How to handle internal error in Spring for GraphQL
This is an extension to the articles - Getting started with Spring and GraphQl and Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester....
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Java
Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester
Following my previous article on getting started with spring and graphql, let’s look at how we can do integration testing on the graphql spring boot applicat...
Getting started with Spring and GraphQl
The most common way of creating APIs is using REST (Representational State Transfer), of which we make use of the http verbs (POST, GET, PUT, DELETE) to stat...
Quick start tutorial on MicroServices with Spring Cloud Netflix Eureka
In traditional application development, we have everything under a single project. But when the project gets bigger, involving multiple teams, it might make ...
How to deal with nested entities in Spring controllers
Creating a webservice with Spring is almost trivial, you usually won’t go wrong by following the tutorials. However, things can get tricky sometimes when you...
Getting started Spring Boot Application
Frameworks have made developing backend applications much easier compared to doing everything manually. For example, we no longer need to deal with the http ...
Simulating Rubik Cube Actions with Java
Let’s work on something fun today, simulating a rubik’s cube. This is the precursor to my next topic to provide the solution to solve rubik’s cube. Modell...
Creating and filling a 2D array using Functional Programming in Java
Java stream is a wonderful addition since Java 8 to create and manipulate arrays/lists with ease. However, as other new programming languages can do all the ...
Java Arrays Lists & Streams Reference
// Initialize Arrays Integer[] integerArray = {1, 2, 3, 4, 5}; System.out.println(Arrays.toString(integerArray)); // Initialize List List<Integer> int...
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
Error message not showing from Spring ResponseStatusException
A little discovery I found recently. My error messages are not showing as intended. @PostMapping @ResponseStatus(HttpStatus.CREATED) fun createAccount(@Requ...
No tests found when running Cucumber JUnit
Sometimes it can be pretty frustrating when the error message doesn’t show the root cause of the problem, usually that’s because it is not straightforward wh...
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
Mutation testing with Pitest
Beyond just ensuring every line of code is executed with Code Coverage test, there is another way to ensure the test cases written are adequate, and that is ...
Code coverage for Java - Jacoco
Testing is a very important process in software engineering to ensure the quality of the code we write, and we can ensure testing is adequate by doing code c...
Using Lombok in Intelli J
Lombok is a pretty neat tool when coding in Java, allowing me to save time writing repetitive codes. But when you are installing it in a new project or in a ...
Adding a catalog of Maven Archetypes in Intelli J
Archetypes make it easy to scaffold a project, but remembering all the archetypes available and using the command line to activate it can be challenging to r...
Angular
Testing MatOptionHarness in MatSelectHarness
Reminder to self: When trying to get the options in the MatSelectHarness in Angular Material, you need to simulate a click on the MatSelectHarness - await se...
How to pass data from angular to css
I am creating an angular template whereby I can create forms from a data file automatically, such as a json or yaml. For displaying on the monitor screen, ...
How to use router-store in NgRx
What is the purpose of the router-store in NgRx? As explained in my previous article on NgRx, the purpose of NgRx is to separate the data management part ...
How to apply Material theme colors for your Angular Component
TLDR; Create a @mixin to receive the $theme as a parameter, so that you can get the colors you need from the $theme and apply it to your css selectors. The...
Defining your own theme in Angular Material
Having your own theme in your web application is essential to make it look professional. Imagine using the default color themes provided from the framework y...
How to test NgRx
Ngrx is a framework for angular that helps to separate the backend logic from the frontend, making the code easier cleaner. To know more about how it works...
NgRx Explained
Often times, when our angular applications grows, our code become quite messy to follow. We have multiple components, referencing a myriad number of servic...
How to test HttpClient in Angular
This is a simple method to call http using the HttpClientModule. getBooks(): Observable<Book[]>{ return this.http.get<Book[]>(BooksService.b...
How to use environment variable in Angular
Angular automatically creates 2 files - environment.ts and environment.prod.ts, in the environment folder when the project is first created. Both of them has...
How to do navigation in Angular
When you create a new angular app using ng new <application name>, the first question you get asked is ? Would you like to add Angular routing? (y/N). ...
Getting started with Angular
What is Angular? In my opinion, Angular is the platform and framework for building your own customized html tags. While html has a fixed set of tags (e.g. &...
Upgrade Angular project from v11 to v13
I’m slow…. It’s been a while since I last touched my Angular repository, that was created in early 2020, running on Angular 11. When I just went back to it y...
Simple http server to test Angular production build
After creating the production build for an Angular project with ng build --prod, the output is a folder of html and javascript, which will only work if you s...
How to publish Angular component to NPM
There are some requirements that a module needs to fullfil before it can be published to npm. For example, you’ll need a main field in your package.json http...
