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Constructor in Strict Mode [closed]

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I've been searching a lot for an answer to this REALLY simple question, but I cannot find it:
" How to create constructors in strict mode ? "
fetch(`https://restcountries.com/v3.1/name/${country_name}`, )
.then(response => {
if(! response.ok)
throw new MyError(response.statusText, response.status)
[...]
.catch(err => {
renderNotFound(err.message, err.code)
[...]
class MyError {
constructor(message, code) {
this.message = message
this.code = code
}}
I know the .this keyword resolves to undefined in strict node. So how can we work around it to create constructors?
Thanks in advance
EDIT: fixed a missing } in the class MyError

How to create constructors in strict mode?
When using class syntax, constructor functions are always in strict mode, because the body of a class is always strict. (Most new kinds of scope defined in ES2015+ are strict by default.)
I know the .this keyword resolves to undefined in strict node. So how can we work around it to create constructors?
No workaround required. this is set to undefined when you call a function without doing anything to set this (for example: example()). When you use new, this is set to an instance of the thing being created before your constructor code is called (in a base constructor) or when you call super(/*...*/) (in a subclass constructor). (And when you do something else to set this (like example.method() or method.call(example)), this is set just like it is in loose mode.) Example:
class MyError {
constructor(message, code) {
this.message = message
this.code = code
}
}
const x = new MyError("Ooops!", 42);
console.log(x.message); // Ooops!
console.log(x.code); // 42
Just to underscore the point that class bodies are in strict mode by default:
class MyError {
// Code here is strict, even though the script
// context around it isn't
static example() {
console.log(this === undefined);
}
}
const loose = {
// Code here is loose like the script context around it
example() {
console.log(this === undefined);
}
};
let f;
f = MyError.example;
f(); // true
f = loose.example;
f(); // false
In a comment you've suggested that code doesn't work in strict mode. It should, assuming you have a } on your class. It does in this fiddle (can't do fetch in stack snippets, sadly):
"use strict";
class MyError {
constructor(message, code) {
this.message = message
this.code = code
}
}
fetch(`/this-will-404`, )
.then(response => {
if(! response.ok)
throw new MyError(response.statusText, response.status)
})
.catch(err => {
renderNotFound(err.message, err.code);
});
function renderNotFound(message, code) {
console.log(`Not found: ${message} ${code}`);
}

How to migrate javascript file into typescript [closed]

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I need some help/suggestion on how can I able to migrate javascript file into typescript.
I am very early beginner on typescript.
I have gone through many tuorials as well https://www.typescriptlang.org/docs/handbook/classes.html but not able to do so .
Any help/suggestion would be very helpful.
//eaxmple code
(function() {
"use strict";
var CONSTANTS = {
PROTOCOL_SECURE : "https://",
PROTOCOL : "http://"
};
var constantNew = window.constantNew = function() {};
constantNew.prototype.init = function(params) {
this.lobby = params.lobby;
this.bSecure = !!params.bSecure;
};
constantNew.prototype.getPMAInfo = function() {
var url = (this.bSecure? CONSTANTS.PROTOCOL_SECURE:DEMETER_CONSTANTS.PROTOCOL)
+this.lobby
+CONSTANTS.URL_GETPMAINFO_PATH;
return Promise.resolve({baseUrl:url})
.then(callDemeter) // just a call to demeter to get PMA Info
.then(decoratePmaData) // a small decorator
.catch(checkGeneralFailure("getPMAInfo"));// final error handler
};
constantNew.prototype.hangoutAuthenticate = function(args) {
var baseUrl = (this.bSecure? DEMETER_CONSTANTS.PROTOCOL_SECURE:DEMETER_CONSTANTS.PROTOCOL)
+this.lobby
+DEMETER_CONSTANTS.URL_HANGOUT_AUTHENTICATE;
return Promise.resolve()
.then(requestChallengeFn(baseUrl)) // request challenge (higher order function to get the workflow function)
.then(authenticatePartialApplication(baseUrl, args.account, args.password, args.bValidateByConfCode)) // try first first auth round or fail
.then(decorateHangoutAuthResult) // decorate result to return
.catch(checkGeneralFailure("hangoutAuthenticate")); // final error handler
function decorateHangoutAuthResult(authResult) {
return {
strWebroom: authResult.webroom[0].webroomcode,
strWebroomResource: authResult.webroom[0].resource,
strDemeterAuthToken: authResult.AUTHTOKEN,
strAudioConfCode: authResult.webroom[0].audioconferencecode
};
}
};
}());

There's no direct way of doing it unfortunately (i.e., via a script or some utility). Typescript provides the following guide to get you running there: https://www.typescriptlang.org/docs/handbook/migrating-from-javascript.html
That being the case, it might be better to start over. There's several options such as the Typescript Node Starter project in Github: https://github.com/microsoft/TypeScript-Node-Starter

Testing Error on node.js function with Mocha [closed]

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Closed 7 years ago.
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With Node.js installed and testing with mocha,
I have two files, numbers.js and test.js in the same directory
Following the top answer: What is the purpose of Node.js module.exports and how do you use it?
numbers.js
var myFunc = function myFunc() {
return 10;
};
exports.myFunc = myFunc;
test.js
var assert = require('assert');
var numbers = require('./numbers');
describe('numbers', function() {
it('first function returns 10', function() {
var result = numbers.myFunc;
assert.equal(result, 10);
});
});
But when running $ mocha it returns the error:
AssertionError: [Function: myFunc] == 10
What am I doing wrong?

You need to call your myFunc function. Add the parens
describe('numbers', function() {
it('first function returns 10', function() {
var result = numbers.myFunc(); <<<<<<
assert.equal(result, 10);
});
});

First of all, Inspect your numbers module is properly required or not.
var numbers = require('../numbers'); // Check path of file numbers.js
If yes, write :
var result = numbers.myFunc(); // your module exports 'myFunc' property not 'myfunc'
assert.equal(result, 10); // your function return '10' instead of '1'

Is that possible to call module factory from other javascript [closed]

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Closed 8 years ago.
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I have two javascript files separately and I want to retrieve one from another. So, I created Module factory as below;
var module = angular.module('test',[]);
module.factory('$result', function() {
var data = {something:"somewhere"};
return data;
});
and I want to called from other file. For now, I settled as below;
var module = angular.module('myApp', ['test']);
module.controller('NearestController', function($test) {
console.log(test);
});
Which part of me doing wrong ?? please help me and I'm newbie in angular

It should be like that ..
var module = angular.module('test',[]);
module.factory('Result', function() {
var data = {something:"somewhere"};
return data;
});
You can call like that.
var module = angular.module('myApp', ['test']);
module.controller('NearestController', function(Result) {
console.log(Result);
});
Hope it might be work.

As the comments suggested, you inject your dependencies as parameters in your controller function:
var module = angular.module('myApp', ['test']);
module.controller('NearestController', function($result) {
console.log(test);
});

Revealing module implicity calling an internal function - is this a "smell" [closed]

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I'm trying to improve my javascript and have been using the revealing module pattern to good effect but I noticed that code in the module not in a function or the return is executed on creation have utilised this, such as:
var MyModule = function ($) {
setUp();
function setUp() {
// execute code to be run when module created
}
function doStuff() {
}
return {
doStuff: doStuff
}
}
I can see this is creating a form of constructor for the function which relies on it being called by var myModule = new MyModule(jQuery).
Any feedback on the rights or wrongs of this appreciated.