I am creating a form and I am trying to find a simple, elegant way of handling to see if all inputs exist.
Form = Ember.Object.extend({
// section 1
name: null,
age: null,
isABoolean: null,
// section 2
job: null,
numberOfSiblings: null,
isComplete: Ember.computed.and('_isSection1Complete', '_isSection2Complete'),
_isSection1Complete: function() {
var isPresent = Ember.isPresent;
return isPresent(this.get('name')) && isPresent(this.get('age')) && isPresent(this.get('isABoolean'));
}.property('name', 'age', 'isABoolean'),
_isSection2Complete: function() {
var isPresent = Ember.isPresent;
return isPresent(this.get('job')) && isPresent(this.get('numberOfSiblings'));
}.property('job', 'numberOfSiblings')
});
However, this doesn't seem to scale. My actual application will have many sections (over 20 sections).
I am looking into trying to create a re-usable computed property that fits my needs. Take for example the code of what I am going for:
Form = Ember.Object.extend({
// properties...
isComplete: Ember.computed.and('_isSection1Complete', '_isSection2Complete'),
_isSection1Complete: Ember.computed.allPresent('name', 'age', 'isABoolean'),
_isSection2Complete: Ember.computed.allPresent('job', 'numberOfSiblings')
});
I feel that this is a common case, but I'm failing to find the correct computed properties on how to execute this, so I would like to make my own.
Two questions:
Where's the best place to define the custom computed property? Can I just attach a function to Ember.computed?
Is there an easier way to solve this? I feel like I'm overlooking something simple.
As for Question #1,
You can define a custom computed helper in the App namespace. In this example, I created a new computed helper called allPresent that checks each property passed in against Ember.isPresent.
App.computed = {
allPresent: function (propertyNames) {
// copy the array
var computedArgs = propertyNames.slice(0);
computedArgs.push(function () {
return propertyNames.map(function (propertyName) {
// get the value for each property name
return this.get(propertyName);
}, this).every(Ember.isPresent);
});
return Ember.computed.apply(Ember.computed, computedArgs);
}
};
It can be used like this, per your example code:
_isSection2Complete: App.computed.allPresent(['job', 'numberOfSiblings'])
I adapted this from the approach here: http://robots.thoughtbot.com/custom-ember-computed-properties
As for Question #2, I can't think of a simpler solution.
I had to make a minor adjustment to Evan's solution, but this works perfectly for anyone else that needs it:
App.computed = {
allPresent: function () {
var propertyNames = Array.prototype.slice.call(arguments, 0);
var computedArgs = propertyNames.slice(0); // copy the array
computedArgs.push(function () {
return propertyNames.map(function (propertyName) {
// get the value for each property name
return this.get(propertyName);
}, this).every(Ember.isPresent);
});
return Ember.computed.apply(Ember.computed, computedArgs);
}
};
This can now be used as such:
_isSection2Complete: App.computed.allPresent('job', 'numberOfSiblings')
Related
The approach I figure out is this
Given(
`Step1`,
async function() {
const IwantToUseThisObj = {
A: 'a',
B: 'b'
}
this.IwantToUseThisObj = IwantToUseThisObj
}
)
Then(`Step2`, async function() {
IwantToUseThisObj = this.IwantToUseThisObj
})
but I am not sure it's the best practice or not, and if I need to use it a lot of time it looks very repetitive,
any better approach? I just want to use the value I use from the Given step
Yes, storing data in the world class for reuse is best practice with cucumber
The most reliable and accepted way of passing data between steps in a scenario is to use the scenario context or "world" object this. Here is an example:
Feature File
Feature: Passing data between steps
Scenario: Passing data
Given I set the value to "test"
Then the value should be "test"
Step Definitions
const { Given, Then } = require('cucumber');
const assert = require('assert');
Given('I set the value to {string}', function (value) {
this.value = value;
});
Then('the value should be {string}', function (value) {
assert.ok(this.value === value);
});
Online Example: https://testjam.io/?p=cHsYgzrkRiI9dmkm1IyR
JS-Interpreter is a somewhat well-known JavaScript Interpreter. It has security advantages in that it can completely isolate your code from document and allows you to detect attacks such as infinite loops and memory bombs. This allows you to run externally defined code safely.