A little primer to start off with Angular
Angular is a javascript framework for creating websites. Instead of using regular html tags (like div, span, form, input), Angular lets you define new html t...
Code coverage in Angular
Unit testing has been the quintessential way to ensure whatever code we add to our program doesn’t break anything, but how do we tell if the unit tests are a...
Spring
How to deal with nested entities in Spring controllers
Creating a webservice with Spring is almost trivial, you usually won’t go wrong by following the tutorials. However, things can get tricky sometimes when you...
How to create a user in Spring after login with OpenID Connect
Following my last article on creating OpenID Connect login with Spring Boot, we shall now enhance the application to create a user in our MongoDB database fo...
OpenID Connect login with Spring Boot
OpenID Connect (OIDC) is an identity authentication protocol, using the mechanism of OAuth2, to allow applications to delegate their login function to identi...
Getting started Spring Boot Application
Frameworks have made developing backend applications much easier compared to doing everything manually. For example, we no longer need to deal with the http ...
Upgrade SpringDoc dependencies for Spring 3.0
In my previous article on how to add Swagger on Spring with Kotlin, the examples were built on Spring 2. With the introduction of Spring 3, there are some up...
How to get external configuration in Spring
Sometimes we have some configuration data that we need in our code, that can be changed periodically, like mail server information, proxy server, etc. We can...
Adding Swagger to Kotlin Spring
Spring makes it extremely easy to create REST api, but as a consumer of APIs, we need documentations to know what is available and how to use it. That’s wher...
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
Error message not showing from Spring ResponseStatusException
A little discovery I found recently. My error messages are not showing as intended. @PostMapping @ResponseStatus(HttpStatus.CREATED) fun createAccount(@Requ...
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
Cucumber testing on Spring Boot
Cucumber is a great way for users to automate acceptance testing, as it allows using somewhat natural language to define the test cases. With a little learni...
Spring Boot
How to handle internal error in Spring for GraphQL
This is an extension to the articles - Getting started with Spring and GraphQl and Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester....
Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester
Following my previous article on getting started with spring and graphql, let’s look at how we can do integration testing on the graphql spring boot applicat...
Spring boot testing with MongoDB using TestContainers
When we need to test our spring boot application that is running MongoDB, it will by default connect to the MongoDB instance with the connection details in o...
How to create custom validation annotation
When we have an application that collects inputs from users, we usually need to have some validation checks to ensure user inputs are within what is expected...
How to validate input in Spring Boot RestController
Validating user inputs is not a difficult task, but it is rather cumbersome. Although essential, having lots of validation checks in the code makes the code ...
How to do integration testing in Spring Boot Rest application
Unlike unit tests where we should be isolating the test to just the codes in the function we are testing, integration tests is meant to test the full spectru...
How to unit test rest controller in a Spring boot application
Spring provides the @WebMvcTest annotation for testing Spring MVC components, providing only the configuration relevant to the MVC tests and not the full aut...
How to test services in a Spring boot application
Unit testing services is easy, cause we don’t need to set up any application context in Spring, since the purpose of unit testing is just to isolate testing ...
Getting started Spring Boot Application
Frameworks have made developing backend applications much easier compared to doing everything manually. For example, we no longer need to deal with the http ...
Containerizing with Docker explained
After you have created your application, it is always nice to have it containerized so that it can be readily used whenever you need it, without having to cl...
Cucumber testing on Spring Boot
Cucumber is a great way for users to automate acceptance testing, as it allows using somewhat natural language to define the test cases. With a little learni...
Git
Resolve git SSL certificate problem on windows
While trying to push my project to Azure DevOps on my corporate windows machine, I got this error message when I am trying to push my code - SSL certificate ...
How to squash commits
Why do we need to squash commits Sometimes when we are working on a feature, we might forget to run all the tests before we commit, and we could get test fa...
How to fix a git rebase on a public master branch
What is Git Rebase The git rebase is a command in Git that allows you to modify the commit history of a branch by moving or combining a sequence of commits ...
Git detect dubious ownership in repository
When working in the corporate environment, we usually have a designated user space for each authenticated user on our computer. For example, in Windows, if...
Fix for filename too long in Git for Windows
If you are running git on windows, with a deeply nested folder structure in your code, you might get the error message - “Filename too long”. That is because...
How to rename a remote branch in Git
While working in a team, there are usually some naming conventions for the branches, like prefixing the branch with “feat/” for feature branch, or “fix/” for...
Harmonizing line breaks while working with different OS
When working in a team, someone will be using windows, while some will be on mac. Usually, it won’t be an issue, but windows and mac/linux has a different wa...
Stashing local configurations
In the project I’m working on, there are some local configurations (typically database connection strings) that I do not push to the git remote. This causes ...
Updating the remote to incorporate the new personal access token requirement on github
Recently github has discontinued the using of username and password - https://github.blog/2020-12-15-token-authentication-requirements-for-git-operations/. S...
