Dart Mocking a Function

问题:

How do I test that a mocked function was called?

I found this example on Mocking with Dart - How to test that a function passed as a parameter was called? and tried to extend it to check if the function was called.

library test2;

import "package:unittest/unittest.dart";
import "package:mock/mock.dart";

class MockFunction extends Mock {
  call(int a, int b) => a + b;
}

void main() {
  test("aa", () {

    var mockf = new MockFunction();
    expect(mockf(1, 2), 3);
    mockf.getLogs(callsTo(1, 2)).verify(happenedOnce);
  });
}

It appears that the mockf.getLogs() structure is empty...

回答1:

You must mock methods and specify their names in the log. Here's working code:

library test2;

import "package:unittest/unittest.dart";
import "package:mock/mock.dart";

class MockFunction extends Mock {
  MockFunction(){
    when(callsTo('call')).alwaysCall(this.foo);
  }
  foo(int a, int b) {
    return a + b;
    }
}

void main() {
  test("aa", () {    
    var mockf = new MockFunction();
    expect(mockf(1, 2), 3);
    mockf.calls('call', 1, 2).verify(happenedOnce);
  });
}

edit: answer to the similar question: Dart How to mock a procedure