I have an object, say o like this:
let o = {
hidden: null,
regex: null,
process: [
"this.hidden = !this.visible;",
"this.regex = new RegExp(this.validate, 'i');"
],
visible: true,
validate: "^[a-z]+$"
};
I'd like to be able to run the code in process through JS-Interpreter:
for (let i = 0; i < o.process.length; i++)
interpretWithinContext(o, o.process[i]);
Where interpretWithinContext will create an interpreter using the first argument as the context, i.e. o becomes this, and the second argument is the line of code to run. After running the above code, I would expect o to be:
{
hidden: false,
regex: /^[a-z]+$/i,
process: [
"this.hidden = !this.visible;",
"this.regex = new RegExp(this.validate, 'i');"
],
visible: true,
validate: '^[a-z]+$'
}
That is, hidden and regex are now set.
Does anyone know if this is possible in JS-Interpreter?
I’ve spent a while messing around with the JS-Interpreter now, trying to figure out from the source how to place an object into the interpreter’s scope that can be both read and modified.
Unfortunately, the way this library is built, all the useful internal things are minified so we cannot really utilize the internal things and just put an object inside. Attempts to add a proxy object also failed failed since the object just wasn’t used in a “normal” way.
So my original approach to this was to just fall back to providing simple utility functions to access the outside object. This is fully supported by the library and probably the safest way of interacting with it. It does require you to change the process code though, in order to use those functions. But as a benefit, it does provide a very clean interface to communicate with “the outside world”. You can find the solution for this in the following hidden snippet:
function createInterpreter (dataObj) {
function initialize (intp, scope) {
intp.setProperty(scope, 'get', intp.createNativeFunction(function (prop) {
return intp.nativeToPseudo(dataObj[prop]);
}), intp.READONLY_DESCRIPTOR);
intp.setProperty(scope, 'set', intp.createNativeFunction(function (prop, value) {
dataObj[prop] = intp.pseudoToNative(value);
}), intp.READONLY_DESCRIPTOR);
}
return function (code) {
const interpreter = new Interpreter(code, initialize);
interpreter.run();
return interpreter.value;
};
}
let o = {
hidden: null,
regex: null,
process: [
"set('hidden', !get('visible'));",
"set('regex', new RegExp(get('validate'), 'i'));"
],
visible: true,
validate: "^[a-z]+$"
};
const interprete = createInterpreter(o);
for (const process of o.process) {
interprete(process);
}
console.log(o.hidden); // false
console.log(o.regex); // /^[a-z]+$/i
<script src="https://neil.fraser.name/software/JS-Interpreter/acorn_interpreter.js"></script>
However, after posting above solution, I just couldn’t stop thinking about this, so I dug deeper. As I learned, the methods getProperty and setProperty are not just used to set up the initial sandbox scope, but also as the code is being interpreted. So we can use this to create a proxy-like behavior for our object.
My solution here is based on code I found in an issue comment about doing this by modifying the Interpreter type. Unfortunately, the code is written in CoffeeScript and also based on some older versions, so we cannot use it exactly as it is. There’s also still the problem of the internals being minified, which we’ll get to in a moment.
The overall idea is to introduce a “connected object” into the scope which we will handle as a special case inside the getProperty and setProperty to map to our actual object.
But for that, we need to overwrite those two methods which is a problem because they are minified and received different internal names. Fortunately, the end of the source contains the following:
// Preserve top-level API functions from being pruned/renamed by JS compilers.
// …
Interpreter.prototype['getProperty'] = Interpreter.prototype.getProperty;
Interpreter.prototype['setProperty'] = Interpreter.prototype.setProperty;
So even if a minifier mangles the names on the right, it won’t touch the ones on the left. So that’s how the author made particular functions available for public use. But we want to overwrite them, so we cannot just overwrite the friendly names, we also need to replace the minified copies! But since we have a way to access the functions, we can also search for any other copy of them with a mangled name.
So that’s what I’m doing in my solution at the beginning in patchInterpreter: Define the new methods we’ll overwrite the existing ones with. Then, look for all the names (mangled or not) that refer to those functions, and replace them all with the new definition.
