Test reflecting on an object that implements Function but has no call method.

tests/lib/mirrors/fake_function_without_call_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.
+
+import "dart:mirrors";
+
+import "package:expect/expect.dart";
+
+class MultiArityFunction implements Function {
+  noSuchMethod(Invocation msg) {
+    if (msg.memberName != #call) return super.noSuchMethod(msg);
+    return msg.positionalArguments.join(",");
+  }
+}
+
+main() {
+  var f = new MultiArityFunction();
+
+  Expect.isTrue(f is Function);
+  Expect.equals('a', f('a'));
+  Expect.equals('a,b', f('a', 'b'));
+  Expect.equals('a,b,c', f('a', 'b', 'c'));
+  Expect.equals('a', Function.apply(f, ['a']));
+  Expect.equals('a,b', Function.apply(f, ['a', 'b']));
+  Expect.equals('a,b,c', Function.apply(f, ['a', 'b', 'c']));
+  Expect.throws(() => f.foo('a', 'b', 'c'),
+                (e) => e is NoSuchMethodError);
+
+  InstanceMirror im = reflect(f);
+  Expect.isFalse(im is ClosureMirror);

[ahe, 2013/10/10 14:33:51]

I thought we had agreed that something that implements Function is a closure
mirror.

[rmacnak, 2013/10/10 16:24:00]

Something that implements call. In this case, what would ClosureMirror.function
return?

[ahe, 2013/10/10 16:48:55]

I see the following options:

1. return null.
2. throw an exception.
3. what getField(#call) would do.

+}