Check in codegen test expectations.

test/codegen/expect/language/string_interpolate_null_test.js

Index: test/codegen/expect/language/string_interpolate_null_test.js
diff --git a/test/codegen/expect/language/string_interpolate_null_test.js b/test/codegen/expect/language/string_interpolate_null_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..5b1e26590aa542ff18b44b23199ca2c35c89b17d
--- /dev/null
+++ b/test/codegen/expect/language/string_interpolate_null_test.js
@@ -0,0 +1,39 @@
+dart_library.library('language/string_interpolate_null_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__string_interpolate_null_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 string_interpolate_null_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  string_interpolate_null_test.A = class A extends core.Object {
+    new(name) {
+      this.name = name;
+    }
+  };
+  dart.setSignature(string_interpolate_null_test.A, {
+    constructors: () => ({new: dart.definiteFunctionType(string_interpolate_null_test.A, [core.String])})
+  });
+  string_interpolate_null_test.main = function() {
+    let a = new string_interpolate_null_test.A("Kermit");
+    let s = dart.str`Hello Mr. ${a.name}`;
+    expect$.Expect.stringEquals("Hello Mr. Kermit", s);
+    a = null;
+    try {
+      s = dart.str`Hello Mr. ${a.name}`;
+    } catch (e) {
+      if (core.NoSuchMethodError.is(e)) {
+        return;
+      } else
+        throw e;
+    }
+
+    expect$.Expect.fail("NoSuchMethodError not thrown");
+  };
+  dart.fn(string_interpolate_null_test.main, VoidTodynamic());
+  // Exports:
+  exports.string_interpolate_null_test = string_interpolate_null_test;
+});