fix(fslib): fix return shape of promisified fs.write (#4411)

* fix(fslib): fix return shape of promisified `fs.write`

* chore: update hook

* chore: versions

Co-authored-by: merceyz <merceyz@users.noreply.github.com>

.yarn/versions/7e1696fd.yml

@@ -0,0 +1,38 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/fslib": patch
+  "@yarnpkg/plugin-pnp": patch
+  "@yarnpkg/pnp": patch
+  "@yarnpkg/pnpify": patch
+
+declined:
+  - "@yarnpkg/esbuild-plugin-pnp"
+  - "@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-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnpm"
+  - "@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/nm"
+  - "@yarnpkg/sdks"
+  - "@yarnpkg/shell"

packages/yarnpkg-fslib/sources/patchFs.ts

@@ -363,15 +363,23 @@ export function patchFs(patchedFs: typeof fs, fakeFs: FakeFS<NativePath>): void
 
   /** util.promisify implementations */
   {
-    // Override the promisified version of `fs.read` to return an object as per
+    // TODO add promisified `fs.readv` and `fs.writev`, once they are implemented
+    // Override the promisified versions of `fs.read` and `fs.write` 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/dc79f3f37caf6f25b8efee4623bec31e2c20f595/lib/fs.js#L690-L691
+    // 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);
+    patchedFs.read[promisify.custom] = async (fd: number, buffer: Buffer, ...args: Array<any>) => {
+      const res = fakeFs.readPromise(fd, buffer, ...args);
       return {bytesRead: await res, buffer};
     };
+    // @ts-expect-error
+    patchedFs.write[promisify.custom] = async (fd: number, buffer: Buffer, ...args: Array<any>) => {
+      const res = fakeFs.writePromise(fd, buffer, ...args);
+      return {bytesWritten: await res, buffer};
+    };
   }
 }
 

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

@@ -63,6 +63,24 @@ describe(`patchedFs`, () => {
     expect(Buffer.isBuffer(result.buffer)).toBeTruthy();
   });
 
+  it(`matches the util.promisify return shape of node: fs.write`, async () => {
+    const patchedFs = extendFs(fs, new PosixFS(new NodeFS()));
+    const patchedFsWriteAsync = promisify(patchedFs.write);
+
+    const tmpdir = npath.fromPortablePath(xfs.mktempSync());
+
+    const file = npath.join(tmpdir, `file.txt`);
+
+    const fd = fs.openSync(file, `w`);
+
+    const bufferFs = Buffer.alloc(16);
+
+    const result = await patchedFsWriteAsync(fd, bufferFs, 0, 16, 0);
+
+    expect(typeof result.bytesWritten).toBe(`number`);
+    expect(Buffer.isBuffer(result.buffer)).toBeTruthy();
+  });
+
   it(`should support URL instances`, () => {
     const patchedFs = extendFs(fs, new PosixFS(new NodeFS()));