Files
PaperClipAI/scripts/__tests__/run-vitest-stable-shard.test.mjs
T
352153b5ed fix: run the cargo-building native-runner CI suite in the Rust-cached vitest lane (#13586)
## Thinking Path

Post-merge of #13557, the slowest check on the freshest fully-green PR
run
([35246999382](https://github.com/paperclipai/paperclip/actions/runs/35246999382))
was `ci / General tests (server (1/12))` at **339s**. The cause is one
suite:
`server/src/services/native-runtime/native-codex-runner.integration.test.ts`
runs 1 test in **277s of a 291s vitest step (95%)** because its
`beforeAll` cargo-builds the Runner release binaries, and the
general-server shards carry no Rust cache — every PR run cold-compiles
the full third-party crate graph. The other 19 suites in that shard
finish in under 70ms each.

The obvious fix (a dedicated Rust-cached matrix lane) requires editing
workflow files, which the available GitHub App credentials cannot push
(`workflows` permission). But the `Verify Paperclip Runner` lanes
**already restore the shared `release-runner-v1` Rust cache read-only**,
and their commands are `pnpm --filter @paperclipai/paperclip-runner
<package script>` — so the suite can move into a Rust-cached lane purely
through script changes.

## What Changed

- `scripts/run-vitest-stable.mjs`: new `general-server-native-runner`
group carrying exactly that suite. Under the PR workflow
(`GITHUB_WORKFLOW == "PR"`, inherited from `pr.yml` by the reusable
`pr-trusted.yml`) the without-chat server shards exclude it and
rebalance to ~211s of tests each. Every other caller — local runs,
`release-verify.yml` under the Release / Cloud readiness workflows —
keeps the suite in the shards, so a renamed or unknown workflow degrades
to today's slower-but-covered behavior instead of dropping coverage.
- `packages/paperclip-runner`: `test:typescript:vitest` now routes
through `scripts/run-pr-vitest-lane.mjs` — the identical
`ensure:eval-build-deps && build:rust && vitest run` chain (shard flags
passed through), plus the native-runner group on the **final PR shard
only** (`--shard=N/M` with `N == M`, i.e. today's `vitest 2/2`, the 122s
lane). With the restored cache the suite's cargo build becomes an
incremental rebuild.
- `scripts/__tests__/run-vitest-stable-shard.test.mjs`: guards pin the
whole contract — PR 12-shard coverage (shards + chat + native-runner =
full server group exactly), Release/local 10-shard runs keep the suite,
`pr.yml` is named `PR`, the vitest lanes partition with exactly one
final shard, the package-script wiring, and the wrapper's shard/workflow
gating via its `--dry-run` plan output.

No workflow files change. `.github/workflows/*` are untouched.

## Verification

- `node --test scripts/__tests__/run-vitest-stable-shard.test.mjs
scripts/__tests__/release-verify-workflow.test.mjs`: **36/36 pass**
locally on this branch (includes the new coverage, wiring, and
wrapper-gating guards). Both files run in CI's `Test general-server
shard partition` / `Test release verify workflow wiring` steps.
- Wrapper `--dry-run` plan matrix verified for all six shard/workflow
combinations plus malformed-shard rejection (pinned as a guard test).
- The executing proof is this PR's own CI: `ci / Verify Paperclip Runner
(vitest 2/2)` must go green while running the native-runner suite (its
log will show the `general-server-native-runner` group after the package
vitest shard), and the 12 `ci / General tests (server (x/12))` shards
must go green without it.

## Risks

- The exclusion keys on `GITHUB_WORKFLOW == "PR"`. Failure mode of a
rename is safe (suite falls back into the server shards, slower but
covered) and the guard test on `pr.yml`'s name makes it loud.
- `vitest 2/2` grows from ~122s to an expected ~210–260s — still well
under the ~306s `vitest 1/2` and ~326s e2e shards, and inside the
20-minute lane timeout. If the cache misses (key drift), the lane pays a
cold compile like the server shard does today; a miss is slow, never
wrong.
- Double-run/coverage-loss combinations are enumerated in the wrapper
header and pinned by tests: each caller runs the suite exactly once.

## Model Used

Claude (Bender agent, Paperclip) — Fable 5.

---
Expected savings once merged: the 339s `server (1/12)` check drops to
~265s-equivalent shard levels (~211s of tests), the slowest `ci /` check
becomes the ~326s e2e shard (~13–33s off PR wall time), and every PR run
stops paying ~4.5 min of billed cold Rust compile.

