unittest mock: provide way to refer to method calls in a rename friendly manner

[DartBot]

<img src="https://avatars.githubusercontent.com/u/698895?v=3" align="left" width="96" height="96"hspace="10"> Issue by Andersmholmgren
Originally opened as dart-lang/sdk#15793

---

The unittest mock library uses strings to represent method calls. e.g.

foo.when(callsTo('fum')).thenReturn(...);

problem is when I want to rename fum then the IDE won't pick up my mocked method calls so I'll have to manually change them.

Issue dart-lang/sdk#13056 would provide a solution. Another option is a mockito style approach which I would imagine could be implemented today using noSuchMethod. e.g.

when(foo.fum()).thenReturn(...);

or

foo.when((f) => foo.fum()).thenReturn(...); // i.e. when calls the function with a second impl of Foo that captures the behaviour. Assuming you can dynamically implement an interface

http://stackoverflow.com/questions/20768280/refactor-friendly-mocking-in-dart

[DartBot]

<img src="https://avatars.githubusercontent.com/u/3276024?v=3" align="left" width="48" height="48"hspace="10"> Comment by anders-sandholm

---

Added Area-UnitTest, Triaged labels.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/698895?v=3" align="left" width="48" height="48"hspace="10"> Comment by Andersmholmgren

---

Added support for symbol literals for methods in dart-archive/bleeding_edge-DEPRECATED-USE-SDK-INSTEAD#8

[DartBot]

<img src="https://avatars.githubusercontent.com/u/17034?v=3" align="left" width="48" height="48"hspace="10"> Comment by kevmoo

---

Removed Area-UnitTest label.
Added Area-Pkg, Pkg-Unittest labels.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/17034?v=3" align="left" width="48" height="48"hspace="10"> Comment by kevmoo

---

Removed Pkg-Unittest label.
Added Pkg-mock label.