Add Prerelease input for latest prerelease resolution

MariusStorhaug · MariusStorhaug · commit eb32a654d6c3 · 2026-02-17T11:08:42.000+01:00
- Add 'Prerelease' boolean input (default: false), similar to
  Install-PSResource's -Prerelease switch
- When Prerelease is true and Version is 'latest', resolve to the latest
  prerelease from the PowerShell/PowerShell GitHub releases API
- Explicit prerelease version strings (e.g. 7.6.0-preview.6) continue to
  work directly without the Prerelease flag
- Add prerelease resolution to all 3 platform steps (Linux bash, macOS
  bash, Windows PowerShell 5.1)
- Update test workflow with 'prerelease' matrix entry
- Update README with Prerelease input docs and latest prerelease example
diff --git a/.github/workflows/Action-Test.yml b/.github/workflows/Action-Test.yml
@@ -22,7 +22,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]
-        version: ['latest', '7.4.7', '7.5.0', '7.6.0-preview.6']
+        version: ['latest', 'prerelease', '7.4.7', '7.5.0', '7.6.0-preview.6']
     runs-on: ${{ matrix.os }}
     name: '${{ matrix.os }} - [${{ matrix.version }}]'
     steps:
@@ -34,7 +34,8 @@ jobs:
       - name: Action-Test
         uses: ./
         with:
-          Version: ${{ matrix.version }}
+          Version: ${{ matrix.version == 'prerelease' && 'latest' || matrix.version }}
+          Prerelease: ${{ matrix.version == 'prerelease' && 'true' || 'false' }}
 
       - name: Verify installed version
         shell: pwsh
@@ -44,8 +45,19 @@ jobs:
           # Requested version that came from the matrix
           $requested = '${{ matrix.version }}'
 
+          # When 'prerelease' → resolve to latest prerelease
+          if ($requested.Trim().ToLower() -eq 'prerelease') {
+              $releases = Invoke-RestMethod -Uri 'https://api.github.com/repos/PowerShell/PowerShell/releases' `
+                -Headers @{
+                  'Accept' = 'application/vnd.github+json'
+                  'Authorization' = "Bearer $($env:GITHUB_TOKEN)"
+                  'X-GitHub-Api-Version' = '2022-11-28'
+                }
+              $requested = ($releases | Where-Object { $_.prerelease -eq $true } | Select-Object -First 1).tag_name.TrimStart('v')
+              Write-Host "Resolved 'prerelease' → $requested"
+          }
           # When empty / 'null' / 'latest' → resolve to latest stable release
-          if ([string]::IsNullOrWhiteSpace($requested) -or
+          elseif ([string]::IsNullOrWhiteSpace($requested) -or
               $requested.Trim().ToLower() -in @('latest','null')) {
 
