feat: verify HasNotBeenCalled (#10)

verify.go

@@ -21,3 +21,8 @@ func (verifier *CallVerifier) HasBeenCalled(expectedCallsCount int) []*Invocatio
 func (verifier *CallVerifier) HasBeenCalledOnce() *Invocation {
 	return verifier.HasBeenCalled(1)[0]
 }
+
+// HasNotBeenCalled asserts that no HTTP call has been made.
+func (verifier *CallVerifier) HasNotBeenCalled() {
+	_ = verifier.HasBeenCalled(0)
+}

verify_test.go

@@ -155,3 +155,41 @@ func TestVerifyingSingleInvocationReturnsThePerformedCall(t *testing.T) {
 		WithStringPayload("Hello").
 		WithHeader("Content-Type", "text/plain")
 }
+
+func TestVerifyingNoInvocationPasses(t *testing.T) {
+	t.Parallel()
+	// Arrange
+	testState := NewTestingMock(t)
+	mockedAPI := API(testState)
+	defer func() { mockedAPI.Close() }()
+
+	mockedAPI.
+		Stub(http.MethodGet, "/endpoint").
+		WithStatusCode(http.StatusOK)
+
+	// Act
+	mockedAPI.Verify(http.MethodGet, "/endpoint").HasNotBeenCalled()
+
+	// Assert
+	testState.assertDidNotFailed()
+}
+
+func TestVerifyingNoInvocationFails(t *testing.T) {
+	t.Parallel()
+	// Arrange
+	testState := NewTestingMock(t)
+	mockedAPI := API(testState)
+	defer func() { mockedAPI.Close() }()
+
+	mockedAPI.
+		Stub(http.MethodGet, "/endpoint").
+		WithStatusCode(http.StatusOK)
+
+	// Act
+	client := http.Client{}
+	_, _ = client.Get(mockedAPI.GetURL().String() + "/endpoint")
+	mockedAPI.Verify(http.MethodGet, "/endpoint").HasNotBeenCalled()
+
+	// Assert
+	testState.assertFailedWithFatal()
+}