test: reduce suite latency with safe sharding

.changeset/hot-bikes-beg.md

@@ -0,0 +1,2 @@
+---
+---

.github/workflows/pr-ci.yml

@@ -95,7 +95,7 @@ jobs:
         run: bun run test:theme-contrast
 
       - name: Test suite
-        run: bun test ./src ./packages ./scripts ./test/cli ./test/session
+        run: bun run test
 
   compiled-headless-portability:
     name: Compiled headless portability (${{ matrix.os }})

package.json

@@ -82,7 +82,7 @@
     "changeset:status": "bunx @changesets/cli@2.31.0 status",
     "release:version": "bunx @changesets/cli@2.31.0 version",
     "prepare": "simple-git-hooks",
-    "test": "\"${npm_execpath:-bun}\" test ./src ./packages ./scripts ./examples ./test/cli ./test/session",
+    "test": "bun run ./scripts/run-test-suite.ts",
     "test:theme-contrast": "bun test src/ui/themes.test.ts --test-name-pattern contrast",
     "test:integration": "\"${npm_execpath:-bun}\" test ./test/pty",
     "test:tty-smoke": "HUNK_RUN_TTY_SMOKE=1 \"${npm_execpath:-bun}\" test ./test/smoke",

scripts/run-test-suite.test.ts

@@ -0,0 +1,79 @@
+import { describe, expect, test } from "bun:test";
+import {
+  buildTestShardCommand,
+  DEFAULT_TEST_PATTERNS,
+  resolveTestShardCount,
+  terminateTestShardProcesses,
+} from "./run-test-suite";
+
+describe("test suite sharding", () => {
+  test("uses the available CPUs up to the automatic Linux cap", () => {
+    expect(resolveTestShardCount(1, undefined, "linux")).toBe(1);
+    expect(resolveTestShardCount(2, undefined, "linux")).toBe(2);
+    expect(resolveTestShardCount(32, undefined, "linux")).toBe(2);
+  });
+
+  test("accepts an explicit positive shard count on Linux", () => {
+    expect(resolveTestShardCount(32, "1", "linux")).toBe(1);
+    expect(resolveTestShardCount(2, "16", "linux")).toBe(16);
+  });
+
+  test("keeps non-Linux suites serial", () => {
+    expect(resolveTestShardCount(32, undefined, "win32")).toBe(1);
+    expect(resolveTestShardCount(32, "16", "darwin")).toBe(1);
+  });
+
+  test("rejects malformed or excessive Linux shard overrides", () => {
+    expect(() => resolveTestShardCount(8, "0", "linux")).toThrow(
+      "HUNK_TEST_SHARDS must be a positive safe integer",
+    );
+    expect(() => resolveTestShardCount(8, "2.5", "linux")).toThrow(
+      "HUNK_TEST_SHARDS must be a positive safe integer",
+    );
+    expect(() => resolveTestShardCount(8, "999999999999999999999999", "linux")).toThrow(
+      "HUNK_TEST_SHARDS must be a positive safe integer",
+    );
+    expect(() => resolveTestShardCount(8, "65", "linux")).toThrow(
+      "HUNK_TEST_SHARDS cannot exceed 64",
+    );
+  });
+
+  test("builds serial and sharded Bun commands", () => {
+    expect(buildTestShardCommand("/opt/bun", 1, 1, [], "linux")).toEqual([
+      "/opt/bun",
+      "test",
+      "--no-orphans",
+      ...DEFAULT_TEST_PATTERNS,
+    ]);
+    expect(buildTestShardCommand("/opt/bun", 2, 4, ["--rerun-each=2"], "linux")).toEqual([
+      "/opt/bun",
+      "test",
+      "--no-orphans",
+      "--shard=2/4",
+      ...DEFAULT_TEST_PATTERNS,
+      "--rerun-each=2",
+    ]);
+    expect(buildTestShardCommand("C:\\bun.exe", 1, 1, [], "win32")).toEqual([
+      "C:\\bun.exe",
+      "test",
+      ...DEFAULT_TEST_PATTERNS,
+    ]);
+  });
+
+  test("forwards termination while tolerating an already stopped shard", () => {
+    const signals: Array<NodeJS.Signals> = [];
+    terminateTestShardProcesses(
+      [
+        { kill: (signal) => signals.push(signal as NodeJS.Signals) },
+        {
+          kill: () => {
+            throw new Error("already stopped");
+          },
+        },
+      ],
+      "SIGTERM",
+    );
+
+    expect(signals).toEqual(["SIGTERM"]);
+  });
+});

