perf(core): skip unnecessary exists checks (#3963)

Author: merceyz

.yarn/versions/c608964d.yml

@@ -0,0 +1,33 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/core": 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-nm"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/nm"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/sdks"

packages/yarnpkg-core/sources/Manifest.ts

@@ -96,10 +96,14 @@ export class Manifest {
   static async tryFind(path: PortablePath, {baseFs = new NodeFS()}: {baseFs?: FakeFS<PortablePath>} = {}) {
     const manifestPath = ppath.join(path, `package.json` as Filename);
 
-    if (!await baseFs.existsPromise(manifestPath))
-      return null;
+    try {
+      return await Manifest.fromFile(manifestPath, {baseFs});
+    } catch (err) {
+      if (err.code === `ENOENT`)
+        return null;
 
-    return await Manifest.fromFile(manifestPath, {baseFs});
+      throw err;
+    }
   }
 
   static async find(path: PortablePath, {baseFs}: {baseFs?: FakeFS<PortablePath>} = {}) {

packages/yarnpkg-core/sources/Workspace.ts

@@ -41,9 +41,7 @@ export class Workspace {
 
   async setup() {
     // @ts-expect-error: It's ok to initialize it now
-    this.manifest = xfs.existsSync(ppath.join(this.cwd, Manifest.fileName))
-      ? await Manifest.find(this.cwd)
-      : new Manifest();
+    this.manifest = await Manifest.tryFind(this.cwd) ?? new Manifest();
 
     // We use ppath.relative to guarantee that the default hash will be consistent even if the project is installed on different OS / path
     // @ts-expect-error: It's ok to initialize it now, even if it's readonly (setup is called right after construction)