public void GetAllAsync_Called_CallsBuildUriWithFieldId() { // Given var client = new Mock <IRestClient>(); client.Setup(b => b.BuildUri(It.IsAny <string>(), It.IsAny <string>())).Returns(new Uri("http://search")); var organizationMembershipResource = new OrganizationMembershipResource(client.Object); // When organizationMembershipResource.GetAllAsync(4321); // Then client.Verify(c => c.BuildUri(It.Is <string>(st => st.Contains("4321")), "")); }