# Mirage vs FactoryGuyfor data mocking

**URL:** <https://discuss.emberjs.com/t/mirage-vs-factoryguyfor-data-mocking/8736>\
**Category:** Testing\
**Created:** [September 3, 2015, 9:05pm UTC](https://discuss.emberjs.com/t/mirage-vs-factoryguyfor-data-mocking/8736 "2015-09-03T21:05:34Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Andrew\_Max](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/andrew_max/32/11193_2.png) [@Andrew\_Max](https://discuss.emberjs.com/u/Andrew_Max)\
**Post date:** [September 3, 2015, 9:05pm UTC](https://discuss.emberjs.com/t/mirage-vs-factoryguyfor-data-mocking/8736/1 "2015-09-03T21:05:34Z")

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I am in the process of setting up ember tests for the first time and one big question is how to deal with data mocking.

I was wondering if anyone had any insight as to pros and cons for Mirage and Factory Guy

I know mirage is based on mocking an entire server which seems good in the sense that it matches reality a little bit more closely but it also seems like extra work both in writing the mocks and instantiating them.

I was wondering if anyone had any perspective on that trade off or any other anecdotal experience about which they had liked more and why.

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**Author:** ![xcambar](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/xcambar/32/11309_2.png) [@xcambar](https://discuss.emberjs.com/u/xcambar)\
**Post date:** [September 3, 2015, 10:27pm UTC](https://discuss.emberjs.com/t/mirage-vs-factoryguyfor-data-mocking/8736/2 "2015-09-03T22:27:08Z")

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In my opinion, the difference of features is blurring between the two, but the API and history makes it all. Here’s a list of comparison points that I can think of:

- Mirage always focused on mocking the server, which makes it agnostic to Ember adapters. **Mirage goes with or without Ember Data**.
- FactoryGuy focuses on Ember Data. **If you don’t use EmberData, move away from FactoryGuy**.

&nbsp;

- FactoryGuy _seems_ to have a nicer/more complete API for handling HTTP errors in tests. Or at the very least, closer to the standard API we’re used in testing our Ember apps.
- But I didn’t notice any difference in the feature set on mocking HTTP behaviour.

&nbsp;

- Mirage started with Fixtures and added functionnality up to factories along the way.
- FactoryGuy started with factories in mind, they’re more powerful, with traits and globally better specifications of “what I want to test now”. “Simple” fixtures are possible but it’s ridiculous tu use FG with static fixtures (which is both a pro and a con).

&nbsp;

- FactoryGuy allows for a greater variability of your tests, but comes at a cost.
- Mirage is simpler, but edge cases will stay hidden from testing until you manually add them.

&nbsp;

**tl;dr;** Mirage is easier and faster, but FactoryGuy more powerful and heavyweight.

**my personal preference:**

I personnally went with Mirage and apart from the management of relationships (which is getting better and better), I never had to complain. FactoryGuy is a very muscular beast, but I’m afraid at some point you’re in need to test the factories you use for testing, if you see what I mean.

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<div class="post-metadata">

**Author:** ![Andrew\_Max](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/andrew_max/32/11193_2.png) [@Andrew\_Max](https://discuss.emberjs.com/u/Andrew_Max)\
**Post date:** [September 4, 2015, 4:02pm UTC](https://discuss.emberjs.com/t/mirage-vs-factoryguyfor-data-mocking/8736/3 "2015-09-04T16:02:32Z")

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Excellent and very in depth comparison! I think I was conceiving of what their strong points were incorrectly in some cases so this was very clarifying.

Thanks!