fix(metro-config): fix duplicate packages slipping through

Author: tido64

.changeset/shaggy-dragons-fry.md

@@ -0,0 +1,5 @@
+---
+"@rnx-kit/metro-config": patch
+---
+
+Fix duplicate packages slipping through in a Yarn + pnpm setup

packages/metro-config/src/index.js

@@ -63,6 +63,30 @@ function defaultWatchFolders() {
   }
 }
 
+/**
+ * Extracts unique parts from a Yarn store directory.
+ * @param {string} p
+ * @returns {[string, string]}
+ */
+function extractUniquePartsFromYarnStoreDir(p) {
+  const parts = p.split("-");
+  const length = parts.length;
+
+  // Example: node_modules/.store/react-native-virtual-3e97acc5aa
+  if (parts[length - 2] === "virtual") {
+    return [parts.slice(0, length - 1).join("-"), parts.slice(-1).join("-")];
+  }
+
+  // Example: node_modules/.store/@react-native-assets-registry-npm-0.81.0-rc.5-d313abaf5e
+  const index = parts.lastIndexOf("npm");
+  if (index > 0) {
+    const pos = index + 1;
+    return [parts.slice(0, pos).join("-"), parts.slice(pos).join("-")];
+  }
+
+  throw new Error(`Failed to parse Yarn store directory: ${p}`);
+}
+
 /**
  * Returns the path to specified module; `undefined` if not found.
  *
@@ -107,14 +131,10 @@ function resolveUniqueModule(packageName, searchStartDir) {
   // - react-native -> node_modules/.store/react-native-virtual-3e97acc5aa/package
   if (path.basename(result) === "package" && result.includes(".store")) {
     const storePath = path.dirname(result);
-    const hashIndex = storePath.lastIndexOf("-") + 1;
-    const hashPart = storePath.substring(hashIndex);
-    const parent = path
-      .normalize(storePath.substring(0, hashIndex))
-      .replaceAll("\\", "\\\\")
-      .replaceAll(".", "\\.");
+    const [pre, unique] = extractUniquePartsFromYarnStoreDir(storePath);
+    const preEscaped = pre.replaceAll("\\", "\\\\").replaceAll(".", "\\.");
     const exclusionRE = new RegExp(
-      `${parent}\\w+(?<!${hashPart})\\${path.sep}package\\${path.sep}.*`
+      `${preEscaped}-[-.\\w]+(?<!${unique})\\${path.sep}package\\${path.sep}.*`
     );
     return [result, exclusionRE];
   }
@@ -278,6 +298,7 @@ module.exports = {
   defaultWatchFolders,
   excludeExtraCopiesOf,
   exclusionList,
+  extractUniquePartsFromYarnStoreDir,
   resolveUniqueModule,
 
   /**

packages/metro-config/test/index.test.ts

@@ -6,6 +6,7 @@ import { enhanceMiddleware } from "../src/assetPluginForMonorepos";
 import {
   defaultWatchFolders,
   exclusionList,
+  extractUniquePartsFromYarnStoreDir,
   makeMetroConfig,
   resolveUniqueModule,
 } from "../src/index";
@@ -55,6 +56,35 @@ describe("defaultWatchFolders()", () => {
   });
 });
 
+describe("extractUniquePartsFromYarnStoreDir()", () => {
+  it("returns version+hash from a versioned path", () => {
+    const [pre, unique] = extractUniquePartsFromYarnStoreDir(
+      "node_modules/.store/@babel-core-npm-7.27.1-0f1bf48e52"
+    );
+
+    equal(pre, "node_modules/.store/@babel-core-npm");
+    equal(unique, "7.27.1-0f1bf48e52");
+  });
+
+  it("returns version+hash from a path with prerelease number", () => {
+    const [pre, unique] = extractUniquePartsFromYarnStoreDir(
+      "node_modules/.store/@react-native-assets-registry-npm-0.81.0-rc.5-d313abaf5e"
+    );
+
+    equal(pre, "node_modules/.store/@react-native-assets-registry-npm");
+    equal(unique, "0.81.0-rc.5-d313abaf5e");
+  });
+
+  it("returns hash from a virtual path", () => {
+    const [pre, unique] = extractUniquePartsFromYarnStoreDir(
+      "node_modules/.store/react-native-virtual-3e97acc5aa"
+    );
+
+    equal(pre, "node_modules/.store/react-native-virtual");
+    equal(unique, "3e97acc5aa");
+  });
+});
+
 describe("resolveUniqueModule()", () => {
   afterEach(() => process.chdir(currentWorkingDir));