sinon-test

Sinon Test

Automatic sandbox setup and teardown for SinonJS

Why?

Instead of writing tedious setup and teardown code for each individual test case you can let Sinon do all the cleanup for you.

So instead of doing this (using Mocha syntax):

var spy1;
var spy2;

afterEach(() => {
    spy1.restore();
    spy2.restore();
});

it("should do something", () => {
    spy1 = sinon.spy(myFunc);
    spy2 = sinon.spy(myOtherFunc);
    myFunc(1);
    myFunc(2);
    assert(spy1.calledWith(1));
    assert(spy1.calledWith(2));
});

You could write just this

it(
    "should do something",
    test(function () {
        var spy1 = this.spy(myFunc);
        var spy2 = this.spy(myOtherFunc);
        myFunc(1);
        myFunc(2);
        assert(spy1.calledWith(1));
        assert(spy1.calledWith(2));
    })
); //auto-cleanup

Sinon will take care of removing all the spies and stubs from the wrapped functions for you. It does this by using sinon.sandbox internally.

Do notice that we use a function and not a arrow function (ES2015) when wrapping the test with sinon.test as it needs to be able to access the this pointer used inside of the function, which using an arrow function would prevent.

See the Usage section for more details.

Installation

via npm (node package manager)

$ npm install sinon-test

Usage

Node and CommonJS build systems

Once initialized, the package creates a context for your test based on a sinon sandbox. You can use this in a wrapped test function to create sinon spies, stubs, etc. After your test completes, the sandbox restores anything modified to its original value.

If your test function takes any arguments, pass then to the test wrapper after the test function. If the last argument is a function, it is assumed to be a callback for an asynchronous test. The test function may also return a promise.

See the sinon documentation for more documentation on sandboxes.

sinon-test instances need to be configured with a sinon instance (version 2+) before they can be used.

var sinon = require("sinon");
var sinonTest = require("sinon-test");
var test = sinonTest(sinon);
var assert = require("assert");

describe("my function", function () {
    var myFunc = require("./my-func");

    it(
        "should do something",
        test(function () {
            var spy = this.spy(myFunc);
            myFunc(1);
            assert(spy.calledWith(1));
        })
    ); //auto-cleanup
});

Direct browser usage

In place of the require statements indicated above, in the browser, you should simply reference the global sinonTest after including a script tag in your HTML:

<script src="dist/sinon-test.js"></script>

Or if you are in an ES6 Modules environment (modern browsers only), you only need to add an import statement:

<script type="module">
    import sinon from "./node_modules/sinon/pkg/sinon-esm.js";
    import sinonTest from "./node_modules/sinon-test/dist/sinon-test-es.js";
    const test = sinonTest(sinon);

    it(
        "should work",
        test(function () {
            pass();
        })
    );
</script>

API

const test = require("sinon-test")(sinon);

In order to configure the sandbox that is created, a configuration hash can be passed as a 2nd argument to sinonTest:

const test = require("sinon-test")(sinon, { useFakeTimers: false });

The only difference to the standard configuration object for Sinon's sandbox is the addition of the injectIntoThis property, which is used to inject the sandbox' props into the context object (this).

Backwards compatibility

Sinon 1.x used to ship with this functionality built-in, exposed as sinon.test(). You can keep all your existing test code by configuring an instance of sinon-test, as done above, and then assigning it to sinon like this in your tests:

sinon.test = test;