max / makenotwork

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1	//! Guards against tri-source enum drift: every domain enum's variant set must
2	//! equal the Postgres `CHECK (... IN (...))` list on its backing column. The
3	//! enums decode fail-closed (an unknown string errors the whole row read), so a
4	//! value the DB permits but the Rust enum can't decode would poison any query
5	//! that touches such a row. This test makes that drift fail in CI instead of at
6	//! the first read of a poisoned row.
7	//!
8	//! `EnumType::VARIANTS` is the single source of truth (generated by
9	//! `impl_str_enum!`); the DB side is read from the live, fully-migrated schema
10	//! so later `ALTER ... CHECK` migrations are accounted for.
11
12	use crate::harness::TestHarness;
13	use makenotwork::db;
14	use std::collections::BTreeSet;
15
16	/// Extract the single-quoted string literals from a `pg_get_constraintdef`
17	/// rendering (Postgres renders `col IN ('a','b')` as
18	/// `CHECK ((col)::text = ANY (ARRAY['a'::text, 'b'::text]))`; the allowed values
19	/// are exactly the single-quoted tokens).
20	fn quoted_values(constraint_def: &str) -> BTreeSet<String> {
21	let mut out = BTreeSet::new();
22	let mut chars = constraint_def.char_indices().peekable();
23	while let Some((_, c)) = chars.next() {
24	if c == '\'' {
25	let mut val = String::new();
26	for (_, c2) in chars.by_ref() {
27	if c2 == '\'' {
28	break;
29	}
30	val.push(c2);
31	}
32	out.insert(val);
33	}
34	}
35	out
36	}
37
38	/// Read the union of allowed values across every single-column CHECK constraint
39	/// on exactly `table.column`. Constraining to `conkey = [column]` excludes
40	/// cross-column CHECKs (which would leak an unrelated column's literals).
41	async fn db_check_values(pool: &sqlx::PgPool, table: &str, column: &str) -> BTreeSet<String> {
42	let defs: Vec<String> = sqlx::query_scalar(
43	"SELECT pg_get_constraintdef(c.oid) \
44	FROM pg_constraint c JOIN pg_class t ON t.oid = c.conrelid \
45	WHERE t.relname = $1 AND c.contype = 'c' \
46	AND c.conkey = ARRAY[ \
47	(SELECT a.attnum FROM pg_attribute a WHERE a.attrelid = t.oid AND a.attname = $2) \
48	]::smallint[]",
49	)
50	.bind(table)
51	.bind(column)
52	.fetch_all(pool)
53	.await
54	.unwrap();
55
56	assert!(
57	!defs.is_empty(),
58	"no CHECK constraint found on {table}.{column} — update the enum-drift registry"
59	);
60	defs.iter().flat_map(\|d\| quoted_values(d)).collect()
61	}
62
63	fn variant_set(variants: &[&str]) -> BTreeSet<String> {
64	variants
65	.iter()
66	.map(std::string::ToString::to_string)
67	.collect()
68	}
69
70	#[tokio::test]
71	async fn enum_variants_match_db_check_constraints() {
72	let h = TestHarness::new().await;
73
74	// (label, table, column, Rust variant set). Each pair's DB CHECK list must
75	// equal the enum's VARIANTS. Add a row when a new enum backs a CHECK column.
76	// Only enum-backed columns that actually carry an `IN (...)` CHECK. Columns
77	// that store a broad external status set (e.g. subscriptions.status mirrors
78	// Stripe) intentionally have no CHECK and are not listed. Grow this as new
79	// CHECK-constrained enum columns land.
80	let cases: Vec<(&str, &str, &str, BTreeSet<String>)> = vec![
81	(
82	"TransactionStatus",
83	"transactions",
84	"status",
85	variant_set(db::TransactionStatus::VARIANTS),
86	),
87	(
88	"DiscountType",
89	"promo_codes",
90	"discount_type",
91	variant_set(db::DiscountType::VARIANTS),
92	),
93	(
94	"CodePurpose",
95	"promo_codes",
96	"code_purpose",
97	variant_set(db::CodePurpose::VARIANTS),
98	),
99	(
100	"FollowTargetType",
101	"follows",
102	"target_type",
103	variant_set(db::FollowTargetType::VARIANTS),
104	),
105	];
106
107	let mut failures = Vec::new();
108	for (label, table, column, variants) in &cases {
109	let db_values = db_check_values(&h.db, table, column).await;
110	if &db_values != variants {
111	failures.push(format!(
112	"{label} ({table}.{column}):\n rust VARIANTS = {variants:?}\n db CHECK = {db_values:?}"
113	));
114	}
115	}
116
117	assert!(
118	failures.is_empty(),
119	"enum <-> DB CHECK drift detected:\n{}",
120	failures.join("\n")
121	);
122	}
123