Fix: support Yarn PnP SDK prettierPath entry file (#3911) (#3914)

* Fix Yarn PnP SDK module resolution when prettierPath points to a file

When `prettier.prettierPath` is set to a file path like
`.yarn/sdks/prettier/index.cjs` (common in Yarn PnP SDK setups),
the extension incorrectly treated it as a directory and tried to
read `index.cjs/package.json`, causing module loading to fail.

This fix:
- In `ModuleResolverNode.ts`: Check if the path is a file and use
  the parent directory to find `package.json`
- In `PrettierDynamicInstance.ts`: Detect `.js/.cjs/.mjs` file
  extensions and use the file directly instead of resolving

Fixes the error:
"Failed to load module... index.cjs/package.json"

* Add test for Yarn PnP SDK prettierPath file resolution

Add test fixture and test case to verify that the extension correctly
handles `prettierPath` pointing to a `.cjs` file, which is common in
Yarn PnP SDK setups.

Test fixture structure:
- `.yarn/sdks/prettier/index.cjs` - SDK wrapper entry point
- `.vscode/settings.json` - with prettierPath pointing to the .cjs file

* Refactor comment for clarity on modulePath usage

---------

Co-authored-by: 이준영 <54898597+ff1451@users.noreply.github.com>

Author: ntotten

CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to the "prettier-vscode" extension will be documented in thi
 
 ## [Unreleased]
 
+- Fixed module resolution when `prettierPath` points to a file (e.g., `.yarn/sdks/prettier/index.cjs` in Yarn PnP SDK setups)
+
 ## [12.1.0]
 
 - [BREAKING CHANGE] Bundled Prettier upgraded from v2.8.8 to v3.x

src/ModuleResolverNode.ts

@@ -329,7 +329,19 @@ export class ModuleResolver implements ModuleResolverInterface {
     let modulePackageJsonPath = "";
 
     try {
-      modulePackageJsonPath = path.join(modulePath, "package.json");
+      // Check if modulePath is a file or directory
+      // If it's a file (e.g., .yarn/sdks/prettier/index.cjs), look for package.json in parent directory
+      let packageDir = modulePath;
+      try {
+        const stat = await fs.promises.stat(modulePath);
+        if (stat.isFile()) {
+          packageDir = path.dirname(modulePath);
+        }
+      } catch {
+        // If stat fails, assume it's a directory path
+      }
+
+      modulePackageJsonPath = path.join(packageDir, "package.json");
       const rawPkgJson = await fs.promises.readFile(modulePackageJsonPath, {
         encoding: "utf8",
       });

src/PrettierDynamicInstance.ts

@@ -22,12 +22,22 @@ export const PrettierDynamicInstance: PrettierInstanceConstructor = class Pretti
   constructor(private modulePath: string) {}
 
   public async import(): Promise</* version of imported prettier */ string> {
-    // Resolve to actual entry file since ESM doesn't support directory imports
-    // modulePath is like /path/to/node_modules/prettier, resolve "prettier" from there
-    const entryPath = resolveModuleEntry(
-      this.modulePath,
-      path.basename(this.modulePath),
-    );
+    // Check if modulePath is a file or directory
+    // If it's a file (e.g., .yarn/sdks/prettier/index.cjs), use it directly
+    // If it's a directory (e.g., node_modules/prettier), resolve the entry
+    let entryPath: string;
+    const ext = path.extname(this.modulePath).toLowerCase();
+    if (ext === ".js" || ext === ".cjs" || ext === ".mjs") {
+      // modulePath is a file, use it
+      entryPath = this.modulePath;
+    } else {
+      // Resolve to actual entry file since ESM doesn't support directory imports
+      // modulePath is like /path/to/node_modules/prettier, resolve "prettier" from there
+      entryPath = resolveModuleEntry(
+        this.modulePath,
+        path.basename(this.modulePath),
+      );
+    }
     const moduleUrl = pathToFileURL(entryPath).href;
     const imported = await import(moduleUrl);
     // Handle both ESM (Prettier v3+) and CJS (Prettier v2) modules

src/test/suite/yarn-pnp-sdk.test.ts

@@ -0,0 +1,15 @@
+import * as assert from "assert";
+import { format, getText } from "./formatTestUtils.js";
+import { ensureExtensionActivated } from "./testUtils.js";
+
+describe("Test Yarn PnP SDK with prettierPath pointing to .cjs file", () => {
+  before(async () => {
+    await ensureExtensionActivated();
+  });
+
+  it("it formats with prettierPath pointing to a .cjs file", async () => {
+    const { actual } = await format("yarn-pnp-sdk", "index.js");
+    const expected = await getText("yarn-pnp-sdk", "index.result.js");
+    assert.equal(actual, expected);
+  });
+});

test-fixtures/test.code-workspace

@@ -65,6 +65,9 @@
     },
     {
       "path": "monorepo-subfolder"
+    },
+    {
+      "path": "yarn-pnp-sdk"
     }
   ],
   "settings": {

test-fixtures/yarn-pnp-sdk/.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "prettier.prettierPath": ".yarn/sdks/prettier/index.cjs"
+}

test-fixtures/yarn-pnp-sdk/.yarn/sdks/prettier/index.cjs

@@ -0,0 +1,8 @@
+#!/usr/bin/env node
+
+// Simulates Yarn PnP SDK wrapper for Prettier
+// This file is the entry point when prettierPath points to a .cjs file
+
+const prettier = require("prettier");
+
+module.exports = prettier;

test-fixtures/yarn-pnp-sdk/.yarn/sdks/prettier/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "prettier",
+  "version": "3.4.2",
+  "main": "./index.cjs"
+}

test-fixtures/yarn-pnp-sdk/index.js

@@ -0,0 +1 @@
+const x={a:1,b:2,c:3}

test-fixtures/yarn-pnp-sdk/index.result.js

@@ -0,0 +1 @@
+const x = { a: 1, b: 2, c: 3 };