Prevent Pester from running when only non PS1 files are changed

.build/CodeFormatter.ps1

@@ -21,6 +21,7 @@ Set-StrictMode -Version Latest
 . $PSScriptRoot\CodeFormatterChecks\CheckScriptFileHasComplianceHeader.ps1
 . $PSScriptRoot\CodeFormatterChecks\CheckKeywordCasing.ps1
 . $PSScriptRoot\CodeFormatterChecks\CheckScriptFormat.ps1
+. $PSScriptRoot\HelpFunctions\Get-CommitFilesOnBranch.ps1
 
 if (-not (Load-Module -Name PSScriptAnalyzer -MinimumVersion "1.20")) {
     throw "PSScriptAnalyzer module could not be loaded"
@@ -33,46 +34,10 @@ if (-not (Load-Module -Name EncodingAnalyzer)) {
 $repoRoot = Get-Item "$PSScriptRoot\.."
 
 $optimizeCodeFormatter = [string]::IsNullOrEmpty($Branch) -eq $false
-$filesFullPath = New-Object 'System.Collections.Generic.HashSet[string]'
 # Get only the files that are changed in this PR
 if ($optimizeCodeFormatter) {
 
-    Write-Verbose "Checking commits only"
-    # Get all the commits between origin/$Branch and HEAD.
-    $gitlog = git log --format="%H %cd" --date=rfc origin/$Branch..HEAD
-    $m = $gitlog | Select-String "^(\S+) (.*)$"
-
-    foreach ($commitMatch in $m) {
-        $commitHash = $commitMatch.Matches.Groups[1].Value
-        $filesChangedInCommit = git diff-tree --no-commit-id --name-only -r $commitHash
-
-        foreach ($fileChanged in $filesChangedInCommit) {
-            $fullPath = Join-Path $repoRoot $fileChanged
-
-            if (-not (Test-Path $fullPath)) {
-                # not typical scenario, but want to have the pipeline continue
-                Write-Verbose "File no longer exists, skip file: $fullPath"
-                continue
-            }
-
-            Write-Verbose "Adding commit file to list: $fullPath"
-            [void]$filesFullPath.Add($fullPath)
-        }
-    }
-
-    # Also include modified files, but not committed yet for local work.
-    $gitStatus = git status --short
-    $m = $gitStatus | Select-String "M (.*)"
-    foreach ($match in $m) {
-        $file = $match.Matches.Groups[1].Value.Trim()
-        $fullPath = Join-Path $PSScriptRoot $file
-
-        Write-Verbose "Adding modified file to list: $fullPath"
-        [void]$filesFullPath.Add($fullPath)
-    }
-
-    Write-Verbose "Files changed or modified"
-    $filesFullPath | Write-Verbose
+    $filesFullPath = Get-CommitFilesOnBranch -Branch $Branch
 
     # Only optimize CodeFormatter IF any CodeFormatter related files were not modified or PSScriptAnalyzerSettings.psd1
     $optimizeCodeFormatter = $null -eq ($filesFullPath | Where-Object { $_ -like "*.build\CodeFormatter*" -or $_ -like "*\PSScriptAnalyzerSettings.psd1" })

.build/HelpFunctions/Get-CommitFilesOnBranch.ps1

@@ -0,0 +1,53 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# This should only be called if we have a branch that we want to compare against
+function Get-CommitFilesOnBranch {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]
+        $Branch
+    )
+    $filesFullPath = New-Object 'System.Collections.Generic.HashSet[string]'
+    $repoRoot = Get-Item "$PSScriptRoot\..\.."
+
+    Write-Verbose "Checking commits only"
+    # Get all the commits between origin/$Branch and HEAD.
+    $gitlog = git log --format="%H %cd" --date=rfc origin/$Branch..HEAD
+    $m = $gitlog | Select-String "^(\S+) (.*)$"
+
+    foreach ($commitMatch in $m) {
+        $commitHash = $commitMatch.Matches.Groups[1].Value
+        $filesChangedInCommit = git diff-tree --no-commit-id --name-only -r $commitHash
+
+        foreach ($fileChanged in $filesChangedInCommit) {
+            $fullPath = Join-Path $repoRoot $fileChanged
+
+            if (-not (Test-Path $fullPath)) {
+                # not typical scenario, but want to have the pipeline continue
+                Write-Verbose "File no longer exists, skip file: $fullPath"
+                continue
+            }
+
+            Write-Verbose "Adding commit file to list: $fullPath"
+            [void]$filesFullPath.Add($fullPath)
+        }
+    }
+
+    # Also include modified files, but not committed yet for local work.
+    $gitStatus = git status --short
+    $m = $gitStatus | Select-String "M (.*)"
+    foreach ($match in $m) {
+        $file = $match.Matches.Groups[1].Value.Trim()
+        $fullPath = Join-Path $PSScriptRoot $file
+
+        Write-Verbose "Adding modified file to list: $fullPath"
+        [void]$filesFullPath.Add($fullPath)
+    }
+
+    Write-Verbose "Files changed or modified"
+    $filesFullPath | Write-Verbose
+
+    return $filesFullPath
+}

.build/Pester.ps1

@@ -3,11 +3,16 @@
 
 [CmdletBinding()]
 param(
-    [switch]$NoProgress
+    [switch]
+    $NoProgress,
+
+    [string]
+    $Branch
 )
 
 begin {
     . $PSScriptRoot\Load-Module.ps1
+    . $PSScriptRoot\HelpFunctions\Get-CommitFilesOnBranch.ps1
 
     if (-not (Load-Module -Name Pester -MinimumVersion 5.2.0)) {
         throw "Pester module could not be loaded"
@@ -25,6 +30,16 @@ begin {
     $stopWatch = [System.Diagnostics.Stopwatch]::StartNew()
 } process {
 
+    if (-not ([string]::IsNullOrEmpty($Branch))) {
+        Write-Host "Checking commits on Branch $Branch"
+        $committedFiles = Get-CommitFilesOnBranch -Branch $Branch
+        # if the branch only has doc changes return
+        if ($null -eq ($committedFiles | Where-Object { $_.EndsWith(".ps1") } )) {
+            Write-Host "No Commits on PS1 files, skipping over pester testing."
+            return
+        }
+    }
+
     $root = Get-Item "$PSScriptRoot\.."
     $scripts = @(Get-ChildItem -Recurse $root |
             Where-Object { $_.Name -like "*.Tests.ps1" })
@@ -118,7 +133,8 @@ begin {
 
     Write-Host
 
-    if (-not $NoProgress) {
+    if (-not $NoProgress -and
+        $null -ne $parentProgress) {
         Write-Progress @parentProgress -Completed
     }
     $sumTotalSeconds = 0

azure-pipeline-merge.yml

@@ -25,8 +25,10 @@ steps:
 
 - pwsh: |
     cd .\.build
-    .\Pester.ps1 -NoProgress
+    .\Pester.ps1 -NoProgress -Branch $env:TargetBranchName
   displayName: "Running Invoke-Pester"
+  env:
+    TargetBranchName: $(System.PullRequest.TargetBranch)
 
 - pwsh: |
     cd .\.build