PSModule · MariusStorhaug · Apr 21, 2025 · Apr 20, 2025 · Apr 20, 2025 · Apr 20, 2025
diff --git a/.github/linters/.jscpd.json b/.github/linters/.jscpd.json
@@ -4,7 +4,8 @@
         "consoleFull"
     ],
     "ignore": [
-        "**/tests/**"
+        "**/tests/**",
+        "**/action.yml"
     ],
     "absolute": true
 }
diff --git a/.github/workflows/Action-Test.yml b/.github/workflows/Action-Test.yml
@@ -18,15 +18,50 @@ permissions:
 
 jobs:
   ActionTestBasic:
-    name: Action-Test - [Basic]
-    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+        version: ['latest', '7.4.7', '7.5.0']
+    runs-on: ${{ matrix.os }}
+    name: '${{ matrix.os }} - [${{ matrix.version }}]'
     steps:
-      # Need to check out as part of the test, as its a local action
       - name: Checkout repo
         uses: actions/checkout@v4
 
       - name: Action-Test
         uses: ./
         with:
-          working-directory: ./tests
-          subject: PSModule
+          Version: ${{ matrix.version }}
+
+      - name: Verify installed version
+        shell: pwsh
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          # Requested version that came from the matrix
+          $requested = '${{ matrix.version }}'
+
+          # When empty / 'null' / 'latest' → resolve to latest stable release
+          if ([string]::IsNullOrWhiteSpace($requested) -or
+              $requested.Trim().ToLower() -in @('latest','null')) {
+
+              $requested = (
+                Invoke-RestMethod -Uri 'https://api.github.com/repos/PowerShell/PowerShell/releases/latest' `
+                -Headers @{
+                  'Accept' = 'application/vnd.github+json'
+                  'Authorization' = "Bearer $($env:GITHUB_TOKEN)"
+                  'X-GitHub-Api-Version' = '2022-11-28'
+                }
+              ).tag_name.TrimStart('v')
+              Write-Host "Resolved 'latest' → $requested"
+          }
+
+          # Actual version installed by the action
+          $installed = ($PSVersionTable.PSVersion).ToString()
+          Write-Host "Installed PowerShell version: $installed"
+          Write-Host "Expected  PowerShell version: $requested"
+
+          if ($installed -ne $requested) {
+              throw "Failed: expected $requested but got $installed"
+          }
diff --git a/README.md b/README.md
@@ -1,17 +1,61 @@
-# Template-Action
+# Install-PowerShell
 
-A template repository for GitHub Actions
+A cross‑platform GitHub Action that installs a specific **PowerShell Core** version—or the latest stable release—on any GitHub‑hosted runner
+(Linux, macOS, or Windows). The action automatically skips installation when the requested version is already present.
 
 ## Usage
 
-### Inputs
+Add the action to a job in your workflow file:
 
-### Secrets
-
-### Outputs
+```yaml
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
 
-### Example
+      - name: Install PowerShell
+        uses: PSModule/install-powershell@v1
+        with:
+          Version: 7.5.0
 
