fix(bun): close late runtime review races

tests/bun/npm-protocol-resolution.test.ts

@@ -3,6 +3,7 @@ import { JSDOM } from "npm:jsdom@28.0.0";
 import { assertEquals } from "#veryfront/testing/assert.ts";
 import { describe, it } from "#veryfront/testing/bdd.ts";
 import { rewriteNpmProtocolImports } from "./npm-protocol-imports.ts";
+import { bunPreloadRewriteFilter, rewriteBunPreloadSource } from "./preload-rewrite.ts";
 
 describe("Bun npm protocol resolution", () => {
   it("loads versioned scoped and unscoped npm imports", () => {
@@ -30,4 +31,45 @@ describe("Bun npm protocol resolution", () => {
       ].join("\n"),
     );
   });
+
+  it("rewrites extension and test sources after normalizing path separators", () => {
+    const extensionSource =
+      'import { defineExtension } from "veryfront/extensions";\nexport const marker = "kept";\n';
+    const testSource =
+      'import { BasicTracerProvider } from "npm:@opentelemetry/sdk-trace-base@2.9.0";\nexport const marker = "kept";\n';
+
+    for (
+      const extensionPath of [
+        "/repo/extensions/ext-yaml/src/adapter.ts",
+        String.raw`C:\repo\extensions\ext-yaml\src\adapter.ts`,
+      ]
+    ) {
+      assertEquals(bunPreloadRewriteFilter.test(extensionPath), true);
+      assertEquals(
+        rewriteBunPreloadSource(extensionPath, extensionSource, (source) =>
+          source.replace(
+            '"veryfront/extensions"',
+            '"../../../src/extensions/types.ts"',
+          )),
+        'import { defineExtension } from "../../../src/extensions/types.ts";\nexport const marker = "kept";\n',
+      );
+    }
+
+    for (
+      const testPath of [
+        "/repo/tests/bun/npm-protocol-resolution.test.ts",
+        String.raw`C:\repo\tests\bun\npm-protocol-resolution.test.ts`,
+        "/repo/extensions/fixtures/npm-protocol-resolution.test.ts",
+        String.raw`C:\repo\extensions\fixtures\npm-protocol-resolution.test.ts`,
+      ]
+    ) {
+      assertEquals(bunPreloadRewriteFilter.test(testPath), true);
+      assertEquals(
+        rewriteBunPreloadSource(testPath, testSource, () => {
+          throw new Error("test files must not use extension import rewriting");
+        }),
+        'import { BasicTracerProvider } from "@opentelemetry/sdk-trace-base";\nexport const marker = "kept";\n',
+      );
+    }
+  });
 });

tests/bun/preload-rewrite.ts

@@ -0,0 +1,27 @@
+import { rewriteNpmProtocolImports } from "./npm-protocol-imports.ts";
+
+export const bunPreloadRewriteFilter =
+  /(\.test\.[cm]?[jt]sx?|[/\\]extensions[/\\]ext-[^/\\]+[/\\]src[/\\].*\.[cm]?[jt]sx?)$/;
+
+function normalizePreloadPath(path: string): string {
+  return path.replaceAll("\\", "/");
+}
+
+function isExtensionSourcePath(path: string): boolean {
+  return /(?:^|\/)extensions\/ext-[^/]+\/src\/.*\.[cm]?[jt]sx?$/.test(path);
+}
+
+export function rewriteBunPreloadSource(
+  path: string,
+  source: string,
+  rewriteExtensionImports: (source: string) => string | null,
+): string {
+  const posixPath = normalizePreloadPath(path);
+  let contents = isExtensionSourcePath(posixPath)
+    ? rewriteExtensionImports(source) ?? source
+    : source;
+  if (/\.test\.[cm]?[jt]sx?$/.test(posixPath)) {
+    contents = rewriteNpmProtocolImports(contents) ?? contents;
+  }
+  return contents;
+}

tests/bun/preload.ts

@@ -12,7 +12,8 @@ import { plugin } from "bun";
 import { existsSync, readFileSync, statSync } from "fs";
 import { dirname, extname, relative, resolve, sep } from "path";
 import { fileURLToPath } from "url";
-import { rewriteModuleSpecifiers, rewriteNpmProtocolImports } from "./npm-protocol-imports.ts";
+import { rewriteModuleSpecifiers } from "./npm-protocol-imports.ts";
+import { bunPreloadRewriteFilter, rewriteBunPreloadSource } from "./preload-rewrite.ts";
 
 const projectRoot = resolve(import.meta.dir, "../..");
 
