Don’t throw on assignments to non-assignable expressions. Allow non-literal indices in assignable e…

pkg/polymer_expressions/test/eval_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library eval_test;
 
 import 'dart:async';
 
 // Import mirrors to cause all mirrors to be retained by dart2js.
 // The tests reflect on LinkedHashMap.length and String.length.
@@ skipping 226 matching lines @@
       var child = new Foo(name: 'child');
       var parent = new Foo(child: child);
       assign(parse('child.name'), 'Joe', new Scope(model: parent));
       expect(parent.child.name, 'Joe');
     });
 
     test('should assign an index', () {
       var foo = new Foo(items: [1, 2, 3]);
       assign(parse('items[0]'), 4, new Scope(model: foo));
       expect(foo.items[0], 4);
+      assign(parse('items[a]'), 5, new Scope(model: foo, variables: {'a': 0}));
+      expect(foo.items[0], 5);
+    });
+
+    test('should assign with a function call subexpression', () {
+      var child = new Foo();
+      var foo = new Foo(items: [1, 2, 3], child: child);
+      assign(parse('getChild().name'), 'child', new Scope(model: foo));
+      expect(child.name, 'child');
     });
 
     test('should assign through transformers', () {
       var foo = new Foo(name: '42', age: 32);
       var globals = {
         'a': '42',
         'parseInt': parseInt,
         'add': add,
       };
       var scope = new Scope(model: foo, variables: globals);
       assign(parse('age | add(7)'), 29, scope);
       expect(foo.age, 22);
       assign(parse('name | parseInt() | add(10)'), 29, scope);
       expect(foo.name, '19');
     });
 
-    test('should throw on assignments to properties on null', () {
+    test('should not throw on assignments to properties on null', () {
       assign(parse('name'), 'b', new Scope(model: null));
     });
 
+    test('should throw on assignments to non-assignable expressions', () {
+      var foo = new Foo(name: 'a');
+      var scope = new Scope(model: foo);
+      expect(() => assign(parse('name + 1'), 1, scope),
+          throwsA(new isInstanceOf<EvalException>()));
+      expect(() => assign(parse('toString()'), 1, scope),
+          throwsA(new isInstanceOf<EvalException>()));
+      expect(() => assign(parse('name | filter'), 1, scope),
+          throwsA(new isInstanceOf<EvalException>()));
+    });
+
+    test('should not throw on assignments to non-assignable expressions if '
+        'checkAssignability is false', () {
+      var foo = new Foo(name: 'a');
+      var scope = new Scope(model: foo);
+      expect(
+          assign(parse('name + 1'), 1, scope, checkAssignability: false),
+          null);
+      expect(
+          assign(parse('toString()'), 1, scope, checkAssignability: false),
+          null);
+      expect(
+          assign(parse('name | filter'), 1, scope, checkAssignability: false),
+          null);
+    });
+
   });
 
   group('scope', () {
     test('should return fields on the model', () {
       var foo = new Foo(name: 'a', age: 1);
       var scope = new Scope(model: foo);
       expect(scope['name'], 'a');
       expect(scope['age'], 1);
     });
 
@@ skipping 66 matching lines @@
     _name = notifyPropertyChange(#name, _name, n);
   }
 
   int age;
   Foo child;
   List<int> items;
 
   Foo({name, this.age, this.child, this.items}) : _name = name;
 
   int x() => age * age;
+
+  getChild() => child;
+
+  filter(i) => i;
 }
 
 @reflectable
 class ListHolder {
   List items;
   ListHolder(this.items);
 }
 
 parseInt([int radix = 10]) => new IntToString(radix: radix);
 
@@ skipping 44 matching lines @@
   return Future.wait([future, new Future(() {
     expect(passed, true, reason: "Didn't receive a change notification on $s");
   })]);
 }
 
 // Regression test from https://code.google.com/p/dart/issues/detail?id=13459
 class WordElement extends Observable {
   @observable List chars1 = 'abcdefg'.split('');
   @reflectable List filteredList(List original) => [original[0], original[1]];
 }