fix: Match promisified fs.read call return with original implementati…

…on (#2128)

* fix: Match promisified fs.read call return with original implementation

* chore: Updated versions

* test: Validate promisified fs.read matches correct return shape

* chore: Updated hook

.yarn/versions/457322f8.yml

@@ -0,0 +1,35 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/fslib": patch
+  "@yarnpkg/plugin-pnp": patch
+  "@yarnpkg/pnp": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-exec"
+  - "@yarnpkg/plugin-file"
+  - "@yarnpkg/plugin-git"
+  - "@yarnpkg/plugin-github"
+  - "@yarnpkg/plugin-http"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-node-modules"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - vscode-zipfs
+  - "@yarnpkg/builder"
+  - "@yarnpkg/core"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/json-proxy"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/shell"

packages/yarnpkg-fslib/sources/index.ts

@@ -137,6 +137,7 @@ export function patchFs(patchedFs: typeof fs, fakeFs: FakeFS<NativePath>): void
     const orig = target[name];
     target[name] = replacement;
 
+    // Preserve any util.promisify implementations
     if (typeof orig?.[promisify.custom] !== `undefined`) {
       replacement[promisify.custom] = orig[promisify.custom];
     }
@@ -284,6 +285,19 @@ export function patchFs(patchedFs: typeof fs, fakeFs: FakeFS<NativePath>): void
       // `fs.promises.realpath` doesn't have a `native` property
     }
   }
+
+  /** util.promisify implementations */
+  {
+    // Override the promisified version of `fs.read` to return an object as per
+    // https://github.com/nodejs/node/blob/dc79f3f37caf6f25b8efee4623bec31e2c20f595/lib/fs.js#L559-L560
+    // and
+    // https://github.com/nodejs/node/blob/ba684805b6c0eded76e5cd89ee00328ac7a59365/lib/internal/util.js#L293
+    // @ts-expect-error
+    patchedFs.read[promisify.custom] = async (p: number, buffer: Buffer, ...args: Array<any>) => {
+      const res = fakeFs.readPromise(p, buffer, ...args);
+      return {bytesRead: await res, buffer};
+    };
+  }
 }
 
 export function extendFs(realFs: typeof fs, fakeFs: FakeFS<NativePath>): typeof fs {

packages/yarnpkg-fslib/tests/patchedFs.test.ts

@@ -1,4 +1,5 @@
 import fs                       from 'fs';
+import {promisify}              from 'util';
 
 import {NodeFS}                 from '../sources/NodeFS';
 import {PosixFS}                from '../sources/PosixFS';
@@ -39,4 +40,20 @@ describe(`patchedFs`, () => {
       done();
     });
   });
+
+  it(`matches the util.promisify return shape of node: fs.read`, async () => {
+    const patchedFs = extendFs(fs, new PosixFS(new NodeFS()));
+    const patchedFsReadAsync = promisify(patchedFs.read);
+
+    const file = ppath.join(npath.toPortablePath(__dirname), `patchedFs.test.ts` as Filename);
+
+    const fd = fs.openSync(file, `r`);
+
+    const bufferFs = Buffer.alloc(16);
+
+    const result = await patchedFsReadAsync(fd, bufferFs, 0, 16, 0);
+
+    expect(typeof result.bytesRead).toBe(`number`);
+    expect(Buffer.isBuffer(result.buffer)).toBeTruthy();
+  });
 });