test: switch main project to node-modules linker, add pnpm-compat sub-project

Yarn 4 changed the pnpm linker's .store subdirectory name to 'package/'
(was the package name in yarn 3), breaking path-based hook detection.

Switch the main project to nodeLinker: node-modules to avoid the issue,
and add test/pnpm-compat/ as a minimal independent yarn sub-project with
nodeLinker: pnpm to specifically test the pnpm linker path format support.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dividedmind

.github/workflows/ci.yml

@@ -43,6 +43,12 @@ jobs:
           node-version: ${{matrix.node-version}}
           cache: yarn
       - run: yarn
+      - uses: actions/cache@v4
+        with:
+          path: |
+            test/pnpm-compat/.yarn/cache
+            test/pnpm-compat/.yarn/global
+          key: pnpm-compat-yarn-${{ runner.os }}-${{ hashFiles('test/pnpm-compat/yarn.lock') }}
       - run: node test/smoketest.mjs
       - run: yarn test
         env:
@@ -57,6 +63,12 @@ jobs:
         with:
           cache: yarn
       - run: yarn
+      - uses: actions/cache@v4
+        with:
+          path: |
+            test/pnpm-compat/.yarn/cache
+            test/pnpm-compat/.yarn/global
+          key: pnpm-compat-yarn-${{ runner.os }}-${{ hashFiles('test/pnpm-compat/yarn.lock') }}
       - run: yarn prepack
       - run: yarn test || yarn jest --no-silent --verbose --onlyFailures
       - run: node test/smoketest.mjs

.yarnrc.yml

@@ -2,7 +2,7 @@ compressionLevel: mixed
 
 enableGlobalCache: true
 
-nodeLinker: pnpm
+nodeLinker: node-modules
 
 npmMinimalAgeGate: 2880
 

test/__snapshots__/next16.test.ts.snap

@@ -192,7 +192,7 @@ exports[`mapping a Next.js 16 appmap 1`] = `
         "http_server_response": {
           "headers": {
             "Cache-Control": "no-store, must-revalidate",
-            "Content-Length": "2238",
+            "Content-Length": "2210",
             "Content-Type": "text/html; charset=utf-8",
             "Vary": "Accept-Encoding",
             "X-Powered-By": "Next.js",

test/next.test.ts

@@ -1,14 +1,19 @@
 import { IncomingMessage, request } from "node:http";
+import { resolve } from "node:path";
 
 import { getFreePort, integrationTest, readAppmaps, spawnAppmapNode } from "./helpers";
 
+const nextBin = require.resolve("next/dist/bin/next", {
+  paths: [resolve(__dirname, "next")],
+});
+
 async function spawnNextJsApp(port: number) {
   // On Windows, we give "node" argument explicitly because next is a js file with
   // shebang (#!/usr/bin/env node) which does not work on Windows.
   const app =
     process.platform == "win32"
-      ? spawnAppmapNode("node", "node_modules\\next\\dist\\bin\\next", "dev", "-p", String(port))
-      : spawnAppmapNode("node_modules/next/dist/bin/next", "dev", "-p", String(port));
+      ? spawnAppmapNode("node", nextBin, "dev", "-p", String(port))
+      : spawnAppmapNode(nextBin, "dev", "-p", String(port));
 
   await new Promise<void>((r) => {
     const onData = (chunk: Buffer) => {

test/next16.test.ts

@@ -1,16 +1,21 @@
 import { IncomingMessage, request } from "node:http";
+import { resolve } from "node:path";
 
 import { getFreePort, integrationTest, readAppmaps, spawnAppmapNode } from "./helpers";
 
+const nextBin = require.resolve("next/dist/bin/next", {
+  paths: [resolve(__dirname, "next16")],
+});
+
 async function spawnNextJsApp(port: number) {
   // On Windows, we give "node" argument explicitly because next is a js file with
   // shebang (#!/usr/bin/env node) which does not work on Windows.
   // Turbopack (the default bundler in Next.js 16) respects webpack loaders configured
   // via next.config turbopack.rules, which we inject in src/hooks/next.ts.
   const app =
     process.platform == "win32"
-      ? spawnAppmapNode("node", "node_modules\\next\\dist\\bin\\next", "dev", "-p", String(port))
-      : spawnAppmapNode("node_modules/next/dist/bin/next", "dev", "-p", String(port));
+      ? spawnAppmapNode("node", nextBin, "dev", "-p", String(port))
+      : spawnAppmapNode(nextBin, "dev", "-p", String(port));
 
   await new Promise<void>((r) => {
     const onData = (chunk: Buffer) => {

test/pnpm-compat.test.ts

@@ -0,0 +1,18 @@
+import { spawnSync } from "node:child_process";
+import { existsSync } from "node:fs";
+import { resolve } from "node:path";
+
+import { integrationTest, readAppmaps, runAppmapNode } from "./helpers";
+
+// This test runs vitest in a separate project installed with yarn pnpm linker,
+// verifying that matchesPackageFile() correctly identifies hook targets in the
+// .store/pkg-npm-version-hash/package/ path format used by yarn 4 pnpm linker.
+
+integrationTest("pnpm linker: vitest hooks instrument code in .store paths", () => {
+  const dir = resolve(__dirname, "pnpm-compat");
+  if (!existsSync(resolve(dir, "node_modules")))
+    spawnSync("yarn", ["install"], { cwd: dir, stdio: "inherit" });
+
+  expect(runAppmapNode("yarn", "vitest", "run").status).toBe(0);
+  expect(readAppmaps()).not.toEqual({});
+});

test/pnpm-compat/.gitignore

@@ -0,0 +1 @@
+.yarn/

test/pnpm-compat/.yarnrc.yml

@@ -0,0 +1,9 @@
+nodeLinker: pnpm
+
+enableGlobalCache: false
+
+cacheFolder: ./.yarn/cache
+
+globalFolder: ./.yarn/global
+
+yarnPath: ../../.yarn/releases/yarn-4.13.0.cjs

test/pnpm-compat/appmap.yml

@@ -0,0 +1,4 @@
+name: pnpm-compat-appmap-node-test
+packages:
+  - path: .
+language: javascript

test/pnpm-compat/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "pnpm-compat-appmap-node-test",
+  "private": true,
+  "dependencies": {
+    "vitest": "^0.34.6"
+  }
+}