@@ -144,21 +145,19 @@ plugin({
     // import-looking fixture strings and comments untouched.
     build.onLoad(
       {
-        filter:
-          /(\.test\.[cm]?[jt]sx?|[/\\]extensions[/\\]ext-[^/\\]+[/\\]src[/\\].*\.[cm]?[jt]sx?)$/,
+        filter: bunPreloadRewriteFilter,
       },
       (args) => {
-        const posixPath = args.path.split(sep).join("/");
         const source = readFileSync(args.path, "utf8");
-        let contents = posixPath.includes("/extensions/")
-          ? rewriteModuleSpecifiers(
-            source,
-            (specifier) => workspaceModuleSpecifier(args.path, specifier),
-          ) ?? source
-          : source;
-        if (/\.test\.[cm]?[jt]sx?$/.test(posixPath)) {
-          contents = rewriteNpmProtocolImports(contents) ?? contents;
-        }
+        const contents = rewriteBunPreloadSource(
+          args.path,
+          source,
+          (extensionSource) =>
+            rewriteModuleSpecifiers(
+              extensionSource,
+              (specifier) => workspaceModuleSpecifier(args.path, specifier),
+            ),
+        );
         const extension = extname(args.path).toLowerCase();
         const loader = extension === ".tsx"
           ? "tsx"

tests/bun/runner-args.test.mjs

@@ -3,12 +3,15 @@ import { spawnSync } from "node:child_process";
 import { EventEmitter } from "node:events";
 import { readFileSync } from "node:fs";
 import test from "node:test";
+import { fileURLToPath } from "node:url";
 import {
   buildBunTestArgs,
   buildIsolatedBunTestRuns,
   registerBunWorkspaceCleanup,
 } from "./runner-args.mjs";
 
+const runTestsPath = fileURLToPath(new URL("./run-tests.mjs", import.meta.url));
+
 test("buildBunTestArgs caps concurrency without enabling concurrent test semantics", () => {
   const args = buildBunTestArgs(["one.test.ts", "two.test.ts"], 3);
 
@@ -50,7 +53,7 @@ test("the Bun runner drains child output and exits naturally", () => {
 test("the Bun runner fails loudly when filters select no files", () => {
   const result = spawnSync(
     process.execPath,
-    [new URL("./run-tests.mjs", import.meta.url).pathname],
+    [runTestsPath],
     {
       env: { ...process.env, BUN_TEST_INCLUDE: "missing-bun-fixture.test.ts" },
       encoding: "utf8",
@@ -62,6 +65,18 @@ test("the Bun runner fails loudly when filters select no files", () => {
   assert.doesNotMatch(result.stdout, /0 passed, 0 failed/);
 });
 
+test("the empty-selection spawn path is decoded through fileURLToPath", () => {
+  const source = readFileSync(fileURLToPath(import.meta.url), "utf8");
+  const runnerPathnameAccess = 'run-tests.mjs", import.meta.url)' +
+    ".pathname";
+
+  assert.match(
+    source,
+    /const runTestsPath = fileURLToPath\(new URL\("\.\/run-tests\.mjs", import\.meta\.url\)\)/,
+  );
+  assert.equal(source.includes(runnerPathnameAccess), false);
+});
+
 test("Bun workspace cleanup runs before termination signals are re-raised", () => {
   const runtimeProcess = new EventEmitter();
   runtimeProcess.pid = 123;

tests/bun/workspace-packages.mjs

@@ -1,31 +1,109 @@
-import { existsSync, mkdirSync, readFileSync, rmdirSync, rmSync, writeFileSync } from "node:fs";
+import {
+  existsSync,
+  mkdirSync,
+  readFileSync,
+  renameSync,
+  rmdirSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
 import { dirname, isAbsolute, join, relative, resolve, sep } from "node:path";
-import { randomUUID } from "node:crypto";
+import { createHash, randomUUID } from "node:crypto";
 import { ensureDirectoryLink } from "../ensure-npm-links.mjs";
 
 const MARKER_NAME = ".veryfront-bun-workspace-package.json";
 const LOCK_NAME = ".veryfront-bun-workspace-packages.lock";
+const RECLAIMER_GUARD_PREFIX = ".veryfront-bun-workspace-packages.reclaiming-";
 const LOCK_OWNER = "veryfront-bun-tests";
 
