Enhance performance of DSC resource integration tests by adding early source change check and update README with detailed flow diagram

Author: johlju

.build/README.md

@@ -18,7 +18,8 @@ resources and classes, then checks if any relevant files have been modified.
 
 The script performs an optimized analysis by checking for changes in this order:
 
-1. **Early Source Check**: First checks if any files under `source/` have changed
+1. **Early Source Check**: First checks if any files under the configured
+   source path (`-SourcePath`, default `source/`) have changed
    - If no source changes, skips integration tests immediately
 1. **DSC Resources**: Files under `source/DSCResources/`
 1. **Classes**: Files under `source/Classes/`
@@ -42,7 +43,7 @@ flowchart TD
     GetChanges --> HasChanges{Any Changed<br/>Files?}
     HasChanges -->|No| RunTrue[Return TRUE<br/>Run integration tests]
 
-    HasChanges -->|Yes| CheckSource{Any Changes<br/>Under source/?}
+    HasChanges -->|Yes| CheckSource{Any Changes<br/>Under SourcePath?}
     CheckSource -->|No| Skip[Return FALSE<br/>Skip integration tests]
 
     CheckSource -->|Yes| Discover[Discover Public Commands<br/>Used by DSC Resources]

.build/Test-ShouldRunDscResourceIntegrationTests.ps1

@@ -460,7 +460,8 @@ function Test-ShouldRunDscResourceIntegrationTests
     Write-Host ""
 
     # Early optimization: Check if any changes are under the source folder
-    $changedSourceFiles = $changedFiles | Where-Object -FilterScript { $_ -match '^source/' }
+    $sourcePrefix = '^' + [regex]::Escape((($SourcePath -replace '\\','/') -replace '/+$','')) + '/'
+    $changedSourceFiles = $changedFiles | Where-Object -FilterScript { $_ -match $sourcePrefix }
     if (-not $changedSourceFiles)
     {
         Write-Host "No changes detected under the source folder. DSC resource integration tests can be skipped."

CHANGELOG.md

@@ -80,8 +80,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     all changes.
 - Bump actions/checkout task to v5.
 - `.build/Test-ShouldRunDscResourceIntegrationTests.ps1`
-  - Improved performance by adding early optimization to check for changes
-    under source folder before expensive analysis.
+  - Improved performance by adding an early optimization to check for changes
+    under the source folder before expensive analysis.
   - Moved public command discovery to only run when source changes are detected.
 - `.build/README.md`
   - Added flow diagram showing decision process for DSC resource integration tests.