mocha-bd-contract

Behavior driven contract tests using mocha

Getting Started

• NodeJS and NPM should be installed on the local machine
• Install this library using the command

  npm install mocha-bd-contract
  
  # or if you prefer using yarn,
  
  yarn add mocha-bd-contract
  

Writing contracts

Contract tests in this repo are primarily focused on schema based validations. Whenever you call any api, it should exactly match a given JSON schema, and the schema can validate things line what all fields are possible, what their data types should be, what the data restrictions should be etc.

A sample contract test using schema validation would look like this:

    const { validate, initiate } = new Validator({
        suite: 'Users list API should return 6 users',
        app: { baseUrl: 'https://reqres.in/api' }
    })

    describe('Users API', async () => {
        await initiate()

        validate(() => ({
            given: 'I have at least one user in the system',
            when: 'I call the /users api',
            with: {
                url: '/users',
                method: GET
            },
            then: 'I should get a list of users',
            expect: {
                statusCode: 200,
                schema: 'users',
                fulfilsConditions: (response) => [
                    {
                        message: 'There are 6 users',
                        check: response.data.length === 6
                    }
                ]
            }
        }))
    })

Refer to the examples folder for sample tests

• Since this is basically a mocha project, the validate call should be wrapped in a describe and you can use the mocha hooks like before, after, beforeEach, afterEach etc.
• The expect block can validate multiple things
  • statusCode will validate if the response status code is matching
  • schema will validate if the response matches the schema. apm.assetbase.technical-object.list-success-response means the list-success-response.json file inside src/schemas/apm/assetbase/technical-object directory. So if you have the schema file in src/schemas/apm/some-app/some-sub-folder/some-schema.json, then, the schema syntax would be apm.some-app.some-sub-folder.some-schema
  • body will validate if the response body exactly matches the given object. Not recommended if the response body values keep changing
  • fulfilsConditions is a list of conditions that you can dynamically verify. The lambda has a parameter which will contain the API response.

Execution result

The execution result would lok something like this:

   ✔ #3071819151: Users list API should return 6 users
        GIVEN: I have at least one user in the system
        WHEN : I call the /users api
        THEN : I should get a list of users                                           (154ms)

    1 passing (155ms)