There are legitimate cases to use td.verify #389
Description
Description
When you want a software to maintain consistent behaviour, you may want to use unit test to ensure code change won't break. There are some cases to use td.verify.
Issue
The warning
'test double was both stubbed and verified with arguments, which is redundant and probably unnecessary' is not necessary in some cases. Can this warning be turned off?
Examples
- Use unit test to ensure future code change will not cause regression bug
In the following example, having stubbed does not ensure runProcess will always perform all the 3 steps.
We have to put td.verify in to ensure these 3 steps should be performed all times.
let td = require('testdouble');
let mock: any;
it('process_should_contains_3_steps', () => {
td.when(mock.performStepA(td.machers.anything()))
.thenResolve({ status: 'ok' })
td.when(mock.performStepB(td.machers.anything()))
.thenResolve({ status: 'ok' })
td.when(mock.performStepC(td.machers.anything()))
.thenResolve({ status: 'ok' })
myClass.runProcess()
.then((result) => {
td.verify(mock.performStepA(td.machers.anything()), { times: 1 });
td.verify(mock.performStepB(td.machers.anything()), { times: 1 });
td.verify(mock.performStepC(td.machers.anything()), { times: 1 });
})
});
- Use unit tests to ensure it process correctly based on data
In this example, setup of stub is outside of individual unit test. The behaviour of unit tests will be different based on test data. We use td.verify to ensure code change won't break.
let td = require('testdouble');
let mock: any;
td.when(mock.perform(td.machers.anything()))
.thenResolve({ status: 'ok' })
it('process_should_perform_on_data_1', () => {
myClass.runProcess()
.then((result) => {
td.verify(mock.perform(td.machers.anything()), { times: 1 });
})
});
it('process_should_not_perform_on_data_2', () => {
myClass.runProcess()
.then((result) => {
td.verify(mock.perform(td.machers.anything()), { times: 0 });
})
});