For the merger (squash): please keep the trailer below in the squash
body to preserve authorship.

`Co-Authored-By: Bender (Fable)
<Paperclip-Paperclip@users.noreply.github.com>`

## Related PRs

Searched the GitHub PR list for prior work on this surface — related
groundwork, none duplicate this change:
- #13457 — restored master's Rust dependency cache on the PR runner lane
(the read-only cache this PR relies on)
- #13500 — made that cache key image-toolchain-independent so
GitHub-hosted PR runners actually hit it
- #13521 — rebalanced PR shards and split the Verify Paperclip Runner
lanes this PR extends
- #13557 — previous health-check iteration (split the runnerd transport
suite); this PR targets the next slowest check

## Checklist

- [x] I have searched GitHub for duplicate or related PRs and linked
them above

Co-authored-by: Bender (Fable) <Paperclip-Paperclip@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-09-18 07:22:12 -07:00

431 lines
21 KiB
JavaScript

import assert from "node:assert/strict";
import { spawnSync } from "node:child_process";
import { readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import test from "node:test";
import {
defaultSuiteWeight,
loadShardDurations,
partitionGeneralServerSuites,
} from "../general-server-shard.mjs";
import { assertSelectedTests, partitionTestLines } from "../test-line-shard.mjs";
const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..", "..");
const script = path.join(repoRoot, "scripts", "run-vitest-stable.mjs");
const durationsManifest = path.join(repoRoot, "scripts", "general-server-shard-durations.json");
const serializedDurationsManifest = path.join(
repoRoot,
"scripts",
"serialized-shard-durations.json",
);
// Membership of general-server-without-chat depends on GITHUB_WORKFLOW (see
// prWorkflowName in run-vitest-stable.mjs), so strip the ambient value and
// make every test pin the caller it mirrors explicitly — these tests
// themselves run inside a workflow on CI.
function workflowEnv(envOverrides = {}) {
const env = { ...process.env, ...envOverrides };
if (!("GITHUB_WORKFLOW" in envOverrides)) {
delete env.GITHUB_WORKFLOW;
}
return env;
}
function dryRun(args, envOverrides = {}) {
const result = spawnSync(process.execPath, [script, ...args, "--dry-run"], {
cwd: repoRoot,
encoding: "utf8",
env: workflowEnv(envOverrides),
});
return result;
}
function dryRunJson(args, envOverrides = {}) {
const result = dryRun(args, envOverrides);
assert.equal(result.status, 0, `expected success for ${args.join(" ")}: ${result.stderr}`);
return JSON.parse(result.stdout);
}
const SHARD_COUNT = 12;
const SERIALIZED_SHARD_COUNT = 9;
test("the serialized shards form a complete, non-overlapping partition", () => {
const shards = Array.from({ length: SERIALIZED_SHARD_COUNT }, (_, index) =>
dryRunJson(["--mode", "serialized", "--shard-index", String(index), "--shard-count", String(SERIALIZED_SHARD_COUNT)]),
);
const total = shards[0].serializedSuiteCount;
const selected = shards.flatMap((shard) => shard.selectedSerializedSuites);
assert.equal(selected.length, total, "every serialized suite must be selected exactly once");
assert.equal(new Set(selected).size, total, "serialized shards must not overlap");
});
test("the general-server shards form a complete, non-overlapping partition", () => {
const shards = Array.from({ length: SHARD_COUNT }, (_, index) =>
dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", String(index), "--shard-count", String(SHARD_COUNT)]),
);
const total = shards[0].generalServerSuiteCount;
assert.ok(total > 0, "expected a non-empty general-server suite set");
const seen = new Set();
let selectedTotal = 0;
for (const shard of shards) {
assert.equal(shard.generalServerSuiteCount, total, "suite count must be stable across shards");
for (const file of shard.selectedGeneralServerSuites) {
assert.ok(!seen.has(file), `suite assigned to more than one shard: ${file}`);
seen.add(file);
selectedTotal += 1;
}
}
// Every suite runs exactly once: union covers the whole set with no overlap.
assert.equal(selectedTotal, total, "every suite must be selected exactly once");
assert.equal(seen.size, total, "union of shards must cover the whole suite set");
});