Rescuing a branch that branches from the wrong branch
I am building a fix for the current release of a project, so the fix branch should branch out from the current master branch like this: However, as I was ...
Kotlin
Containerizing with Docker explained
After you have created your application, it is always nice to have it containerized so that it can be readily used whenever you need it, without having to cl...
How to get external configuration in Spring
Sometimes we have some configuration data that we need in our code, that can be changed periodically, like mail server information, proxy server, etc. We can...
Adding Swagger to Kotlin Spring
Spring makes it extremely easy to create REST api, but as a consumer of APIs, we need documentations to know what is available and how to use it. That’s wher...
How to create generic JPA repository
Generics makes it possible to reuse code, which is great. But when it needs to apply on a JPA repository, it can get messy. As any small mistake is going to ...
Issue with Jackson serialization of isGetter with continuous capital letters
Noticed a small issue while using jackson to serialize a data class with a property that is a “is-getter” and has continuous capital letters after the “is”. ...
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
No tests found when running Cucumber JUnit
Sometimes it can be pretty frustrating when the error message doesn’t show the root cause of the problem, usually that’s because it is not straightforward wh...
Material-UI
Bootstrap a NextJS Site with Material UI Blog Template
I was just trying out to bootstrap a website with NextJS and I wanted to apply the Blog template from Material UI Getting Started Templates but it wasn’t as ...
How to apply Material theme colors for your Angular Component
TLDR; Create a @mixin to receive the $theme as a parameter, so that you can get the colors you need from the $theme and apply it to your css selectors. The...
Defining your own theme in Angular Material
Having your own theme in your web application is essential to make it look professional. Imagine using the default color themes provided from the framework y...
Create a new NextJS site with Typescript, Material-UI, and Cypress
NextJS is a React framework that is great for static site generation, as it has the structure to pre-render the pages, provide routing, and bundling with web...
Cypress
Upgrade Angular project from v11 to v13
I’m slow…. It’s been a while since I last touched my Angular repository, that was created in early 2020, running on Angular 11. When I just went back to it y...
How to deploy NextJS with Cypress to AWS Amplify
I thought it should be pretty straightforward, since the AWS amplify documentation mentions it supports NextJS out of the box. However, when I try to deploy ...
How to inject certificate in cypress plugin to do e2e testing of https endpoint
Recently, I was involved to setup the e2e testing for the project at work. It’s usually a straightforward process to install cypress and get the test cases w...
Create a new NextJS site with Typescript, Material-UI, and Cypress
NextJS is a React framework that is great for static site generation, as it has the structure to pre-render the pages, provide routing, and bundling with web...
Gradle
Why I choose gradle over maven
Ever since coming across gradle as the build tool for java while working in Zuhlke, I have never looked back to using Maven. The immediate difference is obvi...
Getting started Spring Boot Application
Frameworks have made developing backend applications much easier compared to doing everything manually. For example, we no longer need to deal with the http ...
Mutation testing with Pitest
Beyond just ensuring every line of code is executed with Code Coverage test, there is another way to ensure the test cases written are adequate, and that is ...
Using Lombok in Intelli J
Lombok is a pretty neat tool when coding in Java, allowing me to save time writing repetitive codes. But when you are installing it in a new project or in a ...
Spring Testing
How to do integration testing in Spring Boot Rest application
Unlike unit tests where we should be isolating the test to just the codes in the function we are testing, integration tests is meant to test the full spectru...
How to unit test rest controller in a Spring boot application
Spring provides the @WebMvcTest annotation for testing Spring MVC components, providing only the configuration relevant to the MVC tests and not the full aut...
How to test services in a Spring boot application
Unit testing services is easy, cause we don’t need to set up any application context in Spring, since the purpose of unit testing is just to isolate testing ...
How to test Spring Data repository
Usually we do not need to write tests for the functionalities provided by the framework, but we can do so when certain functionalities we use from the framew...
Spring Security
How to create a user in Spring after login with OpenID Connect
Following my last article on creating OpenID Connect login with Spring Boot, we shall now enhance the application to create a user in our MongoDB database fo...
OpenID Connect login with Spring Boot
OpenID Connect (OIDC) is an identity authentication protocol, using the mechanism of OAuth2, to allow applications to delegate their login function to identi...
How to configure username password authentication in Spring Security
Continuing my previous article configuring CSRF with Spring Security, this time we are going to configure the authentication. Spring security provides all th...
Configure Spring Security CSRF for testing on Swagger
Today we are going to work on adding Spring Security to our Spring boot application. To start, we will first need to add the dependencies for Spring Securit...
Code Coverage
How to exempt lombok generated code from Jacoco
Lombok makes life easier for java developers by generating the mundane code (e.g. getters and setters) automatically, but if you are running code coverage, y...
