mithril-query


Query mithril virtual dom for testing purposes

Installation

npm install mithril-query --save-dev

Usage

You can run this tests serverside or use browserify and run them in browsers.

// simple module: simple.js
var m = require('Mithril');

module.exports = {
  controller: function() {},
  view: function(ctrl) {
    return m('div', [
      m('span', 'spanContent'),
      m('#fooId', 'fooContent'),
      m('.barClass', 'barContent')
    ]);
  }
};

// test for simple module: simple.test.js
var test = require('tape').test;
var simple = require('./simple');
var mq = require('mithril-query');

test('simple module', function(t) {
  t.test('controller', function(t) {
    t.equal(typeof simple.controller, 'function', 'should be a function');
    t.end();
  });
  t.test('view', function(t) {
    t.equal(typeof simple.view, 'function', 'should be a function');
    var output = simple.view(simple.controller());
    $output = mq(output);
    t.ok($output.has('span'), 'should create span node');
    t.ok($output.has('div > span'), 'child selectors \o/');
    t.ok($output.has('#fooId'), 'should create fooId node');
    t.ok($output.has('.barClass'), 'should create barClass node');
    t.ok($output.has(':contains(barContent)'), 'should create node with content barContent');
    t.ok($output.contains('barContent'), 'should create node with content barContent');
    t.end();
  });
});

Run the test with

tape simple.test.js

API

First call the view result with the mithril-query function. Then the result has the following methods:

first(selector)

Returns the first element that matches the selector.

find(selector)

Returns all elements that match the selector.

has(selector)

Returns true if any element in tree matches the selector, otherwise false.

contains(string)

Returns true if any element in tree contains the string, otherwise false.

If you need any other assertions, feel free to create an issue or pull request.

Should style assertions

Now you can use these nice assertions. They throw errors if they're not fullfiled.

// test for simple module: simple.test.js
var test = require('tape').test;
var simple = require('./simple');
var mq = require('mithril-query');

test('simple module', function(t) {
  t.test('view', function(t) {
    var output = simple.view(simple.controller());
    $output = mq(output);
    $output.should.have('span'); //asserts to have at least one span element
    $output.should.have(4,'.even'); //asserts to have four elements with class 'even'
    $output.should.have.at.least(4,'li'); //asserts to have at least four li-elements
    $output.should.not.have('#main'); //asserts to not have an element with id 'main'
    $output.should.contain('hi'); //asserts to contain the string 'hi'
    $output.should.not.contain('bye'); //asserts to not contain the string 'bye'
    t.end();
  });
});

Event triggering

It is also possible to trigger element events like onfocus and onclick and set values on <input>-fields. This allows you to write "integration tests" that run also on serverside.

var el = [
  m('input', {oninput: m.withAttr("value", name), value: name()})
  m('#eventEl', {
    onclick: onClickOfEventEl,
    onfocus: onFocusOfEventEl,
  })

mq(el).click('#eventEl'); // triggers onClickOfEventEl
mq(el).focus('#eventEl'); // triggers onFocusOfEventEl
mq(el).setValue('input', 'huhu') //sets name prop to 'huhu'

Auto Rendering

You can also use auto rendering like mithril does. If you call the query function with a module, it instantiates the controller and calls the view with it's result. When using one of the upper events, redraw of the view is automatically called.

Example:

  // module code
  var module = {
    controller: function() {
      var scope = {
        visible: true,
        toggleMe: function() { scope.visible = !scope.visible; }
      };
      return scope;
    },
    view: function(scope) {
      return m(scope.visible ? '.visible' : '.hidden', {
        onclick: scope.toggleMe
      }, 'Test');
    }
  };

  // actual test
  var $out = mq(module);
  $out.should.have('.visible');
  $out.click('.visible');
  $out.should.have('.hidden');
  $out.click('.hidden', null, true);
  $out.should.have('.hidden');

As you can see, you can prevent autoredraw by providing a true as last argument to click method. This also works for blur, focus and setValue.

keyboard events

It also supports key events

  $out.keydown('div', 'enter');
  $out.keydown('div', 27);

you can either use keycode or the keys name. Mapping is done with this lib. keyup, keypress are also supported.

manual redraw

You can also manually trigger redraw:

var $out = mq(module);
$out.should.have('.visible');
$out.redraw();

It's also possible to insert a view and a scope, just in case you don't follow the standard mithril pattern (controller/view)... like I do sometimes ;)

var scope = {
  isVisible: true;
}

var $out = mq(view, scope);
$out.should.have('.visible');
$out.click('.visible');
$out.should.have('.hidden');

If you need to access the rendered root element you can simply access it with

$out.rootEl

onunload-handling

If you use the auto-rendering feature mentioned above you might want to also call onunload to on the controller response after testing. We added a reference to the controller onunload function to the result of the mithril query function.

var module = {
  controller: function() {
    return {
      onunload: function() {
        //clean up stuff
      }
    };
  },
  view: function(scope) {
    // do what ever
  }
};

var $out = mq(module);
$out.onunload(); // calls upper defined onunload on the controller result

Selectors

We use cssauron as engine, so look there if you want to see, what's possible.