test("a route/authz suite never leaks into the general-server shards", () => {
const shard = dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", "0", "--shard-count", SHARD_COUNT.toString()]);
for (const file of shard.selectedGeneralServerSuites) {
assert.ok(
!/[^/]*(?:route|routes|authz)[^/]*\.test\.ts$/.test(file),
`route/authz suite must stay in the serialized lane, not general-server: ${file}`,
);
}
});
test("shard flags are rejected for the workspaces-b group", () => {
const result = dryRun(["--mode", "general", "--group", "general-workspaces-b", "--shard-index", "0", "--shard-count", "3"]);
assert.notEqual(result.status, 0, "workspaces-b must not accept shard flags");
});
test("workspaces-a shards map to Vitest native --shard slices over a stable project list", () => {
const shards = [0, 1].map((index) =>
dryRunJson([
"--mode", "general", "--group", "general-workspaces-a",
"--shard-index", String(index), "--shard-count", "2",
]),
);
assert.deepEqual(
shards.map((shard) => shard.workspacesVitestShard),
["1/2", "2/2"],
"each matrix job must pass its own --shard slice to vitest",
);
// Vitest's --shard partitions each project's file list deterministically, so
// an identical project list across jobs is what guarantees complete,
// non-overlapping coverage of the lane.
assert.deepEqual(shards[0].workspaceProjects, shards[1].workspaceProjects);
assert.ok(shards[0].workspaceProjects.length > 0, "workspaces-a must run at least one project");
const unsharded = dryRunJson(["--mode", "general", "--group", "general-workspaces-a"]);
assert.deepEqual(
unsharded.workspaceProjects,
shards[0].workspaceProjects,
"sharding must not change which projects the lane covers",
);
assert.equal(unsharded.workspacesVitestShard, null);
});
test("duration-aware partition balances skewed weights better than round-robin", () => {
// Round-robin puts all three heavy suites on shard 0 (indexes 0, 3, 6).
const files = ["a", "b", "c", "d", "e", "f", "g", "h", "i"];
const durations = { a: 30000, d: 30000, g: 30000, b: 100, c: 100, e: 100, f: 100, h: 100, i: 100 };
const shards = partitionGeneralServerSuites(files, 3, durations);
const totals = shards.map((shard) => shard.totalWeight);
const maxTotal = Math.max(...totals);
const minTotal = Math.min(...totals);
assert.ok(
maxTotal - minTotal <= 200,
`expected near-even shard weights, got ${totals.join(", ")}`,
);
assert.equal(
shards.flatMap((shard) => shard.files).sort().join(","),
files.join(","),
"partition must cover every file exactly once",
);
});
test("the partition is deterministic for identical inputs", () => {
const files = Array.from({ length: 50 }, (_, index) => `suite-${index}.test.ts`);
const durations = Object.fromEntries(files.map((file, index) => [file, (index * 37) % 5000]));
const first = partitionGeneralServerSuites(files, 3, durations);
const second = partitionGeneralServerSuites(files, 3, durations);
assert.deepEqual(first, second, "same inputs must always produce the same partition");
});
test("suites missing from the manifest get the median weight", () => {
assert.equal(defaultSuiteWeight({ a: 100, b: 300, c: 900 }), 300);
assert.equal(defaultSuiteWeight({ a: 100, b: 300, c: 500, d: 900 }), 400);
assert.equal(defaultSuiteWeight({}), 1000, "empty manifest falls back to a fixed weight");
});
test("a missing or malformed manifest degrades to uniform weights", () => {
assert.deepEqual(loadShardDurations(path.join(repoRoot, "scripts", "no-such-manifest.json")), {});
const files = ["a", "b", "c", "d"];
const shards = partitionGeneralServerSuites(files, 2, {});
assert.equal(shards[0].files.length + shards[1].files.length, files.length);
assert.equal(Math.abs(shards[0].files.length - shards[1].files.length), 0);
});
test("the checked-in manifest loads and covers most of the current suite set", () => {
const durations = loadShardDurations(durationsManifest);
assert.ok(Object.keys(durations).length > 0, "manifest must parse to a non-empty duration map");
const shard = dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", "0", "--shard-count", "1"]);
const currentFiles = shard.selectedGeneralServerSuites;
const known = currentFiles.filter((file) => durations[file] !== undefined).length;
assert.ok(
known / currentFiles.length >= 0.5,
