feat: cah.processWorkflow returns the hash (#4751)

Author: jtmcdole

app_dart/lib/src/service/content_aware_hash_service.dart

@@ -129,12 +129,14 @@ interface class ContentAwareHashService {
   }
 
   /// Finds the hash status for [job] and updates any tracking docs.
-  Future<MergeQueueHashStatus> processWorkflowJob(
+  Future<ContentAwareHashStatus> processWorkflowJob(
     WorkflowJobEvent job, {
     @visibleForTesting RetryOptions retry = const RetryOptions(maxAttempts: 5),
   }) async {
     final hash = await hashFromWorkflowJobEvent(job);
-    if (hash == null) return MergeQueueHashStatus.ignoreJob;
+    if (hash == null) {
+      return (status: MergeQueueHashStatus.ignoreJob, contentHash: '');
+    }
 
     final headSha = job.workflowJob!.headSha!;
 
@@ -155,14 +157,14 @@ interface class ContentAwareHashService {
           rethrow;
         }
       });
-      return result;
+      return (status: result, contentHash: hash);
     } catch (e, s) {
       log.warn(
         'CAHS(headSha: $headSha, hash: $hash): multiple failures calling _updateFirestore',
         e,
         s,
       );
-      return MergeQueueHashStatus.error;
+      return (status: MergeQueueHashStatus.error, contentHash: '');
     }
   }
 
@@ -337,3 +339,6 @@ interface class ContentAwareHashService {
 }
 
 enum MergeQueueHashStatus { wait, build, complete, ignoreJob, error }
+
+typedef ContentAwareHashStatus =
+    ({String contentHash, MergeQueueHashStatus status});

app_dart/lib/src/service/scheduler.dart

@@ -676,11 +676,12 @@ $s
       //   - .*: do nothing
       // FOR NOW: trigger builds for build/wait/completed because they are also
       //          building for SHA.
-      switch (artifactStatus) {
+      switch (artifactStatus.status) {
         case MergeQueueHashStatus.build ||
                 MergeQueueHashStatus.wait ||
                 MergeQueueHashStatus.complete
-            when _config.flags.contentAwareHashing.waitOnContentHash:
+            when _config.flags.contentAwareHashing.waitOnContentHash &&
+                artifactStatus.contentHash.isNotEmpty:
           // Note from codefu: We do not have the merge queue lock yet.
           // It was short-circuited if the waitOnContentHash is set. The
           // CAH document _has_ been created. In the future, "wait" will need

app_dart/test/service/content_aware_hash_service_test.dart

@@ -156,7 +156,10 @@ void main() {
 
       final job = workflowJobTemplate(headSha: 'a' * 40).toWorkflowJob();
       final result = await cahs.processWorkflowJob(job);
-      expect(result, MergeQueueHashStatus.build);
+      expect(result, (
+        status: MergeQueueHashStatus.build,
+        contentHash: '1111111111111111111111111111111111111111',
+      ));
       expect(
         firestoreService,
         existsInStorage(ContentAwareHashBuilds.metadata, [
@@ -186,7 +189,10 @@ void main() {
 
       final job = workflowJobTemplate(headSha: 'b' * 40).toWorkflowJob();
       final result = await cahs.processWorkflowJob(job);
-      expect(result, MergeQueueHashStatus.complete);
+      expect(result, (
+        contentHash: '1111111111111111111111111111111111111111',
+        status: MergeQueueHashStatus.complete,
+      ));
     });
 
     test('stacks multiple builds in one doc', () async {
@@ -199,7 +205,10 @@ void main() {
 
       job = workflowJobTemplate(headSha: 'b' * 40).toWorkflowJob();
       final result = await cahs.processWorkflowJob(job);
-      expect(result, MergeQueueHashStatus.wait);
+      expect(result, (
+        contentHash: '1111111111111111111111111111111111111111',
+        status: MergeQueueHashStatus.wait,
+      ));
 
       expect(
         firestoreService,
@@ -224,7 +233,10 @@ void main() {
 
       job = workflowJobTemplate(headSha: 'b' * 40).toWorkflowJob();
       final result = await cahs.processWorkflowJob(job);
-      expect(result, MergeQueueHashStatus.wait);
+      expect(result, (
+        contentHash: '1111111111111111111111111111111111111111',
+        status: MergeQueueHashStatus.wait,
+      ));
 
       expect(
         firestoreService,
@@ -255,7 +267,7 @@ void main() {
         job,
         retry: const RetryOptions(maxAttempts: 5, maxDelay: Duration.zero),
       );
-      expect(result, MergeQueueHashStatus.error);
+      expect(result, (contentHash: '', status: MergeQueueHashStatus.error));
     });
   });
 

app_dart/test/src/service/fake_content_aware_hash_service.dart

@@ -44,15 +44,17 @@ class FakeContentAwareHashService implements ContentAwareHashService {
   }
 
   final processWorkflowJobs = <WorkflowJobEvent>[];
-  MergeQueueHashStatus? nextStatusReturn;
+  ContentAwareHashStatus? nextStatusReturn;
 
   @override
-  Future<MergeQueueHashStatus> processWorkflowJob(
+  Future<ContentAwareHashStatus> processWorkflowJob(
     WorkflowJobEvent workflow, {
     RetryOptions? retry,
   }) {
     processWorkflowJobs.add(workflow);
-    final status = nextStatusReturn ?? MergeQueueHashStatus.ignoreJob;
+    final status =
+        nextStatusReturn ??
+        (status: MergeQueueHashStatus.ignoreJob, contentHash: '');
     nextStatusReturn = null;
     return Future.value(status);
   }