-```yaml
-Example here
+      - name: Run a PowerShell script
+        shell: pwsh
+        run: |
+          Write-Host "Using PowerShell $($PSVersionTable.PSVersion)"
 ```
+
+## Inputs
+
+| Input   | Required | Default | Description |
+| ------- | -------- | ------- | ----------- |
+| `Version` | `false` | `latest` | Desired PowerShell Core version (e.g. `7.4.1`). Use `latest` to install the newest stable release. |
+
+## Secrets
+
+This action does **not** require any secrets.
+
+## Outputs
+
+This action does **not** generate any outputs.
+
+## How it works
+
+* **Version resolution**
+  If `Version` is set to `latest` (case‑insensitive), the action queries the GitHub API for the newest stable release tag in the
+  `PowerShell/PowerShell` repository and substitutes that version.
+
+* **Skip logic**
+  Before installing, the action checks the current runner to see whether the requested version is already available
+  (`pwsh -Command $($PSVersionTable.PSVersion)`). If it matches, the step ends immediately.
+
+* **Platform‑specific installers**
+
+  | Runner OS | Install strategy |
+  | --------- | ---------------- |
+  | **Linux** (Debian/Ubuntu‑based) | Uses APT if available; otherwise downloads the `.deb` asset directly from the release page and installs with `dpkg`. |
+  | **macOS** | Prefers Homebrew Cask (`brew install --cask powershell`) and falls back to downloading the `.pkg` installer. ARCH detection (`arm64` / `x64`) is automatic. |
+  | **Windows** | Downloads the corresponding `.msi` package and installs silently with `msiexec`. |
+
+* **Error handling**
+  The step fails with a clear error message if the requested version cannot be resolved or if the operating‑system distribution is unsupported (e.g., non‑APT Linux distros).
diff --git a/action.yml b/action.yml
@@ -1,48 +1,203 @@
-name: {{ NAME }}
-description: {{ DESCRIPTION }}
+name: Install PowerShell
+description: |
+  Install a specific version —or the latest stable version— of PowerShell Core
+  on any GitHub runner (Linux, macOS, Windows).
+  Skips the install if the requested version is already present.
 author: PSModule
 branding:
-  icon: upload-cloud
-  color: white
+  icon: terminal
+  color: purple
 
 inputs:
-  subject:
-    description: The subject to greet
-    required: false
-    default: World
-  Debug:
-    description: Enable debug output.
-    required: false
-    default: 'false'
-  Verbose:
-    description: Enable verbose output.
-    required: false
-    default: 'false'
   Version:
-    description: Specifies the version of the GitHub module to be installed. The value must be an exact version.
-    required: false
-  Prerelease:
-    description: Allow prerelease versions if available.
+    description: |
+      PowerShell version to install (e.g. `7.4.1`).
+      Defaults to install the latest stable release.
     required: false
-    default: 'false'
-  WorkingDirectory:
-    description: The working directory where the script will run from.
-    required: false
-    default: ${{ github.workspace }}
+    default: 'latest'
 
 runs:
   using: composite
   steps:
-    - name: {{ NAME }}
-      uses: PSModule/GitHub-Script@v1
+    - name: Install PowerShell (Linux)
+      if: runner.os == 'Linux'
+      shell: bash
+      env:
+        REQUESTED_VERSION: ${{ inputs.Version }}
+        GITHUB_TOKEN: ${{ github.token }}
+      run: |
+        set -e
+
+        echo "Requested version: [$REQUESTED_VERSION]"
+
+        # Only resolve to latest version if explicitly set to 'latest' (case-insensitive)
+        case "${REQUESTED_VERSION:-}" in
+            [Ll][Aa][Tt][Ee][Ss][Tt])
+                REQUESTED_VERSION=$(
+                  curl -s -f \
+                    -H "Accept: application/vnd.github+json" \
+                    -H "Authorization: Bearer $GITHUB_TOKEN" \
+                    -H "X-GitHub-Api-Version: 2022-11-28" \
+                    https://api.github.com/repos/PowerShell/PowerShell/releases/latest |
+                    jq -r '.tag_name' | sed 's/^v//'
+                )
+                echo "Latest stable PowerShell release detected: $REQUESTED_VERSION"
+                ;;
+            "")
+                echo "Error: Version input is required (or use 'latest')"
+                exit 1
+                ;;
+        esac
+
+        DETECTED_VERSION=$(pwsh -NoLogo -NoProfile -Command '$PSVersionTable.PSVersion.ToString()' 2>/dev/null || true)
+        if [[ "$DETECTED_VERSION" == "$REQUESTED_VERSION" ]]; then
+          echo "PowerShell $DETECTED_VERSION already installed. Skipping."
+          exit 0
+        fi
+
+        if command -v apt-get >/dev/null; then
+          echo "Using APT package manager (Debian/Ubuntu)..."
+
+          if ! grep -q "packages.microsoft.com" /etc/apt/sources.list /etc/apt/sources.list.d/* 2>/dev/null; then
+            wget -qO- https://packages.microsoft.com/keys/microsoft.asc \
+              | sudo tee /etc/apt/trusted.gpg.d/microsoft.asc > /dev/null
+            DIST_CODENAME=$(lsb_release -cs)
+            sudo add-apt-repository \
+              "deb [arch=$(dpkg --print-architecture)] https://packages.microsoft.com/ubuntu/$DIST_CODENAME/prod $DIST_CODENAME main"
+          fi
+
+          sudo apt-get update -y
+          EXACT_PKG=$(apt-cache madison powershell | awk '{print $3}' \
+            | grep -E "^${REQUESTED_VERSION}(-|$)" | head -n1 || true)
+
+          if [[ -n "$EXACT_PKG" ]]; then
+            sudo apt-get install -y powershell=$EXACT_PKG
+          else
+            ARCH=$(dpkg --print-architecture)
+            DEB_NAME="powershell_${REQUESTED_VERSION}-1.deb_${ARCH}.deb"
+            URL="https://github.com/PowerShell/PowerShell/releases/download/v${REQUESTED_VERSION}/${DEB_NAME}"
