ddt.js

Simple but powerful JSON-like data-driven unit testing utility

Features

• Optimized for testing synchronous functions
• Tests are defined in JSON-like code data, alongside main code, enabling flexibility

Installation

npm install -g --save ddt-js

Module Usage

var ddt = require('ddt-js);

let sayHello = function(person){
    if (!person && person !== false)
        throw "invalid person";
    else
        return "Hello " + person;
}

ddt.test({
    title: "test sayHello() with actual person",
    unit: sayHello,
    getArgs: function() { return ["World"]; },
    getExpected: function() { return "Hello World"; }
})

output:

{
    title: "test sayHello with actual person",
    unit: "sayHello()",
    args: ["World"],
    expected: "Hello World",
    actual: "Hello World",
    passed: true
}

Command-Line Usage

ddt --src foo/bar/src --dest foo/bar/test --ext .test.result --test-info-key testInfo

The command line options are:

• src: source module files directory; defaults to the current working directory
• dest: destination directory for test results; defaults to the current working directory
• ext: extension for test result files
• test-info-key: specifies the property of each source module that contains the test information.

The ddt command-line assumes each file in the source glob defines a single module together with its test information. To be testable, the module definition must export a test information object (by default named "testInfo") that specifies the folowing members:

• cases: An array of test cases of the form:

    { 
        title: "test title",
        description: "test description",
        unit: function(){}, // the function being tested
        getArgs: function(){ return []}, // return array of arguments to be passed to unit
        getConvertedActual: function(actual){ return actual }, // optional function to convert actual value before comparison
        getExpected: function(){}, // return expected value of test
        getComparison: function(expected, actual) { return expected === actual; } // optional function to compare expected and actual
    }

• getContext(): a function that returns a global context object for all the test cases in the module
• defaultUnit: the default function to be tested. Each test case in the module can specify its own unit to override this value, but in situations where most of the test cases are testing the same unit, that unit can be specified here

Example module for command-line ddt testing:

module.exports.sayHello = function(person){
    if (!person && person !== false)
        throw "invalid person";
    else
        return "Hello " + person;
}

module.exports.testInfo = {
    defaultUnit: sayHello,
    getContext: function() { return null; },
    cases: [
        {
            title: "sayHello() return correct output with actual person",
            getArgs: function() { return ["World"]; },
            getExpected: function() { return "Hello World"; }
        },
        {
            title: "sayHello() return correct error with null person",
            getArgs: function() { return [null]; },
            getExpected: function() { return "invalid person"; }
        }
    ]
    
})