Unit Test Examples

[dvmorris]

Could you provide some unit test examples or a pattern for using a framework like chai? I am using the Meteor Chef's Base template, and I am trying to extend this file to include a test for when the insertDocument.call() function fails validation and throws an Error.

I have tried a ton of different things, but I can't seem to get it to work. Could you provide some sample code for that?

[ghost]

I am using this kind of pattern to test a method that throws an error

chai.assert.throws(() => {
   insertDocument._execute({ /* user id if required*/}, {/*method params*/});
   }, Meteor.Error, /you error message/
);

hope it can help you.

[stubailo]

There are a ton of examples here: https://github.com/meteor/todos/blob/master/imports/api/lists/lists.tests.js

Do those cover your case?

[dvmorris]

Thanks for the quick reply. Just to clarify, you are using ._execute instead of ._call to run the function. Does that make a difference?

Also, when I try out the example above (using .call instead of .execute), I am getting the following errors when running the tests with mocha:

• Server: Error: expected [Function] to throw 'Error' but 'Error: Start Date cannot be in the past' was thrown
• Client: AssertionError: expected [Function] to throw Error

Also, when I change the last parameter of assert.throws() to:

}, /Start Date cannot be in the past/

instead of:

}, Meteor.Error, /Error: Start Date cannot be in the past/);

The server test passes, but the client test still fails with the same error.

[stubailo]

I can't debug with that little information - can you paste more code? But the reason we use _execute is so that we can:

1. Avoid making a network request in a unit test
2. Pass in custom stuff for this, like userId, etc

[dvmorris]

I apologize. Here is a more detailed code sample. I am still new to Meteor and this kind of JavaScript programming in general, so I really appreciate your help and your patience:

// the test method
it('fails to insert a shift alert because start date is in the past', function () {
    var name = 'Invalid Shift - Happened in the Past';
    var date = moment().subtract(3, 'days');
    assert.throws(() => {
      insertShiftAlert.call({
        groupId: faker.random.uuid(),
        name: name,
        start: date.toDate(),
        end: date.add(12, 'hours').toDate(),
        slots_available: 1,
        sub_shifts_available: false
      })
    }, Meteor.Error, /Error: Start Date cannot be in the past/);
  });

// the method I am trying to test 
export const insertShiftAlert = new ValidatedMethod({
  name: 'shift-alerts.insert',
  validate: new SimpleSchema({
    groupId: { type: String },
    name: { type: String },
    start: { type: Date },
    end: { type: Date },
    slots_available: { type: Number },
    sub_shifts_available: { type: Boolean }
  }).validator(),
  run(shiftAlert) {
    ShiftAlerts.insert(shiftAlert);
  },
});

// the portion of the SimpleSchema definition that does validation on start date
...
start: {
    type: Date,
    label: 'The start date/time of the shift',
    custom: function () {
      if (moment(this.value).diff(moment()) < 0 ) {
        return "startDateInPast";
      }
    },
    srf: {
      type: 'text',
    },
  },
...

[lnmunhoz]

@stubailo Is it possible to create a test to check if a given method its using a mixin? In my case, I have a method that updates a document just if the user is the owner of the document, so I created I mixin to check this using the ziarno:restrict-mixin. Do you have any example about a possible implementation using chai?

Please check our test implementation here.