In the end, after patching the Interpreter, we just need to add a connected object into the scope. We cannot use the name this since that’s already used, but we can just choose something else, for example o:
function patchInterpreter (Interpreter) {
const originalGetProperty = Interpreter.prototype.getProperty;
const originalSetProperty = Interpreter.prototype.setProperty;
function newGetProperty(obj, name) {
if (obj == null || !obj._connected) {
return originalGetProperty.call(this, obj, name);
}
const value = obj._connected[name];
if (typeof value === 'object') {
// if the value is an object itself, create another connected object
return this.createConnectedObject(value);
}
return value;
}
function newSetProperty(obj, name, value, opt_descriptor) {
if (obj == null || !obj._connected) {
return originalSetProperty.call(this, obj, name, value, opt_descriptor);
}
obj._connected[name] = this.pseudoToNative(value);
}
let getKeys = [];
let setKeys = [];
for (const key of Object.keys(Interpreter.prototype)) {
if (Interpreter.prototype[key] === originalGetProperty) {
getKeys.push(key);
}
if (Interpreter.prototype[key] === originalSetProperty) {
setKeys.push(key);
}
}
for (const key of getKeys) {
Interpreter.prototype[key] = newGetProperty;
}
for (const key of setKeys) {
Interpreter.prototype[key] = newSetProperty;
}
Interpreter.prototype.createConnectedObject = function (obj) {
const connectedObject = this.createObject(this.OBJECT);
connectedObject._connected = obj;
return connectedObject;
};
}
patchInterpreter(Interpreter);
// actual application code
function createInterpreter (dataObj) {
function initialize (intp, scope) {
// add a connected object for `dataObj`
intp.setProperty(scope, 'o', intp.createConnectedObject(dataObj), intp.READONLY_DESCRIPTOR);
}
return function (code) {
const interpreter = new Interpreter(code, initialize);
interpreter.run();
return interpreter.value;
};
}
let o = {
hidden: null,
regex: null,
process: [
"o.hidden = !o.visible;",
"o.regex = new RegExp(o.validate, 'i');"
],
visible: true,
validate: "^[a-z]+$"
};
const interprete = createInterpreter(o);
for (const process of o.process) {
interprete(process);
}
console.log(o.hidden); // false
console.log(o.regex); // /^[a-z]+$/i
<script src="https://neil.fraser.name/software/JS-Interpreter/acorn_interpreter.js"></script>
And that’s it! Note that while that new implementation does already work with nested objects, it may not work with every type. So you should probably be careful what kind of objects you pass into the sandbox. It’s probably a good idea to create separate and explicitly safe objects with only basic or primitive types.
Have not tried JS-Interpreter. You can use new Function() and Function.prototype.call() to achieve requirement
let o = {
hidden: null,
regex: null,
process: [
"this.hidden = !this.visible;",
"this.regex = new RegExp(this.validate, 'i');"
],
visible: true,
validate: "^[a-z]+$"
};
for (let i = 0; i < o.process.length; i++)
console.log(new Function(`return ${o.process[i]}`).call(o));
Hi may be interpretWithinContext look like something like that ?
let interpretWithinContext = (function(o, p){
//in dunno for what you use p because all is on object o
o.hidden = (o.hidden === null) ? false : o.hidden;
o.regex = (o.regex === null) ? '/^[a-z]+$/i' : o.regex;
console.log(o);
return o;
});
https://codepen.io/anon/pen/oGwyra?editors=1111
Im trying to store the stats of 'this' in my javscript object so that later on in my application I can return 'this' to a previous state. I thought I could accomplish using a closure but so far I haven't successful. My idea was to do something like this
function SavedFeature() {
var self = this;
this.savedItem;
this.storeState = function() {
this.savedItem = storeClosure();
}
function storeClosure() {
var closure = self;
return function() {
return closure;
};
};
//other things the user can change...
}
so later on in my application if I needed to return to the point when I called storeState I could just do
//return the object I put in my closure
var backToNormal = savedFeature.savedItem();
that doesn't work though because any changes to my savedFeature object after I call storeState() are being reflected in the item im retrieving from called savedItem(). I'm guessing this is happening because closure is being set to a reference of self instead of copied to a new instance.
