Tool for Behavior Driven Development in Julia
Author erikedin
7 Stars
Updated Last
2 Years Ago
Started In
February 2018


Build Status codecov.io

BDD is an acronym for Behaviour Driven Development. It is a process for creating and verifying requirements, written in such a way that they can be executed as code. This package aims to be a tool for executing such requirements, and creating reports.

This package is in the early stages of development, and has only minimal functionality.


Specifications are written in the Gherkin format, such as

Feature: Making coffee

    Scenario: Making a cup of coffee
        Given that there is a cup in the coffee machine
         When the "Coffee" button is pressed
         Then the cup is filled with coffee

For each Given, When, and Then line, a corresponding method is written, which is executed when that line is reached.

using ExecutableSpecifications
using CoffeeMachine

hascoffee(cup::Cup) = cup[:coffee] > 0.0

@given "that there is a cup in the coffee machine" begin
    cup = Cup()
    machine = Machine()

    cupisinthemachine(machine, cup)

    context[:cup] = cup
    context[:machine] = machine

@when "the \"Coffee\" button is pressed" begin
    machine = context[:machine]

@then "the cup is filled with coffee" begin
    cup = context[:cup]
    @expect hascoffee(cup)

Feature files have extension .feature, and are stored in the features directory (see "Current state" for current limitations), and step definitions (the executable code) have the extension .jl and are stored in features/steps.

Example project

The project CoffeeMachine.jl is an example of how to use ExecutableSpecifications.jl.


Run the command line tool runspec.jl from the directory containing the features directory, or from the Julia REPL with

julia> using ExecutableSpecifications
julia> runspec()

See "Current state" for limitations.

Julia 0.7 and 0.6

The master branch for this package is now for Julia 0.7. All development will be for 0.7 going forward.

If you require this package for Julia 0.6, there is a branch julia-release-0.6. This is behind in features, and will only be updated on demand.

Current state

The package has minimal functionality, but is under active development.

These are some current limitations, that will be lifted as development progresses:

  • Reads feature and step definition files from a single hardcoded directory.

    Today only the directory features is searched for feature files. Step files are only read from features/steps/*.jl. Going forward, all feature files and all step files will be read of course.

  • Presenting the results of scenarios is very rudimentary.

  • No setup or teardown functions.

  • No variables in step definition strings

    One would like to be able to define a variable in a step definition like @given "some value {foo}" begin. Without this, scenario outlines may become difficult to use, since you have to define a separate step definition for each value used in the outline.


ExecutableSpecifications.jl is licensed under the Apache License version 2.0.