31
32	use std::io::Write as _;
33
34	fn main() -> std::io::Result<()> {
35	let source = makenotwork::quasi::residuals::generate();
36
37	if std::env::args().any(\|argument\| argument == "--stdout") {
38	std::io::stdout().write_all(source.as_bytes())?;
39	return Ok(());
40	}
41
42	let path = concat!(
43	env!("CARGO_MANIFEST_DIR"),
44	"/src/quasi/residuals/compiled.rs"
45	);
46	let mut file = std::fs::File::create(path)?;
47	file.write_all(source.as_bytes())?;
48	println!("wrote {path}");
49	Ok(())
50	}
51