Is there anyway to store the state of my entire object in a closure like this or do I need to store this some other way.
The issue you are running into is that in js objects are passed by reference. This means that all changes performed on your object will apply to your obj.savedItem property.
Fix: Store a deep clone into obj.savedItem
this.storeState = function() {
this.savedItem = _.cloneDeep(this); // or _.clone(this, true);
}
cloneDeep is a lodash method, most js libs supply one of their own, e.g. jQuery's $.extend, etc.
You could easily roll your own deep clone function, look up the options on this thread.
A complete example with jQuery:
function SavedFeature() {
this.savedItem;
this.clone = function() {
return $.extend(true, {}, this);
},
this.storeState = function() {
this.savedItem = this.clone();
}
}
Doing it this way allows you adapt to different environments by changing your clone method as it is facading the used library method.
There are dozens of ways how to implement it. I will do just simple one. saving property.
Take into account if you want to save entire object you need to do deep copy of the object.
this is your feature:
function SavedFeature() {
this.savedItem = {'isNew': true};
this.stateMachine = new StateMachine();
}
this is some kind of state machine:
function StateMachine () {
var state = { 'isNew' : null};
function set(newState) {
state.isNew = newState.isNew;
}
function get() {
return state.isNew;
}
return {
get : get,
set : set
};
}
which, know how to store isNew property
and a working sample:
var savedFeature = new SavedFeature();
console.log(savedFeature.savedItem); // true by default
savedFeature.stateMachine.set(savedFeature.savedItem); // saving state.
savedFeature.savedItem.isNew = false; // modifying state
console.log(savedFeature.savedItem); // return false, because of statement above
var restoredState = savedFeature.stateMachine.get(); // restoring state
console.log(restoredState); // true
savedFeature.savedItem.isNew = restoredState.isNew;
console.log(savedFeature.savedItem); // true
you can adjust that code, and reach functionality whatever you need. hope that helps
I'm having a very hard time understanding how to setup an object that allows me to test my jQuery calls. I don't need to mock any Async calls or anything, just basic use. So let me set out my function that I want to test (truncated for simplicity):
listGamesCallback : function(data) {
var gameList = $("#gameList select");
gameList.empty();
$.each(data, function() {
var newOption = $('<option>', {value : this.gameId });
newOption.text(string);
newOption.data("isJoinable", isJoinable);
// Add it to the list
gameList.append(newOption);
});
}
I need to mock the jQuery here to unit test this method, but I'm unable to figure out how to do this in javascript. Even without jsMockito, I don't know how to create an object with the properties that jQuery has in this situation. Any help with this would be appreciated.
I am using jsTestDriver, jsHamcrest, jsMockito and jQuery. However a generalized approach to create a $ object that has these properties would be awesome as well. Thank you!
For those that asked, here is what I came up with that seemed to kinda work..but I don't understand why.
var saved$ = $;
var mockContruct = mockFunction();
var mockedGamelist = mock(jQuery);
var mockedOption = mock(jQuery);
mocked$ = (function() {
var test = function(name) {
var args = jQuery.makeArray(arguments);
return mockContruct.call(test, args);
};
$.extend(test, $);
// This is what confuses me. This worked, but it's wierd
// It allows me to use the regular jQuery functions like
// $.each, while returning mocked objects when selectors are used.
test.prototype.constructor = test;
return test;
})();
$ = mocked$;
when(mockContruct).call(anything(), hasItem(containsString("#gameList")))
.thenReturn(mockedGamelist);
when(mockContruct).call(anything(), hasItems(containsString("<option>"), both(object()).and(hasMember("value"))))
.thenReturn(mockedOption);
headerFunctions.listGamesCallback([ {
gameId : 1,
isWhitesTurn : false,
isGameOver : false,
whiteUserName : "foobar",
blackUserName : "barfoo"
} ]);
JsMockito.verify(mockedGamelist).empty();
JsMockito.verify(mockedGamelist).append(mockedOption);
$ = saved$;
Ok, here what I came up with that does the job with minimal setup. The .extend is completely necessary here so that the jQuery object is setup correctly. This allows you to mock the constructor to return mocked jQuery objects that you can use to run your tests on. As a spy, jQuery will work as expected in all situations except when you want it to do something else. Here it is:
TestCase("HeaderTest", {
testListGamesCallback : function () {
var saved$ = $;
$ = $.prototype.construct = jQuery.extend(spy(jQuery), jQuery);
var mockGameList = mock(jQuery);
when($)(containsString("#gameList")).thenReturn(mockGameList);
headerFunctions.listGamesCallback([ {
gameId : 1,
isWhitesTurn : false,
isGameOver : false,
whiteUserName : "foobar",
blackUserName : "barfoo"
} ]);
verify(mockGameList).empty();
verify(mockGameList).append(object());
$ = saved$;
}
});
The caveat to this solution is that mocking anything other than the constructor is a bit tricky. You will have to set each individual function that you want to mock, then program the behavior. So:
$.each = mockFunction();
when($.each)(...matchers...).thenReturn(...);
But it still allows for testing what you need to.
