How to use Stub object with tinytest and meteorjs? - testing

Question

This weekend i tryed to test a package "A" from my meteor app.
This package depends on another package "B" that defines all collections. So the package "B" expose all required collections.
The package "A" expose a main object that have some methods that use the collections exposed in "B".
I want to replace some collections by a code like this :
myCol = {
"findOne": return {_id: 1, "name": ben}
}
But it fails. This code is ok from tinytest.add code, but in the methods of the package "A", it still uses the original Collection variables. I've seen in the build folder that everything is re-written by the build system, so i wonder what is the best way to test my code without depending on those Collection variables.
I have some ideas like storing those variables in a main object that has get/set methods. It might allow me to change everything when i do test.
Thanks for help
Here is the sample app : https://github.com/MeteorLyon/tutorial-package-dependancy-testing
Follow the README.md to run different test.
If you find a solution it's great.

Answer 1

If you are looking for stubs, I'd highly recommend using sinon. Specifically, have a look at the stubs and the sandbox portions of the docs. You can find atmosphere packages here. Here's a quick example:
Tinytest.add('my test', sinon.test(function(test) {
// this is sandboxed stub - we are writing to a global object
// but it will be restored at the end of the test
test.stub(Meteor, 'userId', function() {
return USER_ID;
});
// let's do the same thing with a collection
test.stub(Posts, 'findOne', function() {
return {_id: 1, name: 'ben'};
});
var post = Posts.findOne();
test.equal(post.name, 'ben');
}));
Keep in mind that tinytest is an integration test framework, so you may get better tests by fully utilizing both package's APIs. With respect to testing collection interactions, we've found its better to not stub very much and just insert and cleanup as needed. But that's pretty general advice - there may be some specific reason why this can't work in your particular use case.