`manifest is stale: only ${known} of ${currentFiles.length} suites have recorded durations — regenerate it from a recent PR run (see the manifest's $comment)`,
);
});
test("the chat integration suite keeps a measured duration for duration-aware fallbacks", () => {
// The PR and release matrices both run the chat suite in dedicated
// line-sharded lanes, but the plain general-server group (local full runs)
// still weighs it into the LPT partition; a median-fallback weight there
// would silently overload whichever shard receives it.
const chatSuite = "server/src/__tests__/chat-channels.integration.test.ts";
const durations = loadShardDurations(durationsManifest);
assert.ok(
Number.isFinite(durations[chatSuite]),
"the full chat cohort must have a measured duration, not the median fallback",
);
});
test("the checked-in serialized manifest loads and covers most of the current suite set", () => {
const durations = loadShardDurations(serializedDurationsManifest);
assert.ok(Object.keys(durations).length > 0, "manifest must parse to a non-empty duration map");
const shard = dryRunJson(["--mode", "serialized", "--shard-index", "0", "--shard-count", "1"]);
const currentFiles = shard.selectedSerializedSuites;
const known = currentFiles.filter((file) => durations[file] !== undefined).length;
assert.ok(
known / currentFiles.length >= 0.5,
`manifest is stale: only ${known} of ${currentFiles.length} suites have recorded durations — regenerate it from a recent PR run (see the manifest's $comment)`,
);
});
test("the real serialized shard partition is duration-balanced", () => {
const durations = loadShardDurations(serializedDurationsManifest);
const fallback = defaultSuiteWeight(durations);
const shards = Array.from({ length: SERIALIZED_SHARD_COUNT }, (_, index) =>
dryRunJson(["--mode", "serialized", "--shard-index", String(index), "--shard-count", String(SERIALIZED_SHARD_COUNT)]),
);
const totals = shards.map((shard) =>
shard.selectedSerializedSuites.reduce((sum, file) => sum + (durations[file] ?? fallback), 0),
);
const maxTotal = Math.max(...totals);
const minTotal = Math.min(...totals);
// LPT keeps the spread within the heaviest single suite; use that as the bound.
const heaviest = Math.max(...Object.values(durations));
assert.ok(
maxTotal - minTotal <= heaviest,
`serialized shard weight spread ${maxTotal - minTotal}ms exceeds heaviest suite ${heaviest}ms: ${totals.join(", ")}`,
);
});
test("the real shard partition is duration-balanced", () => {
// Mirrors the PR matrix: general-server-without-chat across SHARD_COUNT
// runners, with the chat suite carried by the dedicated general-chat lanes
// and the native-runner suite by the Rust-cached PR vitest lane.
const durations = loadShardDurations(durationsManifest);
const fallback = defaultSuiteWeight(durations);
const shards = Array.from({ length: SHARD_COUNT }, (_, index) =>
dryRunJson(
["--mode", "general", "--group", "general-server-without-chat", "--shard-index", String(index), "--shard-count", String(SHARD_COUNT)],
{ GITHUB_WORKFLOW: "PR" },
),
);
const totals = shards.map((shard) =>
shard.selectedGeneralServerSuites.reduce((sum, file) => sum + (durations[file] ?? fallback), 0),
);
const maxTotal = Math.max(...totals);
const minTotal = Math.min(...totals);
// LPT keeps the spread within the heaviest single suite; use that as the
// bound. The chat and native-runner suites run in their own lanes, so
// exclude them here.
const chat = "server/src/__tests__/chat-channels.integration.test.ts";
const nativeRunner =
"server/src/services/native-runtime/native-codex-runner.integration.test.ts";
const heaviest = Math.max(
...Object.entries(durations)
.filter(([file]) => file !== chat && file !== nativeRunner)
.map(([, ms]) => ms),
);
assert.ok(
maxTotal - minTotal <= heaviest,
`shard weight spread ${maxTotal - minTotal}ms exceeds heaviest suite ${heaviest}ms: ${totals.join(", ")}`,
);
});
const chatSuitePath = "server/src/__tests__/chat-channels.integration.test.ts";
const nativeRunnerSuitePath =
"server/src/services/native-runtime/native-codex-runner.integration.test.ts";
// Mirrors pr-trusted.yml (12 shards, called by pr.yml so GITHUB_WORKFLOW is
// "PR"): the chat suite runs in its dedicated lanes and the cargo-dependent
