Better error output for toHaveBeenCalledWith #60
Description
First, great project! I'm sure you saw my tweet of praise:
toHaveBeenCalledWith
Anyway, having replaced sinon with this, I've noticed that this very readable call...
expect(this.say).toHaveBeenCalledWith("foo");...yields an error with only half of the picture. There's no telling what it was called with, or never called at all:
Error: spy was never called with [ 'foo' ]
toEqual
However, explicitly using toEqual is much more useful:
expect(this.say.calls[0].arguments).toEqual(["foo"]);[
- "bar"
+ "foo"
]Proposal
I'd recommend mimicking the output of toEqual.
When the spy was called & matched.
No changes.
(Patch) When the spy was never called.
"say" was never called
(Patch) Show all calls.
"name" was called N times without ["foo"]:
1 with ["bar"]
2 with [undefined]
...
(Breaking Feature) Expect the assertion to always reference the last call (e.g. spy.calls[spy.calls.length -1].
This is a suggestion for a possible future release that's largely unrelated to this issue.
"name" was last called with ["bar"], expected ["foo"].
What I like about this approach is that it works great for repeated assertions:
const query = function(params) {
return axios.get("/api", { params });
};
var spy = expect.spyOn(axios, "get");
query({ foo: "foo" });
expect(spy).toHaveBeenCalledWith("/api", { foo: "foo" });
query({ bar: "bar" });
expect(spy).toHaveBeenCalledWith("/api", { bar: "bar" });I only list it here because improving the usability of toHaveBeenCalledWith will lend itself to more use :)
What do you think @mjackson?