               $requested = (
diff --git a/README.md b/README.md
@@ -35,11 +35,21 @@ jobs:
           Version: 7.6.0-preview.6
 ```
 
+### Installing the latest prerelease
+
+```yaml
+      - name: Install latest PowerShell Preview
+        uses: PSModule/install-powershell@v1
+        with:
+          Prerelease: true
+```
+
 ## Inputs
 
 | Input | Required | Default | Description |
 | ----- | -------- | ------- | ----------- |
-| `Version` | `false` | `latest` | Desired PowerShell Core version (e.g. `7.4.1`, `7.6.0-preview.6`). Use `latest` to install the newest stable release. Prerelease versions are supported. |
+| `Version` | `false` | `latest` | Desired PowerShell Core version (e.g. `7.4.1`, `7.6.0-preview.6`). Use `latest` to install the newest stable release (or newest prerelease when `Prerelease` is `true`). |
+| `Prerelease` | `false` | `false` | Install a prerelease version. When `true` and `Version` is `latest`, resolves to the latest prerelease. Similar to `-Prerelease` on `Install-PSResource`. |
 
 ## Secrets
 
@@ -53,8 +63,8 @@ This action does **not** generate any outputs.
 
 * **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. Prerelease version strings (e.g. `7.6.0-preview.6`) are passed
-  through directly.
+  `PowerShell/PowerShell` repository and substitutes that version. When `Prerelease` is `true`, it queries for the latest prerelease
+  instead. Explicit prerelease version strings (e.g. `7.6.0-preview.6`) are passed through directly.
 
 * **Skip logic**
   Before installing, the action checks the current runner to see whether the requested version is already available
diff --git a/action.yml b/action.yml
@@ -16,6 +16,13 @@ inputs:
       Prerelease versions are supported (e.g. `7.6.0-preview.6`, `7.5.0-rc.1`).
     required: false
     default: 'latest'
+  Prerelease:
+    description: |
+      Install a prerelease version of PowerShell.
+      When `true` and `Version` is `latest`, installs the latest prerelease.
+      Similar to the `-Prerelease` switch on `Install-PSResource`.
+    required: false
+    default: 'false'
 
 runs:
   using: composite
@@ -26,24 +33,38 @@ runs:
       working-directory: ${{ github.action_path }}
       env:
         REQUESTED_VERSION: ${{ inputs.Version }}
+        PRERELEASE: ${{ inputs.Prerelease }}
         GITHUB_TOKEN: ${{ github.token }}
       run: |
         # Install-PowerShell
         set -e
         echo "Requested version: [$REQUESTED_VERSION]"
+        echo "Prerelease: [$PRERELEASE]"
 
         # 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: $REQUESTED_VERSION"
+                if [[ "$PRERELEASE" == "true" ]]; 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 |
+                        jq -r '[.[] | select(.prerelease == true)] | .[0].tag_name' | sed 's/^v//'
+                    )
+                    echo "Latest prerelease PowerShell version detected: $REQUESTED_VERSION"
+                else
+                    REQUESTED_VERSION=$(
+                      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
                 ;;
             "")
                 echo "Error: Version input is required (or use 'latest')"
@@ -100,24 +121,38 @@ runs:
       working-directory: ${{ github.action_path }}
       env:
         REQUESTED_VERSION: ${{ inputs.Version }}
+        PRERELEASE: ${{ inputs.Prerelease }}
         GITHUB_TOKEN: ${{ github.token }}
       run: |
         # Install-PowerShell
         set -e
         echo "Requested version: [$REQUESTED_VERSION]"
+        echo "Prerelease: [$PRERELEASE]"
 
         # 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: $REQUESTED_VERSION"
+                if [[ "$PRERELEASE" == "true" ]]; 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 |
+                        jq -r '[.[] | select(.prerelease == true)] | .[0].tag_name' | sed 's/^v//'
+                    )
+                    echo "Latest prerelease PowerShell version detected: $REQUESTED_VERSION"
+                else
+                    REQUESTED_VERSION=$(
+                      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
                 ;;
             "")
                 echo "Error: Version input is required (or use 'latest')"
@@ -161,23 +196,29 @@ runs:
       working-directory: ${{ github.action_path }}
       env:
         REQUESTED_VERSION: ${{ inputs.Version }}
+        PRERELEASE: ${{ inputs.Prerelease }}
         GITHUB_TOKEN: ${{ github.token }}
       run: |
         # Install-PowerShell
         Write-Host "Requested version: [$env:REQUESTED_VERSION]"
+        Write-Host "Prerelease: [$env:PRERELEASE]"
 
         # Resolve 'latest' → concrete version
         $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)"
+            $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: $latest"
+            }
+            if ($env:PRERELEASE -eq 'true') {
+                $releases = Invoke-RestMethod -Uri 'https://api.github.com/repos/PowerShell/PowerShell/releases' -Headers $headers
+                $latest = ($releases | Where-Object { $_.prerelease -eq $true } | Select-Object -First 1).tag_name.TrimStart('v')
+                Write-Host "Latest prerelease PowerShell version detected: $latest"
+            } else {
+                $latest = (Invoke-RestMethod -Uri 'https://api.github.com/repos/PowerShell/PowerShell/releases/latest' -Headers $headers).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')"
