Separate gathering Delta changes and validation.

pkg/analyzer/test/src/context/context_test.dart

Index: pkg/analyzer/test/src/context/context_test.dart
diff --git a/pkg/analyzer/test/src/context/context_test.dart b/pkg/analyzer/test/src/context/context_test.dart
index c0a9b318cab0574a00ad4e75d9463d7307543eb3..06c5922e0207e3fc22ad02fe2f71ae0a2c1ba91e 100644
--- a/pkg/analyzer/test/src/context/context_test.dart
+++ b/pkg/analyzer/test/src/context/context_test.dart
@@ -3470,6 +3470,46 @@ class A {
     expect(context.getErrors(b).errors, hasLength(1));
   }
 
+  void test_sequence_dependenciesWithCycles() {
+    Source a = addSource(
+        '/a.dart',
+        r'''
+const A = 1;
+''');
+    Source b = addSource(
+        '/b.dart',
+        r'''
+import 'c.dart';
+const B = C1 + 1;
+''');
+    Source c = addSource(
+        '/c.dart',
+        r'''
+import 'a.dart';
+import 'b.dart';
+const C1 = A + 1;
+const C2 = B + 2;
+''');
+    Source d = addSource(
+        '/d.dart',
+        r'''
+import 'c.dart';
+const D = C2 + 1;
+''');
+    _performPendingAnalysisTasks();
+    // Update "A" constant.
+    // This should invalidate results in all sources.
+    context.setContents(
+        a,
+        r'''
+const A = 2;
+''');
+    _assertInvalid(a, LIBRARY_ERRORS_READY);
+    _assertInvalid(b, LIBRARY_ERRORS_READY);
+    _assertInvalid(c, LIBRARY_ERRORS_READY);
+    _assertInvalid(d, LIBRARY_ERRORS_READY);
+  }
+
   void test_sequence_inBodyChange_addRef_deltaChange() {
     Source a = addSource(
         '/a.dart',