[nnbd_migration] Assert an edge origin exists in _checkAssignment

MichaelRFairhurst · commit-bot@chromium.org · commit dc366a5ad526 · 2020-02-28T23:26:22.000Z
Change-Id: If2b9d9c4cfdf35b67df478cc20ed16fe6b868b44 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137823 Reviewed-by: Paul Berry <paulberry@google.com> Commit-Queue: Mike Fairhurst <mfairhurst@google.com>
diff --git a/pkg/nnbd_migration/lib/src/edge_builder.dart b/pkg/nnbd_migration/lib/src/edge_builder.dart
@@ -2634,6 +2634,7 @@ mixin _AssignmentChecker {
       @required bool hard,
       bool checkable = true,
       bool sourceIsFunctionLiteral = false}) {
+    assert(origin != null);
     var sourceType = source.type;
     var destinationType = destination.type;
     if (!_typeSystem.isSubtypeOf(sourceType, destinationType)) {
