Originally the expctations required that the return values be specified
immediately after the method name and arguments, otherwise the call
setup will either panic (best case) or silently modify the *previous*
call specification (worst case).
This change moves the Return(), Run(), Once(), etc methods onto the Call
struct, and changes the chaining behaviour so that they modify the Call
data directly rather than referencing the last item in the ExpectedCalls
array.
There is race condition caused when a method being tested calls a mocked
method within a go routine. For example, caching might be done a go
routine and that caching might be mocked.
There is already a mutex protecting the lists on the Mock object -
however Return() appends to ExpectedCalls and findExpectedCall could
run at the same time.
Comparting a float with NaN is always false so the assertion would always pass.
Added a check that either the actual or expected values are NaN.
InDelta will now fail if either the actual or expected value are NaN.
We cannot compare two Func arguments to check if they are equal using
the reflect package. This leads to the following misleading panic:
```go
handler := func(http.ResponseWriter, *http.Request) {}
muxMock.On("HandleFunc", "/", handler)
muxMock.HandleFunc("/", handler)
// panics arguing handler != handler
```
Since we cannot fix this behaviour using reflection, this patch
provides a better panic with a meaningful workaround.
```go
handler := func(http.ResponseWriter, *http.Request) {}
muxMock.On("HandleFunc", "/", handler)
// panics recommending defining the expectatin with:
// AnythingOfType("func(http.ResponseWriter, *http.Request)")
```
Solution following the panic's instructions:
```go
handler := func(http.ResponseWriter, *http.Request) {}
muxMock.On("HandleFunc", "/",
mock.AnythingOfType("func(http.ResponseWriter, *http.Request)"))
muxMock.HandleFunc("/", handler)
```
Some methods in Go take a pointer to a struct or a map and are supposed
to set some values in the referenced argument. Using Return is not
enough to mock such methods.
We are introducing a Run method that allows setting a Call handler to
make your mock update such referenced values.
Example usage mocking a service that finds a user in a data store and
fills the values in the provided struct:
```go
m.On("Find", 1, mock.AnythingOfType(*User))
.Return(nil)
.Run(func(args mock.Arguments) {
u := args.Get(0).(*User)
u.ID = 1
u.Email = "mail@example.com"
})
```