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

[srabraham]

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

Assuming you read that issue first, and especially https://github.com/smartystreets/goconvey/issues/665#issuecomment-1489390117 , 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).