docs: clarify manifest-based version selection (#244)

* updating readme to include devEngines.packageManager.version in selecting version

* docs: check out the manifest before inferring pnpm version

---------

Co-authored-by: Zoltan Kochan <z@kochan.io>

.github/workflows/pr-check.yaml

@@ -13,10 +13,10 @@ jobs:
   check-dist:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5.0.0
+        uses: pnpm/action-setup@ea17c68df8912ef543352723c149a84f56e3d413 # v6.1.0
         with:
           run_install: true
           version: 11

.github/workflows/test.yaml

@@ -51,7 +51,7 @@ jobs:
             version: '12.3.4'
 
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - id: pnpm
         name: Run the action
@@ -134,7 +134,7 @@ jobs:
             expect_pm_on_fail_unset: true
 
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Set up package.json
         run: echo '${{ matrix.manifest }}' > package.json
@@ -183,7 +183,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
@@ -234,7 +234,7 @@ jobs:
     env:
       REQUIRED: ${{ matrix.version }}
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
@@ -298,7 +298,7 @@ jobs:
     name: 'Standalone Windows self-update (PATH regression)'
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Set up package.json with a minimal manifest
         # run_install needs a manifest to install against. Removing the
@@ -356,7 +356,7 @@ jobs:
             manifest: '{"devEngines":{"packageManager":{"name":"pnpm","version":">=10 <11"}},"dependencies":{"is-odd":"3.0.1"}}'
 
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Set up package.json
         run: echo '${{ matrix.manifest }}' > package.json
@@ -400,7 +400,7 @@ jobs:
                 - yarn
 
     steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Run the action
         uses: ./

README.md

@@ -64,7 +64,7 @@ Input and output changes:
 
 Version of pnpm to install.
 
-**Optional** when there is a [`packageManager` or `devEngines.packageManager` field in the `package.json`](https://nodejs.org/api/corepack.html).
+**Optional** when `package.json` declares pnpm in `packageManager`, or sets `devEngines.packageManager.name` to `"pnpm"` and provides `devEngines.packageManager.version`.
 
 otherwise, this field is **required** It supports npm versioning scheme, it could be an exact version (such as `10.9.8`), or a version range (such as `10`, `10.x.x`, `10.9.x`, `^10.9.8`, `*`, etc.), or `latest`.
 
@@ -157,6 +157,8 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+      - uses: actions/checkout@v6
+
       - uses: pnpm/action-setup@v6
 ```