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Mimik is a behavior-driven testing framework and UI automation platform. Similar to Cucumber, it enables Agile story-writing allowing all stakeholders to describe how software should behave in natural language.

Mimik focuses on simplicity and brings excitement to test writing. Tests follow a simple text structure to describe domain-specific behavior. This text structure is known as Guerkin:

Feature: Login
  In order to access the application
  As a registered user
  I need to be able to log in

  Scenario: Successful login
    Given I am a registered user
    When I enter my credentials and submit the login form
    Then I should see a welcome page

Mimik is built on top of some of the best open source projects available:

Mocha: BDD Testing framework.
Yadda: Advanced BDD and Gherkin Given/When/Then parser.
Chai: Assertion library.
Selenium: Webdriver based browser automation.

Main Features

  • BDD / Cucumber style, Feature based testing
  • Supports features written in multiple languages
  • Supports both Javascript and Coffeescript source files.
  • Unit and Functional Testing
  • Generate test source files "step definitions" automatically
  • Watch for file changes and run specific tests automatically
  • Supports multiple parallel test strategies
  • Supports cross-browser testing
  • Run functional tests on local browsers or cloud-based services
  • Rich HTML5 reports
  • Jira and Testrail integration
  • Install and run selenium drivers automatically.
  • More: views, junit output, annotation support, filtering by annotations,
  • Lastly, it's Free!


Quick Start
Command Usage


Node.js and NPM are required in order to install Mimik. NPM is packaged with Node.js, so it's typically installed as well. If not, you can still install it separately.

npm install mimik -g

The flag -g ensures that the mimik command is installed and accessible globally.

Quick Start

Create a folder structure for your test project as follows:

├─ features
└─ steps

Note: This structure is generally recommended, but not required.

Define your Feature

Features are the primary building blocks in Mimik. Here you describe the feature you want to test. Features will contain a title, an optional description to outline the business benefits and goals. A feature will be followed by one or multiple scenarios. Each scenario will contain a series of given/when/then steps.

create the file features/login.feature and add the following content to it.

Feature: Login
  In order to access my account on Github
  As a registered user
  I need to be able to log in

  Scenario: Successful login

    Given I am a registered user
    When I go to github.com
    And I enter my credentials and submit the login form
    Then I should see a welcome page

Generate the Step Definitions

Run the following command to generate an empty step definition file template.

cd tests
mimik generate features/login.feature

An interactive menu will guide you through the process. Select the option to save output to a file when prompted, as follows:

Feature file: tests/functional/features/todomvc.feature
Press Ctrl+C to abort

Choose output
  1. javascript (default)
  2. coffeescript
  ›  javascript

Specify the feature file language
  1. English (default)
  2. French
  3. Norwegian
  4. Polish
  5. Spanish
  ›  English

Generate output
  1. Display output (default)
  2. Save to a file
  ›  Save to a file

Specify a path:
  tests/steps/login-steps.js (default)
  › Saving to tests/steps/login-steps.js

The generated step definition file should look like this:

// Given I am a registered user
Given(/I am a registered user/, function(done) {
// When I go to github.com
When(/I go to github.com/, function(done) {
// And I enter my credentials and submit the login form
And(/I enter my credentials and submit the login form/, function(done) {
// Then I should see a welcome page
Then(/I should see a welcome page/, function(done) {

We will edit the generated files further down. For now, let's run the feature as is.

Run Mimik

Now that the feature is defined and the corresponding step definition file is generated, go ahead and run mimik from the tests folder.

mimik run

If all the steps above were executed properly, you will get the following output (output is colored):

 Found 1 feature
  Feature: Login  #tests/features/login.feature
  Tested in firefox

    Scenario: Successful login
       ✓ Given I am a registered user
       ✓ When I go to github.com
       ✓ And I enter my credentials and submit the login form
       ✓ Then I should see a welcome page

  ---------- ----------- ------------- -------- --------- -------- 
  Features   Scenarios   Total Steps   Passed   Skipped   Failed 
  ---------- ----------- ------------- -------- --------- --------
  1          1           4             ✓ 4      0         0      
  Completed 1 feature in 1.37s

Update the Step Defintions



You can access the full documentation here.

Command Usage

The Mimik command

  Usage: mimik [options] [command]


    run                    run feature tests found in the [target] path
    watch                  watch for file changes in the [target] path, then run feature tests
    generate               generate step definition templates for the specified feature file <path>


    -h, --help                  output usage information
    -V, --version               output the version number
    -c, --config <path>         specify an external config file
    -b, --browsers <names>      comma-delimited <names> of local browsers to use (chrome|firefox|ie|safari|phantomjs)
    -m, --match <pattern>       only run features matching <pattern>
    --match-invert              inverts --match results
    -T, --tags <names>          only run feature tests annotated with one of the comma-delimited tag <names>
    -E, --exclude-tags <names>  exclude feature tests annotated with one of the comma-delimited tag <names>
    -t, --timeout <ms>          set per-test timeout in milliseconds [10000]
    -s, --slow <ms>             `slow` test threshold in milliseconds [5000]
    -f, --failfast              stop running tests on the first encoutered failure or timeout
    --test-strategy <name>      `test` runs various tests in parallel. `browser` runs each test against mutiple browsers [test]
    --reporters <names>         comma-delimited report <names> to enable. available options: junit,html
    --report-path <path>        path for the generated reports
    --rerun <path>              rerun failed tests recorded in `failed.dat` from the last test run
    --debug                     enable debug logging
    --log <path>                output a log file to filename

  Run mimik [command] --help to see description and available options for a particular command

Options for the watch command

  Usage: watch [options] [path ...]


    -h, --help              output usage information
    -d, --watch-delay <ms>  Buffers multiple changes into a single run using a delay in milliseconds [500]

The Selenium Launcher command

Usage: wdlauncher [command]


    start                  start the selenium standalone server
    install                install or update missing selenium driver binaries
    status                 display the current available driver binaries


    -h, --help       output usage information
    --output <path>  path to the location of the binaries
    -p,--port <num>  optional port for the selenium standalone server
    --auto-install   auto install missing binaries before starting the selenium server
    --overwrite      force download existing binaries
    --debug          enable debug logging
    --log <path>     path including file name to create a file log


See the examples folder.


See here.


Simo Moujami




npm i mimik

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