As an extension to alpian's answer, you can create DOM elements without having to add them to the page. Make your JS functions take the relevant elements as parameters:
listGamesCallback : function(data, gameListSelectElem) {
var gameList = $(gameListSelectElem);
...
and test them like so:
var fakeSelect = $('<select>'),
data = ...;
listGamesCallback(data, fakeSelect[0]);
equal(fakeSelect.find('option').length, 1, 'must have exactly 1 option');
...
The last line of code above is for qUnit. Take whatever you need, the point is to say you can pass a DOM element that was never added to the page and afterwards investigate that DOM element using jQuery to find whether it was manipulated right.
No sure if i understand what you mean but if you want to create 'data' for you example , this is the method i know:
var data = [ { id : 1 , name : 'foo' } , { id : 2, name : 'bar' ]
but - if you wanted to create a list of options, than you code needs a couple of fixes:
see http://jsfiddle.net/7MMap/
var data = [ { gameId : 1 , name : 'foo' ,isJoinable:true} , { gameId : 2, name : 'bar' ,isJoinable:false}]
listGamesCallback = function(data) {
var gameList = $("#gameList select")
.empty();
$.each(data, function(i,d) {
var newOption = $('<option>', {value : d.gameId })
.text(d.name)
.data("isJoinable", d.isJoinable);
// Add it to the list
gameList.append(newOption);
})
};
listGamesCallback(data);
Mocking jQuery is not what mocking is for. You should only ever be mocking your object's collaborators. jQuery is providing you with some utilities - it's not a collaborator and hence should not be mocked.
What you are collaborating with here is the DOM, or some intermediate object between your code and the DOM. data is a value object and can simply be created in your test as Avi suggests.
In my JS tests, i don't mock the DOM, i use the real DOM and am sure to tear down anything i created between tests and this seems to work pretty well.
I have hash defined like this:
var props = {
id: null,
title: null,
status: null
};
I'd like to define setter for status field (and only for it) doing it as following:
props.__defineSetter__("status", function(val){
//Checking correctness of val...
status = val;
});
But it doesn't work :(
So, what's the right way to do it?
Simple, you need to use
this.status = val;
Otherwise you are just setting an unrelated global variable status equal to val.
And as already noted, setters/getters are not implemented in IE.
Also, I'm not sure about how wise it is to have a setter that is the same name as the property it sets. Not sure if this will result in a conflict, but it does seem like a bad idea yes? Ideally the variable that would be set should be hidden in a closure
var props = {
id: null,
title: null
};
(function() {
var status;
props.__defineSetter__("status", function(val){
//Checking correctness of val...
status = val;
});
props.__defineGetter__('status', function() { return status; });
}());
This way, status is fully protected from direct access, which is the point of using setters and getters.
The first thing is what MooGoo has pointed out. But also, you can not assign a property setter to an object using the same name as an existing variable in the object.
So your code would have to be something arround this:
var props = {
id: null,
title: null,
hStatus: null,
};
props.__defineSetter__("status", function(v){
this.hStatus = v;
});
props.__defineGetter__("status", function(){
return this.hStatus;
});
[edit]
Yeah, MooGoo eddited his answer faster then time time I took to write this 8(.
This should work:
props.__setStatus__ = function(val) {
// Check correctness of val
this.status = val;
}
Usage:
props.__setStatus__('Alive');