promise-me-framework

PromiseMe

Very minimalistic testing framework.

Installation

    npm install promise-me-framework

Usage

    const {describe} = require('promise-me-framework').core;
 
    let test = describe('my test\'s name', function({scope}) {
        console.log('hello');
        return scope;
    });
 
    let scope = {};
 
    test()(scope)
        .then(() => console.log('done'));

Basics

Main concept is to use promise chains. Like this:

given(LoginFeature(options), scope)
    .then(OpenPage('https://mycoolapp.com'))
    .then(FillInput({
        id: 'login',
        value: 'tester'
    }))
    .then(FillInput({
        id: 'password',
        value: getPassword('tester')
    }))
    .then(ClickButton('login'))
    .then(WaitForTitle('Welcome!'))
    .then(ReportSucces)
    .catch(ReportFailure);

Although it's not "real" code but you've got the idea.

Now here is simple testing scenario:

const {describe} = require('promise-me-framework').core;
 
// declaring scenario
describe('scenario', ({scope}) => scope)({})({i: 0})
 
    // declaring step
    .then(describe('i++', ({scope}) => {
        scope.i++;
 
        return scope;
     })())
 
     // handling scenario results and errors
    .then(() => console.log('done'))
    .catch(({error}) => console.log(error));
 

And lets make it more modular:

// declaring step
let Increment = describe('i++', ({scope}) => {  
    scope.i++;
 
    return scope;
});
 
let scenarioOptions = {};
let scenarioScope = {increment: 0};
 
// declaring scenario
describe('scenario', ({scope}) => scope)(scenarioOptions)(scenarioScope)
    .then(Increment())
 
    // handling scenario results and errors
    .then(() => console.log('done'))
    .catch(({error}) => console.log(error));

Asynchronous steps

We can make our simple scenario asynchronous.

In order to do so we have to return promise instead of $scope:

// declaring step
let Increment = describe('i++', ({scope}) => {  
    return new Promise(function(resolve, reject) {
        setTimeout(() => {
            scope.i++;
            resolve(scope);
        }, 2000);
    });
});

Defenitions options

parameters

We can pass parameters to step like this:

    .then(Increment(10))

And in order to access it within step definition we have to use params property of context:

let Increment = describe('i++', ({scope, params}) => {  
    scope.i += params;
});

Pretty much everything could be passed as a parameter to a step.

name

We can access description name using name property of context.

let Increment = describe('my description', ({name}) => {  
    console.log(name); // prints 'my description'
});

providers

Also we can provide some data to context using providers

let browser = getBrowser();
let openUrl = ({params, browser}) => browser.url(params);
 
let myTest = describe('open url', openUrl, {browser});

Note that provider will be accessible only in context of description where it was specified and won't be passed down unless it's done explicitly

Groups

We can also group steps like this:

let Before = describe('before', doSmthBefore);
let After = describe('after', doSmthAfter);
let Action = describe('action', performaction);
let Prepare = describe('prepare', doPreparations);
let Continue = describe('continue', doSmthElse);
 
// declaring group
let Group = describe('group', ({scope}) => {
    return Before()(scope)
        .then(Action())
        .then(After());
});

and then use as regular step defenition

.then(Prepare())
.then(Group())
.then(Continue())

Alias module

as you can see we have to invoke description with scope object as parameter in order to create promise chain

// declaring group
let Group = describe('group', ({scope}) => {
    return Before()(scope)
        .then(Action())
        .then(After());
});

it's perfectly fuctional but not quite clear what is happening here

we can fix this using alias module like so:

const {alias} = require('promise-me-framework').alias;
 
let given = alias;
let Group = describe('group', ({scope}) => {
    return given(Before(), scope)
        .then(Action())
        .then(After());
});

now group description can be red almost like plain english

Parallel module

we can also execute steps in parallel using paralle module

connect it like so:

const {parallel} = require('promise-me-framework').parallel;

and use like this:

.then(parallel(
    actionOne('some parameter'),
    actionTwo(),
    actionThree([1,2,3])
))
.then(({scope}) => someActions(scope))

note that all descriptions will share same scope object

parallel method will pass down an array of resolved promises, or will throw a rejection