chore(CI): directory specific test change pruning (terraform-google-modules#669)

* chore(CI): directory specific test change pruning

---------

Co-authored-by: Katie McLaughlin <katie@glasnt.com>

Author: apeabody

.github/.keep

@@ -28,27 +28,33 @@ steps:
       fi
 
       git fetch --unshallow
-      git diff origin/${_BASE_BRANCH} --name-only > _changed_files
-      sed 's/\/.*/\//' _changed_files > _changed_folders
+      git diff origin/main --name-only > _changed_files
+      sed 's:[^/]*$::' _changed_files > _changed_folders
+      sort -u -o _changed_folders{,}
+      echo Folders with changes:
+      cat _changed_folders
 
       # Do not prune if changing tests themselves
-      _INFRA_FOLDERS="build test .github"
-      for d in _changed_folders; do
-        if [[ "${_INFRA_FOLDERS}" =~ "$d" ]]; then
-          echo "Infrastructure folders have changed; no tests will be pruned."
+      while read d; do
+        if [[ "build test .github" =~ "${d%/}" ]]; then
+          echo "Infrastructure folder ${d%/} has changed; no tests will be pruned."
           exit 0 # do not prune
         fi
-      done
+      done < _changed_folders
 
-      for d in */; do
-          if ! grep -q "^$d" _changed_folders && [[ "$d" != "test/" ]]; then
-            rm -rf $d;
+      # Remove leaf folders without changes or non-tf resources
+      for d in `find . -type d -name 'test' -prune -o -links 2 -printf '%P\n'`; do
+          if ! grep -q "^$d" _changed_folders && ! [ -n "$(find $d -maxdepth 1 -not -name '*.tf' -type f -print -quit)" ]; then
+            rm -rf $d
           fi
       done
 
+      # Remove any empty folders
+      find . -empty -type d -delete
+
       # Report remaining folders
       echo Folders in scope for tests:
-      for d in */; do echo $d; done
+      find . -type d -printf '%P\n'
 
 - id: prepare
   name: 'gcr.io/cloud-foundation-cicd/$_DOCKER_IMAGE_DEVELOPER_TOOLS:$_DOCKER_TAG_VERSION_DEVELOPER_TOOLS'

build/int.cloudbuild.yaml

@@ -18,7 +18,7 @@
 # [START gke_standard_regional_labels_cluster]
 resource "google_container_cluster" "default" {
   name               = "gke-standard-regional-labels"
-  location           = "us-west1"
+  location           = "us-central1"
   initial_node_count = 2
 
   resource_labels = {