Code coverage for Java - Jacoco
Testing is a very important process in software engineering to ensure the quality of the code we write, and we can ensure testing is adequate by doing code c...
Code coverage in Angular
Unit testing has been the quintessential way to ensure whatever code we add to our program doesn’t break anything, but how do we tell if the unit tests are a...
NextJS
Bootstrap a NextJS Site with Material UI Blog Template
I was just trying out to bootstrap a website with NextJS and I wanted to apply the Blog template from Material UI Getting Started Templates but it wasn’t as ...
How to deploy NextJS with Cypress to AWS Amplify
I thought it should be pretty straightforward, since the AWS amplify documentation mentions it supports NextJS out of the box. However, when I try to deploy ...
Create a new NextJS site with Typescript, Material-UI, and Cypress
NextJS is a React framework that is great for static site generation, as it has the structure to pre-render the pages, provide routing, and bundling with web...
interview questions
Java HashMap Explained
The implementation details of the java hashmap is a very common interview question for java developers, though I’m strongly against asking such question fo...
Algrebra, XOR, and its applications
Recently, I chanced upon this neat solution to a rather simple interview question, that exploits the special property of the binary XOR operation. It leads m...
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
NgRx
How to use router-store in NgRx
What is the purpose of the router-store in NgRx? As explained in my previous article on NgRx, the purpose of NgRx is to separate the data management part ...
How to test NgRx
Ngrx is a framework for angular that helps to separate the backend logic from the frontend, making the code easier cleaner. To know more about how it works...
NgRx Explained
Often times, when our angular applications grows, our code become quite messy to follow. We have multiple components, referencing a myriad number of servic...
Windows
Resolve git SSL certificate problem on windows
While trying to push my project to Azure DevOps on my corporate windows machine, I got this error message when I am trying to push my code - SSL certificate ...
Git detect dubious ownership in repository
When working in the corporate environment, we usually have a designated user space for each authenticated user on our computer. For example, in Windows, if...
Fix for filename too long in Git for Windows
If you are running git on windows, with a deeply nested folder structure in your code, you might get the error message - “Filename too long”. That is because...
GraphQL
How to handle internal error in Spring for GraphQL
This is an extension to the articles - Getting started with Spring and GraphQl and Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester....
Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester
Following my previous article on getting started with spring and graphql, let’s look at how we can do integration testing on the graphql spring boot applicat...
Getting started with Spring and GraphQl
The most common way of creating APIs is using REST (Representational State Transfer), of which we make use of the http verbs (POST, GET, PUT, DELETE) to stat...
Javascript
Java HashMap Explained
The implementation details of the java hashmap is a very common interview question for java developers, though I’m strongly against asking such question fo...
Code coverage in Angular
Unit testing has been the quintessential way to ensure whatever code we add to our program doesn’t break anything, but how do we tell if the unit tests are a...
git
How to remove accidental commits in git
This happens when I forgot to create the .gitignore file, resulting in the target folder containing the class files got uploaded to git. Solution git rm -r...
The fatal refusing to merge unrelated history
It occurs to me a few times when I have written my code, then I want to create a git repository to store it. Then I selected the option to create a README fi...
Maven
Why I choose gradle over maven
Ever since coming across gradle as the build tool for java while working in Zuhlke, I have never looked back to using Maven. The immediate difference is obvi...
Adding a catalog of Maven Archetypes in Intelli J
Archetypes make it easy to scaffold a project, but remembering all the archetypes available and using the command line to activate it can be challenging to r...
IntelliJ
Using Lombok in Intelli J
Lombok is a pretty neat tool when coding in Java, allowing me to save time writing repetitive codes. But when you are installing it in a new project or in a ...
Adding a catalog of Maven Archetypes in Intelli J
Archetypes make it easy to scaffold a project, but remembering all the archetypes available and using the command line to activate it can be challenging to r...
React
A Quick Start Refresher to React for Programmers
Like Angular, React is another popular library to build frontend single-page-applications. We can create a react app by using Create React App, run npx creat...
Create a new NextJS site with Typescript, Material-UI, and Cypress
NextJS is a React framework that is great for static site generation, as it has the structure to pre-render the pages, provide routing, and bundling with web...
documentation
Adding Swagger to Kotlin Spring
Spring makes it extremely easy to create REST api, but as a consumer of APIs, we need documentations to know what is available and how to use it. That’s wher...
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
Lombok
How to exempt lombok generated code from Jacoco
Lombok makes life easier for java developers by generating the mundane code (e.g. getters and setters) automatically, but if you are running code coverage, y...
Using Lombok in Intelli J
Lombok is a pretty neat tool when coding in Java, allowing me to save time writing repetitive codes. But when you are installing it in a new project or in a ...