// native-runner suite in the Rust-cached final Verify Paperclip Runner vitest
// shard, so together the three cover the full server group exactly.
test("12 PR without-chat shards plus the dedicated chat and native-runner lanes cover the original server group exactly", () => {
const prEnv = { GITHUB_WORKFLOW: "PR" };
const full = dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", "0", "--shard-count", "1"], prEnv);
const shards = Array.from({ length: 12 }, (_, index) => dryRunJson([
"--mode", "general", "--group", "general-server-without-chat",
"--shard-index", String(index), "--shard-count", "12",
], prEnv));
const files = shards.flatMap((shard) => shard.selectedGeneralServerSuites);
assert.ok(!files.includes(chatSuitePath));
assert.ok(!files.includes(nativeRunnerSuitePath));
assert.deepEqual([...files, chatSuitePath, nativeRunnerSuitePath].sort(), full.selectedGeneralServerSuites.sort());
assert.equal(new Set(files).size, files.length);
const defaultRun = dryRunJson([], prEnv);
assert.ok(defaultRun.generalServerSuiteCount === full.generalServerSuiteCount);
});
// Mirrors release-verify.yml (10 shards, called by the Release and Cloud
// readiness workflows) and local runs: no Rust-cached vitest lane exists
// there, so the native-runner suite must stay in the server shards.
for (const [caller, envOverrides] of [["Release", { GITHUB_WORKFLOW: "Release" }], ["no ambient workflow", {}]]) {
test(`10 without-chat shards under ${caller} keep the native-runner suite and cover the server group with chat alone`, () => {
const full = dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", "0", "--shard-count", "1"], envOverrides);
const shards = Array.from({ length: 10 }, (_, index) => dryRunJson([
"--mode", "general", "--group", "general-server-without-chat",
"--shard-index", String(index), "--shard-count", "10",
], envOverrides));
const files = shards.flatMap((shard) => shard.selectedGeneralServerSuites);
assert.ok(!files.includes(chatSuitePath));
assert.ok(files.includes(nativeRunnerSuitePath));
assert.deepEqual([...files, chatSuitePath].sort(), full.selectedGeneralServerSuites.sort());
assert.equal(new Set(files).size, files.length);
});
}
test("the native-runner lane runs exactly the cargo-dependent vertical-slice suite", () => {
const lane = dryRunJson(["--mode", "general", "--group", "general-server-native-runner"]);
assert.deepEqual(lane.selectedGeneralServerSuites, [
"server/src/services/native-runtime/native-codex-runner.integration.test.ts",
]);
});
test("shard flags are rejected for the native-runner group", () => {
const result = dryRun(["--mode", "general", "--group", "general-server-native-runner", "--shard-index", "0", "--shard-count", "2"]);
assert.notEqual(result.status, 0, "the native-runner lane is a single suite and must not accept shard flags");
});
// The PR-side exclusion above is safe only while the wiring it assumes holds:
// pr.yml (the caller whose name reusable pr-trusted.yml jobs see as
// GITHUB_WORKFLOW) is named PR, the sharded vitest lanes partition cleanly
// with exactly one final shard, and that lane's package script routes through
// the wrapper that runs the native-runner group.
test("the PR workflow wiring for the native-runner lane holds", () => {
const prWorkflow = readFileSync(path.join(repoRoot, ".github/workflows/pr.yml"), "utf8");
assert.match(prWorkflow, /^name: PR$/m,
"renaming pr.yml silently moves the native-runner suite back into the uncached server shards");
const trustedWorkflow = readFileSync(path.join(repoRoot, ".github/workflows/pr-trusted.yml"), "utf8");
const lanes = [...trustedWorkflow.matchAll(/command: test:typescript:vitest --shard=(\d+)\/(\d+)/g)]
.map((match) => [Number(match[1]), Number(match[2])]);
assert.ok(lanes.length > 0, "expected sharded test:typescript:vitest lanes in pr-trusted.yml");
assert.equal(new Set(lanes.map(([, count]) => count)).size, 1, "vitest lanes must agree on the shard count");
const shardCount = lanes[0][1];
assert.deepEqual(
lanes.map(([index]) => index).sort((left, right) => left - right),
Array.from({ length: shardCount }, (_, index) => index + 1),
"vitest lanes must cover every shard exactly once",
);
