Update Maven cache cleaning script for edge case (Azure#45146)

Update Maven cache cleaning script for edge case

Author: alzimmermsft

eng/scripts/Remove-Azure-Artifacts-From-Cache.ps1

@@ -38,6 +38,7 @@ foreach ($rootFolder in $rootFolders) {
     # For each artifact root folder try to find maven-metadata-central.xml as that will determine which versions
     # of the artifact to retain in the DevOps cache.
     $mavenMetadataCentralPath = Join-Path -Path $artifactRootFolder -ChildPath "maven-metadata-central.xml"
+    $mavenCentralVersions = {}
     if (Test-Path -Path $mavenMetadataCentralPath) {
       # Folder contains a 'maven-metadata-central.xml' file, parse it to determine which subfolders should be deleted.
       #
@@ -46,18 +47,52 @@ foreach ($rootFolder in $rootFolders) {
       # folders which is constant with the previous design where the root folders were indiscriminately cleaned, best case
       # this only deletes built from source folders.
       $metadataXml = [XML](Get-Content $mavenMetadataCentralPath)
-      $versions = Select-Xml -Xml $metadataXml -XPath "/metadata/versioning/versions/version" | ForEach-Object {$_.Node.InnerXml}
-      foreach ($versionFolder in (Get-ChildItem -Path $artifactRootFolder -Directory)) {
-        if (!$versions.Contains($versionFolder.Name)) {
-          Write-Host "Deleting folder '$versionFolder' as the version isn't in 'maven-metadata-central.xml'."
-          Remove-Item $versionFolder -Recurse -ErrorAction Ignore
-        }
-      }
+      $mavenCentralVersions = Select-Xml -Xml $metadataXml -XPath "/metadata/versioning/versions/version" | ForEach-Object {$_.Node.InnerXml}
     } else {
       # Folder doesn't contain a 'maven-metadata-central.xml' file, delete the entire folder as it cannot be determined
       # what was built from source vs resolved from Maven central.
       Write-Host "Deleting folder '$artifactRootFolder' as it doesn't have a 'maven-metadata-central.xml' file."
       Remove-Item $artifactRootFolder -Recurse -ErrorAction Ignore
+      continue
+    }
+
+    $mavenMetadataLocalPath = Join-Path -Path $artifactRootFolder -ChildPath "maven-metadata-local.xml"
+    $mavenLocalVersions = {}
+    if (Test-Path -Path $mavenMetadataLocalPath) {
+      # Folder contains a 'maven-metadata-local.xml' file, parse it to determine which subfolders should be deleted.
+      #
+      # For example the metadata file lists azure-core 1.33.0 and 1.34.0-beta.1 and there are folders 1.33.0 and 1.34.0-beta.1
+      # all folders will be deleted as Maven built those versions locally. Worst case, this over deletes folders which is constant
+      # with the previous design where the root folders were indiscriminately cleaned, best case this only deletes built from source folders.
+      $metadataXml = [XML](Get-Content $mavenMetadataLocalPath)
+      $mavenLocalVersions = Select-Xml -Xml $metadataXml -XPath "/metadata/versioning/versions/version" | ForEach-Object {$_.Node.InnerXml}
+
+      # Additionally, since we know the file exists, delete it. We don't want to cache information about what packages were built
+      # locally as this could change build-to-build. For example, in one job 1.30.0 could be built locally while releasing, but
+      # in the next job 1.31.0-beta.1 could be built locally as the version incremented. We don't want the file to then state both
+      # 1.30.0 and 1.31.0-beta.1 were built locally.
+      Write-Host "Deleting maven-metadata-local.xml '$mavenMetadataLocalPath'."
+    }
+
+    # Now loop over each directory in this package. These directories should be the versions built locally or resolved from
+    # Maven central.   
+    foreach ($versionFolder in (Get-ChildItem -Path $artifactRootFolder -Directory)) {
+      # Both maven-metadata-central.xml and maven-metadata-local.xml are used with inverse checks as it's a possibility that
+      # the project was built locally while Maven central also contains the package. This could happen when a PR has the prep
+      # work for a release but doesn't pull in changes from main after the release completes. 
+      #
+      # Ex, 1.30.0 is being released, so the PR uses 1.30.0 as the package version, but if the PR doesn't pull from main after
+      # the version increments to 1.31.0-beta.1 the job will have 1.30.0 in both maven-metadata-central.xml and maven-metadata.local.xml.
+      # It's safer to over delete what will be in the cache than to have incorrect data. 
+      if (!$mavenCentralVersions.Contains($versionFolder.Name)) {
+        # If maven-metadata-central.xml doesn't contain the version this is an explicit indicator the package was built locally.
+        Write-Host "Deleting folder '$versionFolder' as the version isn't in 'maven-metadata-central.xml'."
+        Remove-Item $versionFolder -Recurse -ErrorAction Ignore
+      } elseif ($mavenLocalVersions.Contains($versionFolder.Name)) {
+        # If maven-metadata-local.xml contains the version this is an explicit indicator the package was built locally.
+        Write-Host "Deleting folder '$versionFolder' as the version is in 'maven-metadata-local.xml'."
+        Remove-Item $versionFolder -Recurse -ErrorAction Ignore
+      }
     }
   }
 }