Jacoco
How to exempt lombok generated code from Jacoco
Lombok makes life easier for java developers by generating the mundane code (e.g. getters and setters) automatically, but if you are running code coverage, y...
Code coverage for Java - Jacoco
Testing is a very important process in software engineering to ensure the quality of the code we write, and we can ensure testing is adequate by doing code c...
Cucumber
No tests found when running Cucumber JUnit
Sometimes it can be pretty frustrating when the error message doesn’t show the root cause of the problem, usually that’s because it is not straightforward wh...
Cucumber testing on Spring Boot
Cucumber is a great way for users to automate acceptance testing, as it allows using somewhat natural language to define the test cases. With a little learni...
Semantic Release
Using Semantic Release with Github Actions
The purpose of having Semantic-Release is so that we can release workable versions to our users frequently. So we shouldn’t be releasing non-workable version...
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
JPA
How to create generic JPA repository
Generics makes it possible to reuse code, which is great. But when it needs to apply on a JPA repository, it can get messy. As any small mistake is going to ...
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
Swagger
Configure Spring Security CSRF for testing on Swagger
Today we are going to work on adding Spring Security to our Spring boot application. To start, we will first need to add the dependencies for Spring Securit...
Adding Swagger to Kotlin Spring
Spring makes it extremely easy to create REST api, but as a consumer of APIs, we need documentations to know what is available and how to use it. That’s wher...
SpringDoc
Upgrade SpringDoc dependencies for Spring 3.0
In my previous article on how to add Swagger on Spring with Kotlin, the examples were built on Spring 2. With the introduction of Spring 3, there are some up...
Adding Swagger to Kotlin Spring
Spring makes it extremely easy to create REST api, but as a consumer of APIs, we need documentations to know what is available and how to use it. That’s wher...
MacOSX
Homebrew explained
What is Homebrew Homebrew is the missing package manager for macOS. What does that mean? In layman terms, it is like the Appstore, but for opensource softwa...
Enable accented characters on Mac OSX
I used to be able to type accented characters on Mac OSX by long pressing the character I want to accent. But this functionality was somehow gone after an OS...
Homebrew
Installing MariaDB on MacOS with Homebrew
MariaDB is a community-driven fork of the then open sourced MySql which was acquired by Oracle, and it is created by the original developers of MySql, and is...
Homebrew explained
What is Homebrew Homebrew is the missing package manager for macOS. What does that mean? In layman terms, it is like the Appstore, but for opensource softwa...
Docker
Deploying multi-container application to Docker
In my last post - Getting started Spring Boot Application, I demonstrated how to create a sample forum application with Spring Boot using MariaDB as the data...
Containerizing with Docker explained
After you have created your application, it is always nice to have it containerized so that it can be readily used whenever you need it, without having to cl...
NodeJS
Getting started with NestJS
NestJS is a nodejs framework for building backend applications, that is secure and scaleable. Following the SOLID principle, and having a modular architectur...
Getting started with Angular
What is Angular? In my opinion, Angular is the platform and framework for building your own customized html tags. While html has a fixed set of tags (e.g. &...
RxJs
Observables Explained
We all know what is a function. It takes some or no inputs and produce just 1 output. function doSomething(input1, input2){ return input1 + input2; } Wh...
NgRx Explained
Often times, when our angular applications grows, our code become quite messy to follow. We have multiple components, referencing a myriad number of servic...
Stream
Creating and filling a 2D array using Functional Programming in Java
Java stream is a wonderful addition since Java 8 to create and manipulate arrays/lists with ease. However, as other new programming languages can do all the ...
Java Arrays Lists & Streams Reference
// Initialize Arrays Integer[] integerArray = {1, 2, 3, 4, 5}; System.out.println(Arrays.toString(integerArray)); // Initialize List List<Integer> int...
Theming
How to apply Material theme colors for your Angular Component
TLDR; Create a @mixin to receive the $theme as a parameter, so that you can get the colors you need from the $theme and apply it to your css selectors. The...
Defining your own theme in Angular Material
Having your own theme in your web application is essential to make it look professional. Imagine using the default color themes provided from the framework y...
Angular Material
How to apply Material theme colors for your Angular Component
TLDR; Create a @mixin to receive the $theme as a parameter, so that you can get the colors you need from the $theme and apply it to your css selectors. The...
Defining your own theme in Angular Material
Having your own theme in your web application is essential to make it look professional. Imagine using the default color themes provided from the framework y...
Frontend
A Quick Start Refresher to React for Programmers
Like Angular, React is another popular library to build frontend single-page-applications. We can create a react app by using Create React App, run npx creat...
How to pass data from angular to css
I am creating an angular template whereby I can create forms from a data file automatically, such as a json or yaml. For displaying on the monitor screen, ...
