Can Gomega's Equal() handle multiple values ?

Question

I am testing a function to send a mock request to a server using gomega and I want to verify that 1. the request has started 2. the request has completed. For this I am returning two booleans. They should both evaluate to true in the example below but the values will be subject to change. I have tried this:

g := gomega.NewGomegaWithT(t)
...
g.Eventually(func() (bool, bool) {
...
    start = false
    end = true

    if (request.status == "started") {
        start = true
    }
    if (request.status == "complete") {
        end = true
    }
    return start, end
}).Should(Equal((true, true))

But it seems that gomega's Equal() does not handle multiple variables. Is there any way around this? Is it bad practice to evaluate two return values ?

Answer 1

You can use a wrapper function I wrote based on your pseudocode

g := gomega.NewGomegaWithT(t)
...
testedFunc := func() (bool, bool) {
...
    start = false
    end = true

    if (request.status == "started") {
        start = true
    }
    if (request.status == "complete") {
        end = true
    }
    return start, end
}

g.Eventually(func() map[string]bool{
    r1,r2 := testedFunc()
    return map[string]bool{"start": r1, "end": r2}
}).Should(Equal(map[string]bool{"start": true, "end": true}))

I'm using a map instead of simple r1&r2for verbosity, so, you can see what is actually wrong with the results. In my opinion, it's a bad practice to compare 2 return values unless the second one is an error. You can always combine multiple return values in a single language construct (map, slice, struct, etc.) as I did in my wrapper function. I understand it's hard to do with the async Eventually method, but in general, I'd try to assert each of the return values separately.

Answer 2

In gomega's doc, It has been said that multiple return is ok to be used.

The function that you pass to Eventually can have more than one return value. In that case, Eventually passes the first return value to the matcher and asserts that all other return values are nil or zero-valued. This allows you to use Eventually with functions that return a value and an error – a common pattern in Go

In your code, can you change this line

.Should(Equal((true, true)) to .Should(Equal(true, true).

That should fix the problem.

Edit:

I overlooked that Equal only receives one interface parameter. My bad.

For future reference, for comparing multiple values in gomega's eventually,Array of struct (or any datatype) can be useful.