+            wget -q "$URL" -O "$DEB_NAME"
+            sudo dpkg -i "$DEB_NAME" || sudo apt-get -f install -y
+          fi
+        else
+          echo "Unsupported Linux distribution (no apt-get)."
+          exit 1
+        fi
+
+    - name: Install PowerShell (macOS)
+      if: runner.os == 'macOS'
+      shell: bash
       env:
-        {{ ORG }}_{{ NAME }}_INPUT_subject: ${{ inputs.subject }}
-      with:
-        Debug: ${{ inputs.Debug }}
-        Prerelease: ${{ inputs.Prerelease }}
-        Verbose: ${{ inputs.Verbose }}
-        Version: ${{ inputs.Version }}
-        WorkingDirectory: ${{ inputs.WorkingDirectory }}
-        Script: |
-          # {{ NAME }}
-          ${{ github.action_path }}/scripts/main.ps1
+        REQUESTED_VERSION: ${{ inputs.Version }}
+        GITHUB_TOKEN: ${{ github.token }}
+      run: |
+        set -e
+
+        echo "Requested version: [$REQUESTED_VERSION]"
+
+        # Convert to lowercase for comparison (macOS-compatible method)
+        REQ_VER_LOWER=$(echo "$REQUESTED_VERSION" | tr '[:upper:]' '[:lower:]')
+
+        # Only resolve to latest version if explicitly set to 'latest'
+        if [[ "$REQ_VER_LOWER" == "latest" ]]; then
+          REQUESTED_VERSION=$(
+            curl -s -f \
+              -H "Accept: application/vnd.github+json" \
+              -H "Authorization: Bearer $GITHUB_TOKEN" \
+              -H "X-GitHub-Api-Version: 2022-11-28" \
+              https://api.github.com/repos/PowerShell/PowerShell/releases/latest |
+              jq -r '.tag_name' | sed 's/^v//'
+          )
+          echo "Latest stable PowerShell release detected: $REQUESTED_VERSION"
+        fi
+
+        # Validate REQUESTED_VERSION is not empty
+        if [[ -z "${REQUESTED_VERSION}" ]]; then
+          echo "Error: Could not determine a valid PowerShell version."
+          exit 1
+        fi
+
+        DETECTED_VERSION=$(pwsh -NoLogo -NoProfile -Command '$PSVersionTable.PSVersion.ToString()' 2>/dev/null || true)
+        if [[ "$DETECTED_VERSION" == "$REQUESTED_VERSION" ]]; then
+          echo "PowerShell $DETECTED_VERSION already installed. Skipping."
+          exit 0
+        fi
+
+        # Try Homebrew first (simplified approach)
+        if command -v brew >/dev/null; then
+          echo "Using Homebrew package manager..."
+          # Homebrew handles 'latest' automatically when no version is specified
+          if [[ "$REQ_VER_LOWER" == "latest" ]]; then
+            brew install --cask powershell
+          else
+            # Try specific version formula first
+            if brew install --cask "powershell@$REQUESTED_VERSION" 2>/dev/null; then
+              echo "Successfully installed via Homebrew"
+            else
+              # Fall back to generic formula if versioned one doesn't exist
+              echo "Version-specific formula not found, installing latest via Homebrew"
+              brew install --cask powershell
+            fi
+          fi
+        else
+          # Fall back to direct download
+          echo "Homebrew not available, downloading directly..."
+          ARCH=$(uname -m)
+          case "$ARCH" in
+            "arm64") PKG_NAME="powershell-${REQUESTED_VERSION}-osx-arm64.pkg" ;;
+            *)       PKG_NAME="powershell-${REQUESTED_VERSION}-osx-x64.pkg" ;;
+          esac
+
+          URL="https://github.com/PowerShell/PowerShell/releases/download/v${REQUESTED_VERSION}/${PKG_NAME}"
+          echo "Downloading from: $URL"
+          if ! curl -sSL "$URL" -o "$PKG_NAME"; then
+            echo "Error: Failed to download PowerShell package"
+            exit 1
+          fi
+          sudo installer -pkg "$PKG_NAME" -target /
+        fi
+
+    - name: Install PowerShell (Windows)
+      if: runner.os == 'Windows'
+      shell: powershell
+      env:
+        REQUESTED_VERSION: ${{ inputs.Version }}
+        GITHUB_TOKEN: ${{ github.token }}
+      run: |
+        Write-Host  "Requested version: [$REQUESTED_VERSION]"
+        # Only resolve to latest version if explicitly set to 'latest' (case-insensitive)
+        $req = $env:REQUESTED_VERSION
+        if ($req -and $req.Trim().ToLower() -eq 'latest') {
+            $latest = (
+              Invoke-RestMethod -Uri 'https://api.github.com/repos/PowerShell/PowerShell/releases/latest' `
+              -Headers @{
+                'Accept' = 'application/vnd.github+json'
+                'Authorization' = "Bearer $($env:GITHUB_TOKEN)"
+                'X-GitHub-Api-Version' = '2022-11-28'
+              }
+            ).tag_name.TrimStart('v')
+            Write-Host "Latest stable PowerShell release detected: $latest"
+            $env:REQUESTED_VERSION = $latest
+        } elseif ([string]::IsNullOrWhiteSpace($req)) {
+            Write-Host "Error: Version input is required (or use 'latest')"
+            exit 1
+        }
+
+        try {
+          $detected = (pwsh -NoLogo -NoProfile -Command '$PSVersionTable.PSVersion.ToString()')
+        } catch {
+          $detected = $null
+        }
+
+        Write-Host "Detected PowerShell version: $detected"
+        Write-Host "Requested PowerShell version: $env:REQUESTED_VERSION"
+
+        if ($detected -eq $env:REQUESTED_VERSION) {
+          Write-Host "PowerShell $detected already installed. Skipping."
+          exit 0
+        }
+
+        $msi = "PowerShell-$($env:REQUESTED_VERSION)-win-x64.msi"
+        $url = "https://github.com/PowerShell/PowerShell/releases/download/v$($env:REQUESTED_VERSION)/$msi"
+        Invoke-WebRequest -Uri $url -OutFile $msi -UseBasicParsing
+        Start-Process msiexec.exe -ArgumentList '/i', $msi, '/quiet', '/norestart' -Wait