MariaDB
Installing MariaDB on MacOS with Homebrew
MariaDB is a community-driven fork of the then open sourced MySql which was acquired by Oracle, and it is created by the original developers of MySql, and is...
Deploying multi-container application to Docker
In my last post - Getting started Spring Boot Application, I demonstrated how to create a sample forum application with Spring Boot using MariaDB as the data...
Mockito
How to unit test rest controller in a Spring boot application
Spring provides the @WebMvcTest annotation for testing Spring MVC components, providing only the configuration relevant to the MVC tests and not the full aut...
How to test services in a Spring boot application
Unit testing services is easy, cause we don’t need to set up any application context in Spring, since the purpose of unit testing is just to isolate testing ...
Spring Web
How to create custom validation annotation
When we have an application that collects inputs from users, we usually need to have some validation checks to ensure user inputs are within what is expected...
How to validate input in Spring Boot RestController
Validating user inputs is not a difficult task, but it is rather cumbersome. Although essential, having lots of validation checks in the code makes the code ...
Validation
How to create custom validation annotation
When we have an application that collects inputs from users, we usually need to have some validation checks to ensure user inputs are within what is expected...
How to validate input in Spring Boot RestController
Validating user inputs is not a difficult task, but it is rather cumbersome. Although essential, having lots of validation checks in the code makes the code ...
Rebase
How to squash commits
Why do we need to squash commits Sometimes when we are working on a feature, we might forget to run all the tests before we commit, and we could get test fa...
How to fix a git rebase on a public master branch
What is Git Rebase The git rebase is a command in Git that allows you to modify the commit history of a branch by moving or combining a sequence of commits ...
OAuth2
How to create a user in Spring after login with OpenID Connect
Following my last article on creating OpenID Connect login with Spring Boot, we shall now enhance the application to create a user in our MongoDB database fo...
OpenID Connect login with Spring Boot
OpenID Connect (OIDC) is an identity authentication protocol, using the mechanism of OAuth2, to allow applications to delegate their login function to identi...
OpenID Connect
How to create a user in Spring after login with OpenID Connect
Following my last article on creating OpenID Connect login with Spring Boot, we shall now enhance the application to create a user in our MongoDB database fo...
OpenID Connect login with Spring Boot
OpenID Connect (OIDC) is an identity authentication protocol, using the mechanism of OAuth2, to allow applications to delegate their login function to identi...
MongoDB
Spring boot testing with MongoDB using TestContainers
When we need to test our spring boot application that is running MongoDB, it will by default connect to the MongoDB instance with the connection details in o...
How to create a user in Spring after login with OpenID Connect
Following my last article on creating OpenID Connect login with Spring Boot, we shall now enhance the application to create a user in our MongoDB database fo...
HttpGraphQlTester
How to handle internal error in Spring for GraphQL
This is an extension to the articles - Getting started with Spring and GraphQl and Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester....
Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester
Following my previous article on getting started with spring and graphql, let’s look at how we can do integration testing on the graphql spring boot applicat...
Spring Boot GraphQL Starter
How to handle internal error in Spring for GraphQL
This is an extension to the articles - Getting started with Spring and GraphQl and Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester....
Integration testing on Spring Boot GraphQL Starter with HttpGraphQlTester
Following my previous article on getting started with spring and graphql, let’s look at how we can do integration testing on the graphql spring boot applicat...
AWS
Creating a simple serverless application with AWS SAM on local
Amazon Web Services Serverless Application Model (AWS SAM) is a platform to help developers quick-start a lambda application with all the essentials and basi...
AWS SAM
Creating a simple serverless application with AWS SAM on local
Amazon Web Services Serverless Application Model (AWS SAM) is a platform to help developers quick-start a lambda application with all the essentials and basi...
AWS Lambda
Creating a simple serverless application with AWS SAM on local
Amazon Web Services Serverless Application Model (AWS SAM) is a platform to help developers quick-start a lambda application with all the essentials and basi...
Cloud Computing
Creating a simple serverless application with AWS SAM on local
Amazon Web Services Serverless Application Model (AWS SAM) is a platform to help developers quick-start a lambda application with all the essentials and basi...
Istanbul JS
Code coverage in Angular
Unit testing has been the quintessential way to ensure whatever code we add to our program doesn’t break anything, but how do we tell if the unit tests are a...
NPM
How to publish Angular component to NPM
There are some requirements that a module needs to fullfil before it can be published to npm. For example, you’ll need a main field in your package.json http...
Http Server
Simple http server to test Angular production build
After creating the production build for an Angular project with ng build --prod, the output is a folder of html and javascript, which will only work if you s...
Typescript
Create a new NextJS site with Typescript, Material-UI, and Cypress
NextJS is a React framework that is great for static site generation, as it has the structure to pre-render the pages, provide routing, and bundling with web...
