Check in codegen test expectations.

test/codegen/expect/language/exception_test.js

+dart_library.library('language/exception_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__exception_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const exception_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  exception_test.ExceptionTest = class ExceptionTest extends core.Object {
+    static testMain() {
+      let i = 0;
+      try {
+        dart.throw("Hello");
+      } catch (s) {
+        if (core.String.is(s)) {
+          core.print(s);
+          i = i + 10;
+        } else
+          throw s;
+      }
+
+      try {
+        dart.throw("bye");
+      } catch (s) {
+        if (core.String.is(s)) {
+          core.print(s);
+          i = i + 10;
+        } else
+          throw s;
+      }
+
+      expect$.Expect.equals(20, i);
+      let correctCatch = false;
+      try {
+        dart.throw(null);
+      } catch (e$) {
+        if (core.String.is(e$)) {
+          let s = e$;
+          correctCatch = false;
+        } else if (core.NullThrownError.is(e$)) {
+          let e = e$;
+          correctCatch = true;
+        } else {
+          let x = e$;
+          correctCatch = false;
+        }
+      }
+
+      expect$.Expect.isTrue(correctCatch);
+    }
+  };
+  dart.setSignature(exception_test.ExceptionTest, {
+    statics: () => ({testMain: dart.definiteFunctionType(dart.dynamic, [])}),
+    names: ['testMain']
+  });
+  exception_test.main = function() {
+    exception_test.ExceptionTest.testMain();
+  };
+  dart.fn(exception_test.main, VoidTodynamic());
+  // Exports:
+  exports.exception_test = exception_test;
+});