Thanks @navijatio. I love this idea. I would make it even strict: to force only the checked value to be only a function call, that only returns one value of error type.

Do you want to implement this?

@nunnatsa yeah that makes sense, Expect(err).To(Not(Suceed()) doesn't feel very readable. I'll see if I or anyone I know can take this on this week.

Thinking about it again, this is a good linter rule, but I think the real fix will be to fix the Succeed matcher itself, to always check the last return value, if it's a nil error, ignoring the rest of the return values, and won't limit itself to a single return value.

For example, this is a very common patterns when using gomega:

_, err := funcReturnsValueAndError()
Expect(err).ToNot(HaveOccurred())
...
Expect(funcReturnsOnlyError()).To(Succeed())

I think it makes more sense that the this code will work:

Expect(funcReturnsValueAndError()).To(Succeed())
...
Expect(funcReturnsOnlyError()).To(Succeed())

@onsi - what do you think?