PMP
The updated 5-PG, 10-KA, 49-Processes for PMBOK v6
I’ve got my certification in PMP back in 2017, when the PMBOK is at the 5th edition. So recently I had a quick review of the new 6th edition, and here are my...
PMI
The updated 5-PG, 10-KA, 49-Processes for PMBOK v6
I’ve got my certification in PMP back in 2017, when the PMBOK is at the 5th edition. So recently I had a quick review of the new 6th edition, and here are my...
e2e testing
How to inject certificate in cypress plugin to do e2e testing of https endpoint
Recently, I was involved to setup the e2e testing for the project at work. It’s usually a straightforward process to install cypress and get the test cases w...
Good Code
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
automated testing
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
clean code
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
code review
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
pair programming
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
time management
My ingredient list for good code
My ingredient list for good code Ample documentation Automated testing with good coverage Clean, legible and side-effect free Second opinion (code ...
Harvard Business Review
Excerpt from HBR - How Consultants Project Expertise and Learn at the Same Time
My take from the article - https://hbr.org/2018/07/how-consultants-project-expertise-and-learn-at-the-same-time Consultants might not always have the in-dep...
Consultant
Excerpt from HBR - How Consultants Project Expertise and Learn at the Same Time
My take from the article - https://hbr.org/2018/07/how-consultants-project-expertise-and-learn-at-the-same-time Consultants might not always have the in-dep...
AWS Amplify
How to deploy NextJS with Cypress to AWS Amplify
I thought it should be pretty straightforward, since the AWS amplify documentation mentions it supports NextJS out of the box. However, when I try to deploy ...
Machine Learning
Machine Learning in a nutshell
A simple explanation of the use of machine learning, is the prediction of result based on past data. In order to do that, you’ll need a lot of data, because ...
Github
Updating the remote to incorporate the new personal access token requirement on github
Recently github has discontinued the using of username and password - https://github.blog/2020-12-15-token-authentication-requirements-for-git-operations/. S...
Mutation Testing
Mutation testing with Pitest
Beyond just ensuring every line of code is executed with Code Coverage test, there is another way to ensure the test cases written are adequate, and that is ...
Pitest
Mutation testing with Pitest
Beyond just ensuring every line of code is executed with Code Coverage test, there is another way to ensure the test cases written are adequate, and that is ...
BDD
Cucumber testing on Spring Boot
Cucumber is a great way for users to automate acceptance testing, as it allows using somewhat natural language to define the test cases. With a little learni...
Semantic Versioning
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
GitHub Actions
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
Continuous Integration
Basic guide to Semantic Release
When it comes to releasing software projects to production, versioning can be a topic that is easily overlooked as something that is too trivial and done man...
JUnit
No tests found when running Cucumber JUnit
Sometimes it can be pretty frustrating when the error message doesn’t show the root cause of the problem, usually that’s because it is not straightforward wh...
ImportanceOfDocumentation
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
ImportanceOfGoodNaming
Difference between getById and findById in Spring JPA
Use getById() if you just want to get a reference of the entity, like assigning it to a property of another entity. Use findById() if you actually want to g...
SOLID
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Single Responsibility
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Open-Closed
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Liskov Substitution
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Interface Segregation
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Dependency Inversion
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Object-oriented Design
The SOLID Principle in internet lingo
The SOLID principle is one of the most common acronym to describe the principles of object-oriented programming, which is subset of the many principles intro...
Dependency Injection
Dependency Injection
Dependency Injection is like a job matching service for variables in your code. You specify the job description, in the form of interface, or in a less ideal...
Jackson
Issue with Jackson serialization of isGetter with continuous capital letters
Noticed a small issue while using jackson to serialize a data class with a property that is a “is-getter” and has continuous capital letters after the “is”. ...
Json
Issue with Jackson serialization of isGetter with continuous capital letters
Noticed a small issue while using jackson to serialize a data class with a property that is a “is-getter” and has continuous capital letters after the “is”. ...
Generics
How to create generic JPA repository
Generics makes it possible to reuse code, which is great. But when it needs to apply on a JPA repository, it can get messy. As any small mistake is going to ...
Protractor
Upgrade Angular project from v11 to v13
I’m slow…. It’s been a while since I last touched my Angular repository, that was created in early 2020, running on Angular 11. When I just went back to it y...
Tslint
Upgrade Angular project from v11 to v13
I’m slow…. It’s been a while since I last touched my Angular repository, that was created in early 2020, running on Angular 11. When I just went back to it y...
Eslint
Upgrade Angular project from v11 to v13
I’m slow…. It’s been a while since I last touched my Angular repository, that was created in early 2020, running on Angular 11. When I just went back to it y...
External Configuration
How to get external configuration in Spring
Sometimes we have some configuration data that we need in our code, that can be changed periodically, like mail server information, proxy server, etc. We can...
