Explicit type cast when asserting, inspecting, and diffing

[papandreou]

So that the base types can be utilized better.

Something like:

expect(expect.cast('object', new Error('blah')), 'to equal', {message: 'blah'});

function MyThing() {}
expect.addType({
    name: 'myThing',
    base: 'object',
    identify: function (obj) {
        return obj instanceof MyThing;
    },
    inspect: function (output, myThing, inspect, depth) {
        return output.text('MyThing: ').append(inspect(expect.cast('object', myThing)));
    },
    diff: function (output, actual, expected, diff) {
        var result = diff(expect.cast('object', actual), expect.cast('object', expected));
        result.diff.text("... and that's that");
        return result;
    }
});

Would be nice if it could accept a type name as well as a type object so that expect.cast(this.baseType, ...) could also work.

[papandreou]

Unfortunately this is not going to work like described above. Getting the cast type to "stick" when an assertion delegates to another assertion won't work without some sort of opt-in from each assertion, and that's a no-go. The use case is still there, but I'll work around it for now. Back to the drawing board.

[papandreou]

Landed the start of a spike on the cast branch.

[papandreou]

Needs special casing in it, equal, inspect, and diff on wrappedExpect when casts are active.