feat: add version_file_path option

Using the same logic as `actions/setup-node`, we can support `asdf`, `volta` or other version management techniques.

.github/workflows/test.yaml

@@ -35,6 +35,122 @@ jobs:
       - name: 'Test: install'
         run: pnpm install
 
+  test_version_file_asdf:
+    name: Test with version file (asdf)
+
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        pnpm:
+          - 4.11.1
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run the action
+        uses: ./
+        with:
+          version_file_path: test/.tool-versions
+
+      - name: 'Test: which'
+        run: which pnpm; which pnpx
+
+      - name: 'Test: install'
+        run: pnpm install
+
+  test_version_file_engines:
+    name: Test with version file (package.json engines)
+
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        pnpm:
+          - 4.11.1
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run the action
+        uses: ./
+        with:
+          version_file_path: test/package.engines.json
+
+      - name: 'Test: which'
+        run: which pnpm; which pnpx
+
+      - name: 'Test: install'
+        run: pnpm install
+
+  test_version_file_volta:
+    name: Test with version file (volta)
+
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        pnpm:
+          - 4.11.1
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run the action
+        uses: ./
+        with:
+          version_file_path: test/package.volta.json
+
+      - name: 'Test: which'
+        run: which pnpm; which pnpx
+
+      - name: 'Test: install'
+        run: pnpm install
+
+  test_version_file_volta_extends:
+    name: Test with version file (volta extends)
+
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        pnpm:
+          - 4.11.1
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run the action
+        uses: ./
+        with:
+          version_file_path: test/package.volta-extends.json
+
+      - name: 'Test: which'
+        run: which pnpm; which pnpx
+
+      - name: 'Test: install'
+        run: pnpm install
+
   test_dest:
     name: Test with dest
 

README.md

@@ -16,6 +16,12 @@ Version of pnpm to install.
 
 otherwise, this field is **required** It supports npm versioning scheme, it could be an exact version (such as `6.24.1`), or a version range (such as `6`, `6.x.x`, `6.24.x`, `^6.24.1`, `*`, etc.), or `latest`.
 
+### `version_file_path`
+
+The `version_file_path` input accepts a path to a file containing the version of pnpm to be used. For example `.tool-versions` (if you use `asdf`), or package.json (if you use the engines property or [`volta`](https://volta.sh) instead of corepack).
+
+The action will search for the version file relative to the repository root.
+
 ### `dest`
 
