Flutter：单元测试

Question

I'm trying to test this function:

  setToday(Map filters) {
    if (filters['today'] == false) {
      filters['yesterday'] = false;
      filters['lastWeek'] = false;
      filters['lastMonth'] = false;
      filters['customRange'] = false;
      filters['today'] =  true;
    } else
      filters['today'] = false;
  }

And this is the test:

     test("", (){
        Map<String, bool> filters = {
          "today" : false,
          "yesterday" : false,
          "lastWeek" : false,
          "lastMonth" : false,
          "customRange" : false,
        };

        expect(_kpiFilterViewController.setToday(filters), filters["today"] == true);
      });

But the result is :

Expected: <true>
  Actual: <null>

What is my mistake?

Answer 1

Function under test does not return anything, so calling

_kpiFilterViewController.setToday(filters)

in the expect assertion will fail.

test("filters[today] value should be true", () {
    //Arrange
    Map<String, bool> filters = {
      "today" : false,
      "yesterday" : false,
      "lastWeek" : false,
      "lastMonth" : false,
      "customRange" : false,
    };
    bool expected = true;

    //Act (call the method under test)
    _kpiFilterViewController.setToday(filters);

    //Assert (verify expected behavior)
    bool actual = filters["today"];
    expect(actual, expected);
});

Reference Flutter: Introduction to unit testing