Fix duplicate checkout in extensions

Author: shivammathur

extension/BuildPhpExtension/BuildPhpExtension.psd1

@@ -81,6 +81,7 @@
         'Add-Vs',
         'Get-ArgumentsFromConfig',
         'Get-BuildDirectory',
+        'Get-CheckoutState',
         'Get-Extension',
         'Get-ExtensionConfig',
         'Get-ExtensionName',

extension/BuildPhpExtension/private/Get-CheckoutState.ps1

@@ -0,0 +1,37 @@
+Function Get-CheckoutState {
+    <#
+    .SYNOPSIS
+        Get whether the current directory already contains the expected repository checkout.
+    .PARAMETER Repository
+        Expected owner/repository name.
+    #>
+    [OutputType([string])]
+    param(
+        [Parameter(Mandatory = $false, Position=0, HelpMessage='Expected owner/repository name.')]
+        [string] $Repository = ''
+    )
+    begin {
+    }
+    process {
+        if([string]::IsNullOrWhiteSpace($Repository)) {
+            $Repository = $env:GITHUB_REPOSITORY
+        }
+
+        if([string]::IsNullOrWhiteSpace($Repository) -or -not(Test-Path .git)) {
+            return $false.ToString().ToLowerInvariant()
+        }
+
+        try {
+            $originUrl = git remote get-url origin 2>$null
+            if($LASTEXITCODE -ne 0 -or [string]::IsNullOrWhiteSpace($originUrl)) {
+                return $false.ToString().ToLowerInvariant()
+            }
+
+            return ($originUrl -match "(^|[:/])$([regex]::Escape($Repository))(\.git)?$").ToString().ToLowerInvariant()
+        } catch {
+            return $false.ToString().ToLowerInvariant()
+        }
+    }
+    end {
+    }
+}

extension/action.yml

@@ -58,7 +58,15 @@ inputs:
 runs:
   using: composite
   steps:
+    - name: Check checkout state
+      id: checkout-state
+      shell: pwsh
+      run: |
+        Import-Module ${{ github.action_path }}\BuildPhpExtension -Force
+        Add-Content -Path $env:GITHUB_OUTPUT -Value "checkout_state=$(Get-CheckoutState -Repository $env:GITHUB_REPOSITORY)" -Encoding utf8
+
     - name: Checkout
+      if: ${{ steps.checkout-state.outputs.checkout_state == 'false' }}
       uses: actions/checkout@v5
 
     - name: Check VS components