assert.equal(lanes.filter(([index, count]) => index === count).length, 1,
"exactly one final vitest shard carries the native-runner group");
const runnerPackage = JSON.parse(
readFileSync(path.join(repoRoot, "packages/paperclip-runner/package.json"), "utf8"),
);
assert.equal(runnerPackage.scripts["test:typescript:vitest"], "node ./scripts/run-pr-vitest-lane.mjs");
});
const laneWrapper = path.join(repoRoot, "packages/paperclip-runner/scripts/run-pr-vitest-lane.mjs");
function wrapperPlan(args, envOverrides = {}) {
const result = spawnSync(process.execPath, [laneWrapper, ...args, "--dry-run"], {
cwd: repoRoot,
encoding: "utf8",
env: workflowEnv(envOverrides),
});
assert.equal(result.status, 0, `expected wrapper dry run to succeed for ${args.join(" ")}: ${result.stderr}`);
return JSON.parse(result.stdout);
}
test("the PR vitest lane wrapper runs the native-runner group exactly on the final PR shard", () => {
for (const [args, envOverrides, expected] of [
[["--shard=1/2"], { GITHUB_WORKFLOW: "PR" }, false],
[["--shard=2/2"], { GITHUB_WORKFLOW: "PR" }, true],
[[], { GITHUB_WORKFLOW: "PR" }, true],
[["--shard=2/2"], { GITHUB_WORKFLOW: "Release" }, false],
[["--shard=2/2"], {}, false],
[[], {}, false],
]) {
const plan = wrapperPlan(args, envOverrides);
assert.equal(plan.runNativeRunnerGroup, expected,
`args ${JSON.stringify(args)} env ${JSON.stringify(envOverrides)}`);
const commands = plan.plannedCommands.map((planned) => planned.args.join(" "));
assert.ok(commands.some((command) => command.startsWith(`exec vitest run${args.length ? ` ${args.join(" ")}` : ""}`)),
"the wrapper must pass shard flags through to vitest");
assert.equal(
commands.some((command) => command.includes("--group general-server-native-runner")),
expected,
);
}
const malformed = spawnSync(process.execPath, [laneWrapper, "--shard=nonsense", "--dry-run"], {
cwd: repoRoot,
encoding: "utf8",
env: workflowEnv({ GITHUB_WORKFLOW: "PR" }),
});
assert.notEqual(malformed.status, 0, "a malformed shard flag must fail rather than guess a lane");
});
const lineShardFile = path.join(repoRoot, "server/src/__tests__/chat-channels.integration.test.ts");
const caseAt = (line, name) => ({ name, file: lineShardFile, projectName: "@paperclipai/server", location: { line, column: 3 } });
test("test-line shards cover nested and parameterized cases exactly once without splitting a source line", () => {
const cases = [caseAt(10, "suite > nested > first"), caseAt(10, "suite > nested > second"),
caseAt(20, "same name"), caseAt(30, "same name"), caseAt(40, "last"), caseAt(50, "new case")];
const shards = partitionTestLines(cases, 3, lineShardFile);
assert.deepEqual(shards.map((shard) => shard.tests.length), [2, 2, 2]);
assert.equal(shards.filter((shard) => shard.lines.includes(10)).length, 1);
assert.equal(shards.find((shard) => shard.lines.includes(10)).tests.length, 2);
assert.equal(shards.flatMap((shard) => shard.lines).length, 5);
assert.deepEqual(shards.flatMap((shard) => shard.tests).sort((a, b) => a.location.line - b.location.line), cases);
assert.deepEqual(partitionTestLines([...cases].reverse(), 3, lineShardFile).map((shard) => shard.lines), shards.map((shard) => shard.lines));
});
test("line-shard collection rejects empty, foreign, or unlocated tests and invalid shard counts", () => {
const good = caseAt(10, "valid");
for (const input of [[], null, [{ ...good, file: "/another.test.ts" }], [{ ...good, projectName: "wrong" }],
[{ ...good, location: undefined }], [{ ...good, location: { line: 0 } }], [{ ...good, name: "" }]]) {
assert.throws(() => partitionTestLines(input, 1, lineShardFile));
}
for (const count of [0, -1, 1.5, Infinity, 2]) assert.throws(() => partitionTestLines([good], count, lineShardFile));
});
test("filtered collection must match the exact assigned case identities, including duplicates", () => {
const expected = [caseAt(10, "same"), caseAt(10, "same"), caseAt(20, "nested > case")];
assertSelectedTests(expected, [...expected].reverse(), lineShardFile);
for (const actual of [expected.slice(1), [...expected, caseAt(30, "extra")],
[expected[0], expected[1], caseAt(20, "renamed")],
[expected[0], expected[1], caseAt(21, "nested > case")]]) {
assert.throws(() => assertSelectedTests(expected, actual, lineShardFile));
}
});