Add deterministic test sharding for distributed CI

src/config.zigmodified+25-0

Changes to src/config.zig

		⋯7 linesShow the 7 lines above this hunk@@ -8,6 +8,7 @@ pub const ConfigFormat = enum { json };
8	8	/// actually honor. Defaults intentionally match `CLIOptions`.
9	9	pub const TestConfig = struct {
10	10	test_options: TestOptions = .{},
	11	+ sharding: ShardingOptions = .{},
11	12	parallel: ParallelOptions = .{},
12	13	reporter: ReporterOptions = .{},
13	14	snapshot: SnapshotOptions = .{},
		⋯3 linesShow the 3 lines above this hunk@@ -17,6 +18,11 @@ pub const TestConfig = struct {
17	18	coverage: CoverageOptions = .{},
18	19	};
19	20
	21	+pub const ShardingOptions = struct {
	22	+ index: ?usize = null,
	23	+ count: ?usize = null,
	24	+};
	25	+
20	26	pub const TestOptions = struct {
21	27	pattern: []const u8 = "*.test.zig",
22	28	test_dir: []const u8 = ".",
		⋯41 linesShow the 41 lines above this hunk@@ -64,6 +70,7 @@ pub const CoverageOptions = struct {
64	70
65	71	const FileConfig = struct {
66	72	@"test": TestOptions = .{},
	73	+ sharding: ShardingOptions = .{},
67	74	parallel: ParallelOptions = .{},
68	75	reporter: ReporterOptions = .{},
69	76	snapshot: SnapshotOptions = .{},
		⋯10 linesShow the 10 lines above this hunk@@ -80,6 +87,7 @@ pub const ConfigError = error{
80	87	InvalidPort,
81	88	InvalidTimeout,
82	89	InvalidDebounce,
	90	+ InvalidShard,
83	91	};
84	92
85	93	/// Owns strings parsed from configuration files until `deinit` is called.
		⋯30 linesShow the 30 lines above this hunk@@ -116,6 +124,7 @@ pub const ConfigLoader = struct {
116	124	);
117	125	const config = TestConfig{
118	126	.test_options = file_config.@"test",
	127	+ .sharding = file_config.sharding,
119	128	.parallel = file_config.parallel,
120	129	.reporter = file_config.reporter,
121	130	.snapshot = file_config.snapshot,
		⋯53 linesShow the 53 lines above this hunk@@ -175,6 +184,13 @@ fn validate(config: TestConfig) !void {
175	184	if (timeout == 0) return ConfigError.InvalidTimeout;
176	185	}
177	186	if (config.watch.debounce_ms == 0) return ConfigError.InvalidDebounce;
	187	+ const has_shard_index = config.sharding.index != null;
	188	+ const has_shard_count = config.sharding.count != null;
	189	+ if (has_shard_index != has_shard_count) return ConfigError.InvalidShard;
	190	+ if (config.sharding.count) |count| {
	191	+ const index = config.sharding.index.?;
	192	+ if (count == 0 or index == 0 or index > count) return ConfigError.InvalidShard;
	193	+ }
178	194	}
179	195
180	196	test "TestConfig defaults match CLI discovery defaults" {
		⋯2 linesShow the 2 lines above this hunk@@ -183,6 +199,8 @@ test "TestConfig defaults match CLI discovery defaults" {
183	199	try std.testing.expectEqualStrings(".", config.test_options.test_dir);
184	200	try std.testing.expect(config.test_options.recursive);
185	201	try std.testing.expect(config.test_options.timeout == null);
	202	+ try std.testing.expect(config.sharding.index == null);
	203	+ try std.testing.expect(config.sharding.count == null);
186	204	try std.testing.expect(!config.parallel.enabled);
187	205	try std.testing.expectEqualStrings("spec", config.reporter.reporter);
188	206	}
		⋯11 linesShow the 11 lines above this hunk@@ -200,6 +218,11 @@ test "configuration validation rejects invalid runtime values" {
200	218	invalid.reporter.reporter = "spec";
201	219	invalid.parallel.jobs = 0;
202	220	try std.testing.expectError(ConfigError.InvalidJobs, validate(invalid));
	221	+ invalid.parallel.jobs = null;
	222	+ invalid.sharding.index = 2;
	223	+ try std.testing.expectError(ConfigError.InvalidShard, validate(invalid));
	224	+ invalid.sharding.count = 1;
	225	+ try std.testing.expectError(ConfigError.InvalidShard, validate(invalid));
203	226	}
204	227
205	228	test "ConfigLoader loads supported JSON and rejects unknown keys" {
		⋯4 linesShow the 4 lines above this hunk@@ -210,6 +233,8 @@ test "ConfigLoader loads supported JSON and rejects unknown keys" {
210	233	try std.testing.expectEqualStrings("tests/fixtures", config.test_options.test_dir);
211	234	try std.testing.expectEqualStrings("selected test passes", config.test_options.filter.?);
212	235	try std.testing.expect(!config.test_options.recursive);
	236	+ try std.testing.expectEqual(@as(?usize, 1), config.sharding.index);
	237	+ try std.testing.expectEqual(@as(?usize, 1), config.sharding.count);
213	238
214	239	try std.testing.expectError(
215	240	error.UnknownField,