Index: lib/runtime/dart/_foreign_helper.js |
diff --git a/lib/runtime/dart/_foreign_helper.js b/lib/runtime/dart/_foreign_helper.js |
index 166c7e190744f5463d6862e98106bf8312821187..81da65fbf7be58022304de11123a833d13261a2a 100644 |
--- a/lib/runtime/dart/_foreign_helper.js |
+++ b/lib/runtime/dart/_foreign_helper.js |
@@ -118,7 +118,7 @@ dart_library.library('dart/_foreign_helper', null, /* Imports */[ |
constructors: () => ({JS_CONST: [JS_CONST, [core.String]]}) |
}); |
function JS_STRING_CONCAT(a, b) { |
- return a + b; |
+ return dart.as(a + b, core.String); |
} |
dart.fn(JS_STRING_CONCAT, core.String, [core.String, core.String]); |
// Exports: |