When I've used ORMs in the past, the approach we took was to substitute an in memory driver. View more quick examples below, or dive into the API docs, which also provides useful pointers on how and when to use the various functionality. Postgres) supports but available in-memory databases (like SQLite) don't. (Thanks in All the expectation methods return the expectation, meaning you can chain them. @benoittgt Thank you! I'm using client pooling which (i think) further complicates the matter of trying to mock pg for unit tests. they're used to gather information about the pages you visit and how many clicks you need to accomplish a task. Instead you would have to discover the SQL generated by the ORM and setup appropriate expectations. is made available from the callback, test the query and params being passed. In general you should have no more than one mock (possibly with several expectations) in a single test. The following function debounces another function - only when it has not been called for 100 milliseconds will it call the original function with the last set of arguments it received. This approach is less brittle than mocking a third party library and you get the benefit of faster tests too. which makes mocking much easier. You get a lot of functionality in the form of what it calls spies, stubs and mocks, but it can be difficult to choose when to use what. Note that it’s usually better practice to spy individual methods, particularly on objects that you don’t understand or control all the methods for (e.g. A mock will fail your test if it is not used as expected. Thankfully, we can use Sinon.js to avoid all the hassles involved. https://github.com/node-nock/nock. I'm already running integration tests on a real database anyway, it's just more of a hassle than if I could do some sort of mocking. Thanks to Sinon.JS’ time-bending abilities, testing it is easy: As before, Sinon.JS provides utilities that help test frameworks reduce the boiler-plate. expectation.resolves. Testing the Movie Service 7. “I don’t always bend time and space in unit tests, but when I do, I use Buster.JS + Sinon.JS”. Do you want the. Expect the method to be called exactly twice. After an insert, there is 1 more row than before. There's a lot of functionality to mock in both but I think ultimately mocking the database later would be easier. Learn more, We use analytics cookies to understand how you use our websites so we can make them better, e.g. What is a Stub? Mocks should only be used for the method under test. Anybody have success with this and can offer guidance please? Really, I'd like test that the connection Listing 3. I would be very, very interested in a good solution for the exact same use case as well! Learn more. With an in-memory database you are testing side effects, e.g. The Sinon example is … In every unit test, there should be one unit under test. Objectives 2. We use optional third-party analytics cookies to understand how you use GitHub.com so we can build better products. Now, you can instance the pool and using that reference, put a mock to catch calls to pool.query. I agree, you can only get so far with by replacing the driver with an ORM. How do you test the execution of your hand written SQL then? I tend to write a memory-store and a postgres-store and assert that they work correctly using a shared test. discussion. If it looks too laborous, you may like the fake server: Test framework integration can typically reduce boilerplate further. However, getting started with Sinon might be tricky. To test this, we create a fake with behavior: Conveniently, we can query fakes for their callCount, received args and more. Is there some "pseudo" code or simple example, how would pg-pool mock look like? It looks like this is a recommended approach with Sequelize too. If any expectation is not satisfied, an exception is thrown. Well what I meant by mocking the db layer when using an ORM was really more along the lines of testing side effects than testing interactions. I think what you're really saying is the purest approach would be if it were possible to use ORM models without a connection to any database. Testing Backbone applications with Jasmine and Sinon. To see what mocks look like in Sinon.JS, here is one of the PubSubJS tests again, this time using a method as callback and using mocks to verify its behavior. The whole point of using an ORM is to abstract away SQL so you don't have to think about it. I'm stuck since 3 days on the same issue : I'm building a AWS lambda that connect to a postgres database. Subsequent calls will overwrite the previously-specified set of arguments (even if they are different), so it is generally not intended that this method be invoked more than once per test case. Expect the method to be called with the provided arguments and possibly others. A stub is a spy with predetermined behavior.. We can use a stub to: Take a predetermined action, like throwing an exception; Provide a predetermined response; Prevent a specific method from being called directly (especially when it triggers undesired behaviors like HTTP requests) Restore the jQuery.ajax method after your test by calling sinon.restore() in your test runner’s after() function. Anybody have success with this and can offer guidance please? We can make use of its features to simplify the above cases into just a few lines of code. A stub is like a spy, but replaces the real function with behavior you specify. Checkout https://github.com/brianc/node-pg-pool - it's going to be the pool How far depends on the level of support the ORM provides. Creates an expectation without a mock object, which is essentially an anonymous mock function. All copyright is reserved the Sinon committers. Standalone test spies, stubs and mocks for JavaScript. The rule of thumb is: if you wouldn’t add an assertion for some specific call, don’t mock it. Expect the method to be called exactly thrice. 