scripts/run-test-suite.ts

@@ -0,0 +1,167 @@
+#!/usr/bin/env bun
+
+/**
+ * Runs Hunk's default tests concurrently without Bun's isolated parallel worker mode.
+ *
+ * Bun 1.3.14's `--parallel` implies `--isolate`, which makes OpenTUI's native FFI
+ * renderer fail to initialize with "Cannot access 'default' before initialization."
+ * Independent `--shard=N/M` processes avoid that failure, but Bun runs only the one
+ * requested shard, so this module launches and supervises every shard. Sharding stays
+ * Linux-only because the complete multi-process suite is validated and benchmarked there.
+ */
+
+import { availableParallelism } from "node:os";
+
+export const DEFAULT_TEST_PATTERNS = [
+  "./src",
+  "./packages",
+  "./scripts",
+  "./examples",
+  "./test/cli",
+  "./test/session",
+] as const;
+
+const MAX_AUTOMATIC_TEST_SHARDS = 2;
+const MAX_EXPLICIT_TEST_SHARDS = 64;
+const SHARD_TERMINATION_GRACE_MS = 1_000;
+
+type KillableProcess = {
+  kill(signal?: number | NodeJS.Signals): void;
+};
+
+/** Resolve a Linux shard override or choose a bounded count from the available CPUs. */
+export function resolveTestShardCount(
+  cpuCount: number,
+  override?: string,
+  platform: NodeJS.Platform = process.platform,
+) {
+  if (platform !== "linux") return 1;
+
+  if (override !== undefined) {
+    const count = Number(override);
+    if (!/^\d+$/.test(override) || !Number.isSafeInteger(count) || count < 1) {
+      throw new Error("HUNK_TEST_SHARDS must be a positive safe integer");
+    }
+    if (count > MAX_EXPLICIT_TEST_SHARDS) {
+      throw new Error(`HUNK_TEST_SHARDS cannot exceed ${MAX_EXPLICIT_TEST_SHARDS}`);
+    }
+    return count;
+  }
+
+  return Math.min(MAX_AUTOMATIC_TEST_SHARDS, Math.max(1, Math.floor(cpuCount)));
+}
+
+/** Build one Bun test command for an independent file shard. */
+export function buildTestShardCommand(
+  bunExecutable: string,
+  shard: number,
+  shardCount: number,
+  forwardedArgs: string[] = [],
+  platform: NodeJS.Platform = process.platform,
+) {
+  return [
+    bunExecutable,
+    "test",
+    ...(platform === "win32" ? [] : ["--no-orphans"]),
+    ...(shardCount > 1 ? [`--shard=${shard}/${shardCount}`] : []),
+    ...DEFAULT_TEST_PATTERNS,
+    ...forwardedArgs,
+  ];
+}
+
+/** Forward a termination signal to every live shard, tolerating shards that already exited. */
+export function terminateTestShardProcesses(processes: KillableProcess[], signal: NodeJS.Signals) {
+  for (const proc of processes) {
+    try {
+      proc.kill(signal);
+    } catch {
+      // Another shard or the terminal process group may already have stopped it.
+    }
+  }
+}
+
+/** Run the default suite in independent Bun processes without enabling Bun's isolate mode. */
+export async function main(args = Bun.argv.slice(2)) {
+  const shardCount = resolveTestShardCount(availableParallelism(), process.env.HUNK_TEST_SHARDS);
+  const bunExecutable = process.execPath;
+
+  console.error(`Running the test suite in ${shardCount} shard${shardCount === 1 ? "" : "s"}...`);
+
+  const shards: Array<{ proc: ReturnType<typeof Bun.spawn>; shard: number }> = [];
+  try {
+    for (let index = 0; index < shardCount; index += 1) {
+      const shard = index + 1;
+      const proc = Bun.spawn(
+        buildTestShardCommand(bunExecutable, shard, shardCount, args, process.platform),
+        {
+          cwd: process.cwd(),
+          env: { ...process.env, npm_execpath: bunExecutable },
+          stdin: "inherit",
+          stdout: "inherit",
+          stderr: "inherit",
+        },
+      );
+      shards.push({ proc, shard });
+    }
+  } catch (error) {
+    const spawnedProcesses = shards.map(({ proc }) => proc);
+    terminateTestShardProcesses(spawnedProcesses, "SIGTERM");
+    const forceKillTimer = setTimeout(() => {
+      terminateTestShardProcesses(spawnedProcesses, "SIGKILL");
+    }, SHARD_TERMINATION_GRACE_MS);
+    forceKillTimer.unref();
+    try {
+      await Promise.allSettled(shards.map(({ proc }) => proc.exited));
+    } finally {
+      clearTimeout(forceKillTimer);
+    }
+    throw error;
+  }
+
+  const processes = shards.map(({ proc }) => proc);
+  let interruptedExitCode: number | null = null;
+  let forceKillTimer: ReturnType<typeof setTimeout> | null = null;
+  const handleSignal = (signal: NodeJS.Signals, exitCode: number) => {
+    if (interruptedExitCode !== null) return;
+    interruptedExitCode = exitCode;
+    terminateTestShardProcesses(processes, signal);
+    forceKillTimer = setTimeout(() => {
+      terminateTestShardProcesses(processes, "SIGKILL");
+    }, SHARD_TERMINATION_GRACE_MS);
+    forceKillTimer.unref();
+  };
+  const handleSigint = () => handleSignal("SIGINT", 130);
+  const handleSigterm = () => handleSignal("SIGTERM", 143);
+  process.once("SIGINT", handleSigint);
+  process.once("SIGTERM", handleSigterm);
+
+  let results: Array<{ exitCode: number; shard: number }>;
+  try {
+    results = await Promise.all(
+      shards.map(async ({ proc, shard }) => ({ exitCode: await proc.exited, shard })),
+    );
+  } finally {
+    process.off("SIGINT", handleSigint);
+    process.off("SIGTERM", handleSigterm);
+    if (forceKillTimer) clearTimeout(forceKillTimer);
+  }
+
+  if (interruptedExitCode !== null) return interruptedExitCode;
+  const failedShards = results.filter(({ exitCode }) => exitCode !== 0);
+
+  if (failedShards.length > 0) {
+    console.error(
+      `Test shard failure: ${failedShards
+        .map(({ exitCode, shard }) => `${shard}/${shardCount} (exit ${exitCode})`)
+        .join(", ")}`,
+    );
+    return 1;
+  }
+
+  console.error(`All ${shardCount} test shard${shardCount === 1 ? "" : "s"} passed.`);
+  return 0;
+}
+
+if (import.meta.main) {
+  process.exitCode = await main();
+}

