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    describe

    1.2.0 • Public • Published

    describe

    Describe provides a simple method for testing asynchronous and synchronous code within JavaScript projects.

    API Documentation

    describe

    describe( groupName, tests[, options] );

    Arguments

    • groupName (string): A human-readable description of the test group.
    • tests (object): An object made up of human-readable test descriptions as keys and functions to run as tests. Tests functions will be given access to this.expect.
    • options: Configuration options. Possible values:
      • timeout (int): The max amount of time in milliseconds to wait for a test to run before timing out.
      • callbackMode (string): if set to 'node', this.expect will treat the first argument to the callback as an error and the second argument as the result.

    describe.config

    describe.config( key, value )

    Sets the global configuration for tests.

    Synchronous Assertions

    this.expect( subject, expected )

    Arguments

    • subject (mixed): the actual result.
    • expected (mixed): the expected result.

    Example

    describe("assertions", {
        'basic synchronous expectation': function() {
            this.expect(42, 42);
        }
    });

    Asynchronous Assertions

    By passing this.expect as the callback parameter to an asynchronous function, describe will know to wait for the result of the operation before checking to see if the result matches what was expected.

    this.expect( expected )

    Basic Callbacks

    function addNumbersAsync(a, b, callback) {
        callback(a+b);
    }
     
    describe("assertions", {
        'basic asynchronous expectation': function() {
            addNumbersAsync(2, 2, this.expect(4));
        }
    });

    Node.js-style (e, data) Callbacks

    function addNumbersAsync(a, b, callback) {
        callback(null, a+b);
    }
     
    describe("assertions", {
        'basic asynchronous expectation': function() {
            addNumbersAsync(2, 2, this.expect(4));
        }
    }, { callbackMode: 'node' });

    Promises-style Callbacks

    function addThingsPromise() {
        var n = 0;
        for (var i in arguments) n+=arguments[i];
        return {
            then: function(success, failure) {
                success(n);
            }
        };
    }
     
    describe("promise callback style", {
        'promises-style addition': function() {
            this.expect(addThingsPromise(2, 2), 4);
        }
    }, {
        callbackMode: 'promises'
    });

    describe.getResults

    An asynchronous method. Calls back with the results of all tests described up to that point. You should probably wait until you're done defining tests to call this.

    Example Results

    { 
        passed: 1,
        total: 2,
        results: {
            "sample test group": {
                passed: 1,
                total: 2,
                results: {
                    "this test passed because its error is null": null,
                    "this test failed because there's an error": "Error or message"
                }
            }
        }
    }

    describe.logResults

    Gets the results and outputs them either to the DOM or the console.

    Test Hooks

    Each test group supports beforeEach, afterEach, beforeAll, and afterAll as test hooks.

    Example

    (function() {
     
        var arr = [], bowties;
     
        describe('array stuff', {
            beforeAll: function() {
                bowties = 'cool';
            },
            beforeEach: function() {
                arr = arr.concat(1,2,3);
            },
            afterEach: function() {
                arr = [];
            },
            afterAll: function() {
                tests = null;
            },
            'bowties are cool': function() {
                this.expect(bowties, 'cool');
            },
            'arrays have three things': function() {
                this.expect(arr.length, 3);
                arr.push(5);
            },
            'arrays still have three things': function() {
                this.expect(arr.length, 3);
            }
        });
     
    }());

    Keywords

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    Install

    npm i describe

    DownloadsWeekly Downloads

    2,199

    Version

    1.2.0

    License

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    Last publish

    Collaborators

    • yuffster