ioutil.ReadAll error testing.

[Dr Yann Golanski]

I am trying to test the following line of code:

func ook() error {
        […]
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return errors.Wrap(err, "cannot read body, trying again")
	}

This is my test:

func (errReader) Read(p []byte) (int, error) {
	return 1, errors.New("Computer says NON!")
}

// Wait for vault to unseal: body error.
func TestWaitForVaultToUnsealBodyError(t *testing.T) {
	defer gock.Off() // Flush pending mocks after test execution

	gock.New(URL).
		Get("v1/seal-status").
		Reply(200).
		Body(errReader{})

        ook()
}

I removed the URL and other extra stuff, the code is a little (but not much) more complex than that. However, the ioutil.ReadAll refuses to spew an error. What am I doing wrong?

[Rafael Piovesan C Machado]

I've managed to test this using something as follows:

serverAPI := httptest.NewServer(
	http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
                // says the response is longer than what we're actually returning
		w.Header().Add("Content-Length", "50")
                // return less bytes, wich will result in an "unexpected EOF" from ioutil.ReadAll()
		_, _ = w.Write([]byte("a"))
	}),
)
defer serverAPI.Close()

[Ivan Bertona]

Same issue here. The problem is that this library immediately consumes that response buffer and will have the mock RoundTripper return (nil, error) instead of (*http.Response, nil) (with the reader as *http.Response.Body).