Check in codegen test expectations.

test/codegen/expect/language/cascade_2_test.js

+dart_library.library('language/cascade_2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__cascade_2_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const _interceptors = dart_sdk._interceptors;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const cascade_2_test = Object.create(null);
+  let JSArrayOfElement = () => (JSArrayOfElement = dart.constFn(_interceptors.JSArray$(cascade_2_test.Element)))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  cascade_2_test.main = function() {
+    let a = new cascade_2_test.Element(null);
+    expect$.Expect.equals(1, a.path0[dartx.length]);
+    expect$.Expect.equals(a, a.path0[dartx.get](0));
+    expect$.Expect.equals(2, a.path1[dartx.length]);
+    expect$.Expect.equals(a, a.path1[dartx.get](0));
+    expect$.Expect.equals(a, a.path1[dartx.get](1));
+    expect$.Expect.equals(1, a.path2[dartx.length]);
+    let b = new cascade_2_test.Element(a);
+    expect$.Expect.equals(2, b.path0[dartx.length]);
+    expect$.Expect.equals(a, b.path0[dartx.get](0));
+    expect$.Expect.equals(b, b.path0[dartx.get](1));
+    expect$.Expect.equals(3, b.path1[dartx.length]);
+    expect$.Expect.equals(a, b.path1[dartx.get](0));
+    expect$.Expect.equals(a, b.path1[dartx.get](1));
+    expect$.Expect.equals(b, b.path1[dartx.get](2));
+    expect$.Expect.equals(2, b.path2[dartx.length]);
+  };
+  dart.fn(cascade_2_test.main, VoidTodynamic());
+  cascade_2_test.Element = class Element extends core.Object {
+    new(parent) {
+      this.parent = parent;
+    }
+    get path0() {
+      if (this.parent == null) {
+        return JSArrayOfElement().of([this]);
+      } else {
+        let _ = this.parent.path0;
+        _[dartx.add](this);
+        return _;
+      }
+    }
+    get path1() {
+      let _ = this.parent == null ? JSArrayOfElement().of([this]) : this.parent.path1;
+      _[dartx.add](this);
+      return _;
+    }
+    get path2() {
+      return this.parent == null ? JSArrayOfElement().of([this]) : (() => {
+        let _ = this.parent.path2;
+        _[dartx.add](this);
+        return _;
+      })();
+    }
+  };
+  dart.setSignature(cascade_2_test.Element, {
+    constructors: () => ({new: dart.definiteFunctionType(cascade_2_test.Element, [cascade_2_test.Element])})
+  });
+  // Exports:
+  exports.cascade_2_test = cascade_2_test;
+});