ShouldResemble can fail when there's no visual diff between the inputs

[srabraham]

This was initially filed as an issue on goconvey: smartystreets/goconvey#665
But really it's a problem in this assertions code.

Assuming you read that issue first, and especially smartystreets/goconvey#665 (comment) , the right fix would be for the diff to report which types are different. That would be a little involved, especially if anyone has managed to rely on the exact output format that is provided currently.
A lazier fix would be something like the below

func ShouldResemble(actual interface{}, expected ...interface{}) string {
	if message := need(1, expected); message != success {
		return message
	}

	if matchError := oglematchers.DeepEquals(expected[0]).Matches(actual); matchError != nil {
		renderedExpected, renderedActual := render.Render(expected[0]), render.Render(actual)
		message := fmt.Sprintf(shouldHaveResembled, renderedExpected, renderedActual)

		if renderedExpected != renderedActual {
			message += composePrettyDiff(renderedExpected, renderedActual)
		} else {
			message += "No visual diff, but there is a difference in type within expected versus actual"
		}
		return serializer.serializeDetailed(expected[0], actual, message)
	}

	return success
}

FYI @riannucci

[mdwhatcott]

I'd welcome a PR with code similar to what @srabraham suggested above (including test cases please).