1. Successfully merging a pull request may close this issue. trying to mock pg for unit tests. @cressie176 An in memory driver is essentially a mock db layer. Attempting to mock the db layer when using an ORM doesn't sound like a great idea. Sign in Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Expect the method to be called with obj as this.”}. . Can you elaborate how pg-pool can help make mocking easier? You can always update your selection by clicking Cookie Preferences at the bottom of the page. Reply to this email directly, view it on GitHub Sequelize is sort of a leaky abstraction in that regard. As one commenter advises you can't then "break out" of the ORM and do something native . Have a question about this project? I wanted to mock this database for testing. Listing 3 shows how to create a spy. Verifies the expectation and throws an exception if it’s not met. Promise library instead of the global one when using expectation.rejects or Project Setup 5. sinon.mock(jQuery).expects("ajax").atLeast(2).atMost(5); jQuery.ajax.verify(); var expectation = sinon.expectation.create([methodName]); Creates an expectation without a mock object, which is essentially an anonymous mock function. @erikkrietsch : prior to node-pg-pool added to node-pg, you couldn't get a reference to the client object so that you could mock the query function call. An expectation instance only holds onto a single set of arguments specified with withExactArgs. Really, I'd like test that the connection is being called (once) with the correct arguments... then, once the client is made available from the callback, test the query and params being passed. It's a fair amount of work though. Expect the method to be called with the provided arguments and no others. An expectation instance only holds onto a single set of arguments specified with withArgs. For more information, see our Privacy Statement. I'm not a javascript dev so this code have probably some caveats but it works. We’ll occasionally send you account related emails. https://github.com/notifications/unsubscribe/AADDoeU9amkPAS3olB1Smpt17RjCWLucks5qN00egaJpZM4I6TrI. they're used to log you in. What I might be missing? Postgres) supports but available in-memory databases (like SQLite) don't. You are receiving this because you are subscribed to this thread. There's a subtle but important difference. Causes all expectations created from the mock to return promises using a specific But the problem with in memory dbs is when you're using features like JSON fields that your production db (e.g. A mock is like a fake function, but with expectations you specify, such as how many times the function is called and with what arguments. I was kind of hoping for a general way similar to how nock does it for http requests... Maybe time to write our own library... urg. GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. These docs are from an older version of sinon. Already on GitHub? If you want to control how your unit is being used and like stating expectations upfront (as opposed to asserting after the fact), use a mock. implementation in node-postgres very soon and doesn't rely on singletons With a mock db layer you are testing interactions, e.g. I'd also be very interested in mocking capabilities. Method name is optional and is used in exception messages to make them more readable. Copy link Quote reply ReinsBrain commented Jun 21, 2016. Mocks (and mock expectations) are fake methods (like spies) with pre-programmed behavior (like stubs) as well as pre-programmed expectations. I think what you're really saying is the purest approach would be if it were possible to use ORM models without a connection to any database. Learn more about the fake server. GORM had excellent testing support for example. You can call the resulting function as many times as you want, but the original function will only be called once: Testing this function can be quite elegantly achieved with a test fake: The fact that the function was only called once is important: We also care about the this value and arguments: The function returned by once should return whatever the original function returns. 3. While the preceding test shows off some nifty Sinon.JS tricks, it is too tightly coupled to the implementation. Works with any unit testing framework. When testing Ajax, it is better to use Sinon.JS’ fake XMLHttpRequest: The preceding example shows how flexible this API is. https://github.com/notifications/unsubscribe/AADDoeU9amkPAS3olB1Smpt17RjCWLucks5qN00egaJpZM4I6TrI In my code_base I have something similar to : Do you have any idea why I can't mock connect? Expectations implement both the spies and stubs APIs. Use a stub instead. @brianc I'm having a hard time connecting the dots. @cressie176 I see. Hopefully that helps! Sinon Setup 6. We use essential cookies to perform essential website functions, e.g. Expect the method to be called exactly once. Christian Johansen’s book Test-Driven JavaScript Development covers some of the design philosophy and initial sketches for Sinon.JS. is being called (once) with the correct arguments... then, once the client that db.query("SOME SQL", [ a, b, c ]) was invoked with the expected parameters. I create my own in-memory/array backed versions of the stores and ensure parity by running a shared test suite against them. Method name is optional and is used in exception messages to make them more readable. Specify the minimum amount of calls expected.