 function readJson(path) {
   return JSON.parse(readFileSync(path, "utf8"));
 }
 
+function activePreparationError() {
+  return new Error("Bun workspace package preparation is already active");
+}
+
+function waitForReclaimRaceTestBarrier() {
+  const barrierPath = process.env.VF_BUN_WORKSPACE_RECLAIM_BARRIER_PATH;
+  if (!barrierPath) return;
+  mkdirSync(barrierPath, { recursive: true });
+  writeFileSync(
+    join(barrierPath, `ready-${process.pid}-${randomUUID()}`),
+    "ready\n",
+    { flag: "wx" },
+  );
+  const releasePath = join(barrierPath, "release");
+  const deadline = Date.now() + 10_000;
+  const signal = new Int32Array(new SharedArrayBuffer(4));
+  while (!existsSync(releasePath)) {
+    if (Date.now() >= deadline) {
+      throw new Error("Timed out waiting for the Bun workspace reclaim barrier");
+    }
+    Atomics.wait(signal, 0, 0, 10);
+  }
+}
+
+function reclaimerGuardPath(nodeModulesPath, token) {
+  const digest = createHash("sha256").update(token).digest("hex");
+  return join(nodeModulesPath, `${RECLAIMER_GUARD_PREFIX}${digest}`);
+}
+
+function createPreparationLock(nodeModulesPath, lockPath, token) {
+  const stagingPath = join(
+    nodeModulesPath,
+    `${LOCK_NAME}.staging-${process.pid}-${token}`,
+  );
+  try {
+    mkdirSync(stagingPath);
+    writeFileSync(
+      join(stagingPath, MARKER_NAME),
+      `${JSON.stringify({ owner: LOCK_OWNER, pid: process.pid, token })}\n`,
+    );
+    if (process.env.VF_BUN_WORKSPACE_INTERRUPT_BEFORE_LOCK_PUBLISH === "1") {
+      process.exit(18);
+    }
+    if (existsSync(lockPath)) {
+      const conflict = new Error("Bun workspace package lock already exists");
+      conflict.code = "EEXIST";
+      throw conflict;
+    }
+    renameSync(stagingPath, lockPath);
+  } catch (error) {
+    rmSync(stagingPath, { recursive: true, force: true });
+    throw error;
+  }
+}
+
+export function isDirectoryPathConflict(error, path) {
+  return existsSync(path) &&
+    ["EACCES", "EEXIST", "ENOTEMPTY", "EPERM"].includes(error?.code);
+}
+
 function acquirePreparationLock(nodeModulesPath) {
   mkdirSync(nodeModulesPath, { recursive: true });
   const lockPath = join(nodeModulesPath, LOCK_NAME);
+  const token = randomUUID();
+  let reclaimedGuardPath;
   try {
-    mkdirSync(lockPath);
+    createPreparationLock(nodeModulesPath, lockPath, token);
   } catch (error) {
-    if (error?.code === "EEXIST") {
-      if (!reclaimStalePreparationLock(lockPath)) {
-        throw new Error("Bun workspace package preparation is already active");
+    if (isDirectoryPathConflict(error, lockPath)) {
+      reclaimedGuardPath = reclaimStalePreparationLock(
+        nodeModulesPath,
+        lockPath,
+      );
+      if (!reclaimedGuardPath) {
+        throw activePreparationError();
       }
       try {
-        mkdirSync(lockPath);
+        createPreparationLock(nodeModulesPath, lockPath, token);
       } catch (retryError) {
-        if (retryError?.code === "EEXIST") {
-          throw new Error("Bun workspace package preparation is already active");
+        if (isDirectoryPathConflict(retryError, lockPath)) {
+          // This generation tombstone must remain permanent. Otherwise an
+          // arbitrarily delayed stale-generation reader could reuse it after a
+          // fresh runner acquires lockPath and move that fresh live lock.
+          throw activePreparationError();
         }
         throw retryError;
       }
@@ -34,41 +112,70 @@ function acquirePreparationLock(nodeModulesPath) {
     }
   }
 
-  const token = randomUUID();
-  try {
-    writeFileSync(
-      join(lockPath, MARKER_NAME),
-      `${JSON.stringify({ owner: LOCK_OWNER, pid: process.pid, token })}\n`,
-    );
-  } catch (error) {
-    rmSync(lockPath, { recursive: true, force: true });
-    throw error;
-  }
-
   return { lockPath, token };
 }
 
-export function reclaimStalePreparationLock(lockPath, runtimeProcess = process) {
+function isOwnedLockMarker(marker) {
+  return marker?.owner === LOCK_OWNER &&
+    Number.isSafeInteger(marker.pid) &&
+    marker.pid >= 1 &&
+    typeof marker.token === "string" &&
+    marker.token.length > 0;
+}
+
+function sameLockGeneration(left, right) {
+  return left?.owner === right?.owner &&
+    left?.pid === right?.pid &&
+    left?.token === right?.token;
+}
+
+function reclaimStalePreparationLock(
+  nodeModulesPath,
+  lockPath,
+  runtimeProcess = process,
+) {
   let marker;
   try {
     marker = readJson(join(lockPath, MARKER_NAME));
   } catch {
     return false;
   }
 
-  if (marker?.owner !== LOCK_OWNER) {
-    return false;
-  }
-  if (!Number.isSafeInteger(marker.pid) || marker.pid < 1) {
+  if (!isOwnedLockMarker(marker)) {
     return false;
   }
   try {
     runtimeProcess.kill(marker.pid, 0);
     return false;
   } catch (error) {
     if (error?.code !== "ESRCH") return false;
-    rmSync(lockPath, { recursive: true, force: true });
-    return true;
+    waitForReclaimRaceTestBarrier();
+    const guardPath = reclaimerGuardPath(nodeModulesPath, marker.token);
+    try {
+      renameSync(lockPath, guardPath);
+    } catch (renameError) {
+      if (
+        renameError?.code === "ENOENT" ||
+        isDirectoryPathConflict(renameError, guardPath)
+      ) {
+        return false;
+      }
+      throw renameError;
+    }
+
+    let claimedMarker;
+    try {
+      claimedMarker = readJson(join(guardPath, MARKER_NAME));
+    } catch {
+      return false;
+    }
+    if (!sameLockGeneration(marker, claimedMarker)) {
+      return false;
+    }
+    // Lock markers are immutable after publication. Matching the generation
+    // after the atomic rename proves this process claimed the stale directory;
+    // keep that path as a permanent tombstone for delayed readers.
+    return guardPath;
   }
 }