 **Optional** Where to store pnpm files.
@@ -83,6 +89,26 @@ jobs:
           version: 9
 ```
 
+### Install only pnpm with a version file
+
+This works when you use `volta`, `asdf`, etc.
+
+```yaml
+on:
+  - push
+  - pull_request
+
+jobs:
+  install:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: pnpm/action-setup@v4
+        with:
+          version_file_path: ".tool-versions" # with asdf
+          # version_file_path: "package.json" # with volta
+```
+
 ###  Install only pnpm with `packageManager`
 
 Omit `version` input to use the version in the [`packageManager` field in the `package.json`](https://nodejs.org/api/corepack.html).

action.yml

@@ -7,6 +7,9 @@ inputs:
   version:
     description: Version of pnpm to install
     required: false
+  version_file_path:
+    description: "Path to a version file. Eg: '.tool-versions' for asdf or 'package.json' for volta"
+    required: false
   dest:
     description: Where to store pnpm files
     required: false

src/inputs/index.ts

@@ -4,6 +4,7 @@ import { RunInstall, parseRunInstall } from './run-install'
 
 export interface Inputs {
   readonly version?: string
+  readonly versionFilePath?: string
   readonly dest: string
   readonly runInstall: RunInstall[]
   readonly packageJsonFile: string
@@ -18,6 +19,7 @@ const parseInputPath = (name: string) => expandTilde(getInput(name, options))
 
 export const getInputs = (): Inputs => ({
   version: getInput('version'),
+  versionFilePath: getInput('version_file_path'),
   dest: parseInputPath('dest'),
   runInstall: parseRunInstall('run_install'),
   packageJsonFile: parseInputPath('package_json_file'),

src/install-pnpm/run.ts

@@ -1,14 +1,14 @@
 import { addPath, exportVariable } from '@actions/core'
 import { spawn } from 'child_process'
 import { rm, writeFile, mkdir } from 'fs/promises'
-import { readFileSync } from 'fs'
+import { readFileSync, existsSync } from 'fs'
 import path from 'path'
 import { execPath } from 'process'
 import util from 'util'
 import { Inputs } from '../inputs'
 
 export async function runSelfInstaller(inputs: Inputs): Promise<number> {
-  const { version, dest, packageJsonFile, standalone } = inputs
+  const { version, versionFilePath, dest, packageJsonFile, standalone } = inputs
 
   // prepare self install
   await rm(dest, { recursive: true, force: true })
@@ -19,7 +19,7 @@ export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   await writeFile(pkgJson, JSON.stringify({ private: true }))
 
   // prepare target pnpm
-  const target = await readTarget({ version, packageJsonFile, standalone })
+  const target = await readTarget({ version, versionFilePath, packageJsonFile, standalone })
   const cp = spawn(execPath, [path.join(__dirname, 'pnpm.cjs'), 'install', target, '--no-lockfile'], {
     cwd: dest,
     stdio: ['pipe', 'inherit', 'inherit'],
@@ -37,12 +37,71 @@ export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   return exitCode
 }
 
+// Nearly identical to the function `actions/setup-node` uses.
+// See https://github.com/actions/setup-node/blob/39370e3970a6d050c480ffad4ff0ed4d3fdee5af/src/util.ts#L8
+function getPnpmVersionFromFile(versionFilePath: string) {
+  if (!existsSync(versionFilePath)) {
+    throw new Error(
+      `The specified pnpm version file at: ${versionFilePath} does not exist`
+    )
+  }
+
+  const contents = readFileSync(versionFilePath, 'utf8')
+
+  // Try parsing the file as a `package.json` file.
+  try {
+    const manifest = JSON.parse(contents)
+
+    // Presume package.json file.
+    if (typeof manifest === 'object' && !!manifest) {
+      // Support Volta.
+      // See https://docs.volta.sh/guide/understanding#managing-your-project
+      if (manifest.volta?.pnpm) {
+        return manifest.volta.pnpm as string
+      }
+
+      if (manifest.engines?.pnpm) {
+        return manifest.engines.pnpm as string
+      }
+
+      // Support Volta workspaces.
+      // See https://docs.volta.sh/advanced/workspaces
+      if (manifest.volta?.extends) {
+        const extendedFilePath = path.resolve(
+          path.dirname(versionFilePath),
+          manifest.volta.extends
+        )
+        console.info('Resolving pnpm version from ' + extendedFilePath)
+        return getPnpmVersionFromFile(extendedFilePath)
+      }
+
+      // If contents are an object, we parsed JSON
+      // this can happen if pnpm-version-file is a package.json
+      // yet contains no volta.pnpm or engines.pnpm
+      //
+      // If pnpm-version file is _not_ JSON, control flow
+      // will not have reached these lines.
+      //
+      // And because we've reached here, we know the contents
+      // *are* JSON, so no further string parsing makes sense.
+      return
+    }
+  } catch {
+    console.info('pnpm version file is not JSON file')
+  }
+
+  const found = contents.match(/^(?:pnpm\s+)?v?(?<version>[^\s]+)$/m)
+  return found?.groups?.version ?? contents.trim()
+}
+
 async function readTarget(opts: {
   readonly version?: string | undefined
+  readonly versionFilePath?: string | undefined
   readonly packageJsonFile: string
   readonly standalone: boolean
 }) {
-  const { version, packageJsonFile, standalone } = opts
+  const { versionFilePath, packageJsonFile, standalone } = opts
+  let { version } = opts
   const { GITHUB_WORKSPACE } = process.env
 
   let packageManager
@@ -56,6 +115,14 @@ async function readTarget(opts: {
     }
   }
 
+  if (typeof versionFilePath === "string" && typeof version === "string") {
+    throw new Error("Multiple version determination methods specified: 'version' and 'version_file_path'. Please specify only one.")
+  }
+
+  if (versionFilePath) {
+    version = getPnpmVersionFromFile(versionFilePath)
+  }
+
   if (version) {
     if (
       typeof packageManager === 'string' &&

test/.tool-versions

@@ -0,0 +1 @@
+pnpm 4.11.1

test/package.engines.json

@@ -0,0 +1 @@
+{"engines":{"pnpm":"4.11.1"}}

test/package.volta-extends.json

@@ -0,0 +1 @@
+{"volta":{"extends":"./package.volta.json"}}

test/package.volta.json

@@ -0,0 +1 @@
+{"volta":{"pnpm":"4.11.1"}}