scripts/verify-pr-release-notes.test.ts

@@ -2,6 +2,7 @@ import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync
 import os from "node:os";
 import path from "node:path";
 import { afterEach, describe, expect, test } from "bun:test";
+import { removeTestDirectory } from "../test/helpers/filesystem";
 import {
   isGeneratedPrereleasePreparation,
   isGeneratedReleasePath,
@@ -88,10 +89,8 @@ function writeGeneratedPrerelease(root: string, initialVersion = "0.17.7") {
   runGit(root, ["commit", "--quiet", "-m", "prepare prerelease"]);
 }
 
-afterEach(() => {
-  for (const root of tempRoots.splice(0)) {
-    rmSync(root, { recursive: true, force: true });
-  }
+afterEach(async () => {
+  await Promise.all(tempRoots.splice(0).map((root) => removeTestDirectory(root)));
 });
 
 describe("isGeneratedReleasePath", () => {

src/extensions/discovery.test.ts

@@ -485,6 +485,7 @@ describe("manifest api version requirements", () => {
       repoRoot: undefined,
       globalExtensionsDir: undefined,
       flagPaths: [folder],
+      env: {},
     });
 
     expect(candidates).toEqual([
@@ -503,6 +504,7 @@ describe("manifest api version requirements", () => {
       repoRoot: undefined,
       globalExtensionsDir: undefined,
       flagPaths: [folder],
+      env: {},
     });
 
     expect(candidates).toEqual([
@@ -524,6 +526,7 @@ describe("manifest api version requirements", () => {
       repoRoot: undefined,
       globalExtensionsDir: undefined,
       flagPaths: [folder],
+      env: {},
     });
 
     expect(candidates).toEqual([{ id: "bad-api-ext", path: entry, origin: "flag" }]);

src/ui/components/scrollbar/VerticalScrollbar.test.tsx

@@ -198,7 +198,7 @@ describe("Vertical scrollbar", () => {
         contentHeight={40}
         theme={theme}
         height={10}
-        hideDelayMs={5}
+        hideDelayMs={120}
       />,
       { width: 2, height: 10 },
     );
@@ -213,8 +213,9 @@ describe("Vertical scrollbar", () => {
       await flush(setup);
       expect(frameHasBackground(setup, theme.accentMuted)).toBe(true);
 
+      // Keep a wide margin beyond the deadline for Windows CI timer granularity.
       await act(async () => {
-        await Bun.sleep(10);
+        await Bun.sleep(180);
       });
       await flush(setup);
       expect(frameHasBackground(setup, theme.accentMuted)).toBe(false);