Forem: Harit Himanshu

Working with Scala REPL mode

Harit Himanshu — Wed, 03 Jun 2020 16:30:25 +0000

One of the key benefits of working with Scala is to experiment with ideas using Scala's Read-Eval-Print-Loop (REPL) shell and get faster feedback. This video teaches how to work with the Scala REPL mode.

This video is part of a FREE course called First Steps in Scala. If you are interested in learning Scala, be sure to check out our FREE course at http://bit.ly/2MM4QAW

JWT.io is verifying the token based on empty secret and saying signature is verified

Harit Himanshu — Fri, 24 Apr 2020 18:50:55 +0000

JWT.io is verifying the token based on empty secret and saying signature is verified

Apr 24 '20 Comments: 1 Answers: 0

I am totally new to this, so please bear with my question if it's utterly stupid. I am learning how to verify signature using https://jwt.io

The following is what I am doing

Generated Public/Private Key Pair

Private Key

…

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How to test Java Classes using JUnit5 and Reflection API

Harit Himanshu — Sat, 18 Apr 2020 00:59:00 +0000

I have created a project which is intended to demonstrate the following using Java, Maven and JUnit5

If the Class exists in project.
If the class contains a method with a specific name
If a method is public, private
If a method contains parameters with specific types
If a method returns a specific type

And there could be more additions to such a list.

This project makes use of ReflectionUtils class from Junit5 and Java's Reflection API

The codebase and tests are available at GitHub

How do I test if a private method has a field with a name and a type?

Harit Himanshu — Sat, 18 Apr 2020 00:20:08 +0000

How do I test if a private method has a field with a name and a type?

Apr 18 '20 Comments: 1 Answers: 0

Here is the private method I am trying to test

    private int privateMethod(int[] numbers) {
        var sum = 0;
        for (int number : numbers) {
            sum += number;
        }
        return sum;
    }

I am doing this in Java 11

And following is my test using Junit5

import org.junit.jupiter.api.Test;
import org.junit.platform.commons.function.Try;

…

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Cannot stack multiple push notifications

Harit Himanshu — Fri, 10 Apr 2020 01:02:40 +0000

Cannot stack multiple push notifications

Apr 10 '20 Comments: 1 Answers: 1

I am working on a code to push notifications to the browser. My code to display notifications look like below

const imageWithTextNotification = (reg) => {
            // more options at https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerRegistration/showNotification#Syntax
            const options = {
                icon: "imgs/notification.png",

                // 07 - Notification with a body
                body: "Alert!! This is image notification",

…

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Why useEffect warns for the fields that I do not need to put in the dependencies array?

Harit Himanshu — Tue, 07 Apr 2020 19:27:56 +0000

Why useEffect warns for the fields that I do not need to put in the dependencies array?

Apr 7 '20 Comments: 4 Answers: 2

I have gone through the useEffect documentation and I do not understand why I get warning for every variable and function that I use inside useEffect, but I have no dependency on them.

Consider my useEffect here

const [updatedComm, setUpdatedComm] = useState<ICommunication>(props.comm)
const [isEditOn, setIsEditOn] = useState<boolean | false>(false)

…

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What does event.waitUntil do in service worker and why is it needed?

Harit Himanshu — Sun, 05 Apr 2020 17:45:16 +0000

What does event.waitUntil do in service worker and why is it needed?

Jun 18 '16 Comments: 1 Answers: 1

MDN suggests that you do the following to create and populate service worker cache:

this.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open('v1').then(function(cache) {
      return cache.addAll([
        '/sw-test/',
        '/sw-test/index.html',
        ... etc ...
      ]);
    })
  );
});

I do not understand that code. The waitUntil method is documented too, and it seems the code above is…

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JavaScript String toLowerCase and toUpperCase

Harit Himanshu — Thu, 19 Mar 2020 16:30:21 +0000

In this short video, you will learn how to change the JavaScript String to lower and upper cases using methods available on String constructors. We will use .toLowerCase() and .toUpperCase() methods.

The code sample is available at https://bonsaiilabs.com/javascript-string-lowercase-uppercase/

Subscribe for more videos on JavaScript with Visualization: https://www.youtube.com/channel/UC0yZBnRsD9JRqLXBkfGym0Q?sub_confirmation=1

Matching Numbers in JavaScript Strings using Regular Expressions

Harit Himanshu — Tue, 17 Mar 2020 16:00:42 +0000

Learn how to match number patterns such as phone numbers and credit cards in the unstructured text using JavaScript Strings

This video is a follow-up video for - Search a String by matching against a regex in JavaScript available at https://bonsaiilabs.com/javascript-regex-match-strings/

In this video, we will extract phone numbers and credit card data using regular expression and String.match available in JavaScript
The code sample is available at https://bonsaiilabs.com/javascript-regex-match-numbers/

Subscribe for more videos on JavaScript with Visualization: https://www.youtube.com/channel/UC0yZBnRsD9JRqLXBkfGym0Q?sub_confirmation=1

Search a String by matching against a regex in JavaScript

Harit Himanshu — Thu, 06 Feb 2020 18:00:12 +0000

Learn to match a String pattern inside another String using Regular Expression in JavaScript.

This video teaches a use case on where this scenario might be useful and how regular expressions can help solve the problem
We will use the String.match API in combination with regular expression in this video.

We will also look at the API documentation available on Mozilla Developer Network (MDN)

The code sample is available at https://bonsaiilabs.com/javascript-regex-match-strings/

How can I test whether a for loop is available in the Class?

Harit Himanshu — Sun, 26 Jan 2020 00:53:23 +0000

How can I test whether a for loop is available in the Class?

Jan 26 '20 Comments: 5 Answers: 1

Let me explain the use case first.

The use case is that a learner learning java is following a set of written instructions and using automated tests (read JUnit), I want to test whether they have successfully implemented the instruction.

Things that I need to find out programmatically, for…

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Where can I find the complete list of items added to MicroTask Queue?

Harit Himanshu — Tue, 21 Jan 2020 17:04:17 +0000

Where can I find the complete list of items added to MicroTask Queue?

Jan 21 '20 Comments: 1 Answers: 1

I am following up after reading the post Difference between microtask and macrotask within an event loop context

The examples posted are

macrotasks: setTimeout, setInterval, setImmediate, requestAnimationFrame, I/O, UI rendering
microtasks: process.nextTick, Promises, Object.observe, MutationObserver

I am wondering where can I find the list of tasks added to the microtask…

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