Cakebrew
Homebrew explained
What is Homebrew Homebrew is the missing package manager for macOS. What does that mean? In layman terms, it is like the Appstore, but for opensource softwa...
Algebra
Algrebra, XOR, and its applications
Recently, I chanced upon this neat solution to a rather simple interview question, that exploits the special property of the binary XOR operation. It leads m...
XOR
Algrebra, XOR, and its applications
Recently, I chanced upon this neat solution to a rather simple interview question, that exploits the special property of the binary XOR operation. It leads m...
binary operations
Algrebra, XOR, and its applications
Recently, I chanced upon this neat solution to a rather simple interview question, that exploits the special property of the binary XOR operation. It leads m...
Containerization
Containerizing with Docker explained
After you have created your application, it is always nice to have it containerized so that it can be readily used whenever you need it, without having to cl...
Frontend Development
Getting started with Angular
What is Angular? In my opinion, Angular is the platform and framework for building your own customized html tags. While html has a fixed set of tags (e.g. &...
Hiring
5 Reasons why Online Coding Assessments are pointless
1. It doesn’t reflect the real world programming experience This can’t be more straightforward. When is the last time anyone need to solve a secondary schoo...
Technical Assessment
5 Reasons why Online Coding Assessments are pointless
1. It doesn’t reflect the real world programming experience This can’t be more straightforward. When is the last time anyone need to solve a secondary schoo...
Coding Assessment
5 Reasons why Online Coding Assessments are pointless
1. It doesn’t reflect the real world programming experience This can’t be more straightforward. When is the last time anyone need to solve a secondary schoo...
Github Actions
Using Semantic Release with Github Actions
The purpose of having Semantic-Release is so that we can release workable versions to our users frequently. So we shouldn’t be releasing non-workable version...
Jekyll
Escaping the {{ }} in markdown for Jekyll
I just realised that in one of my previous posts, the code I had for ${{ secrets.GH_TOKEN }} became just $. After a bit of research, I found out that it is ...
Markdown
Escaping the {{ }} in markdown for Jekyll
I just realised that in one of my previous posts, the code I had for ${{ secrets.GH_TOKEN }} became just $. After a bit of research, I found out that it is ...
Liquid Templating Language
Escaping the {{ }} in markdown for Jekyll
I just realised that in one of my previous posts, the code I had for ${{ secrets.GH_TOKEN }} became just $. After a bit of research, I found out that it is ...
Router
How to do navigation in Angular
When you create a new angular app using ng new <application name>, the first question you get asked is ? Would you like to add Angular routing? (y/N). ...
Environment Variable
How to use environment variable in Angular
Angular automatically creates 2 files - environment.ts and environment.prod.ts, in the environment folder when the project is first created. Both of them has...
HttpClientModule
How to test HttpClient in Angular
This is a simple method to call http using the HttpClientModule. getBooks(): Observable<Book[]>{ return this.http.get<Book[]>(BooksService.b...
HttpClientTestingModule
How to test HttpClient in Angular
This is a simple method to call http using the HttpClientModule. getBooks(): Observable<Book[]>{ return this.http.get<Book[]>(BooksService.b...
Array
Java Arrays Lists & Streams Reference
// Initialize Arrays Integer[] integerArray = {1, 2, 3, 4, 5}; System.out.println(Arrays.toString(integerArray)); // Initialize List List<Integer> int...
List
Java Arrays Lists & Streams Reference
// Initialize Arrays Integer[] integerArray = {1, 2, 3, 4, 5}; System.out.println(Arrays.toString(integerArray)); // Initialize List List<Integer> int...
Effects
How to test NgRx
Ngrx is a framework for angular that helps to separate the backend logic from the frontend, making the code easier cleaner. To know more about how it works...
Functional Programming
Creating and filling a 2D array using Functional Programming in Java
Java stream is a wonderful addition since Java 8 to create and manipulate arrays/lists with ease. However, as other new programming languages can do all the ...
Rubik's Cube
Simulating Rubik Cube Actions with Java
Let’s work on something fun today, simulating a rubik’s cube. This is the precursor to my next topic to provide the solution to solve rubik’s cube. Modell...
Router-Store
How to use router-store in NgRx
What is the purpose of the router-store in NgRx? As explained in my previous article on NgRx, the purpose of NgRx is to separate the data management part ...
HashMap
Java HashMap Explained
The implementation details of the java hashmap is a very common interview question for java developers, though I’m strongly against asking such question fo...
Observable
Observables Explained
We all know what is a function. It takes some or no inputs and produce just 1 output. function doSomething(input1, input2){ return input1 + input2; } Wh...
Observer Pattern
Observables Explained
We all know what is a function. It takes some or no inputs and produce just 1 output. function doSomething(input1, input2){ return input1 + input2; } Wh...
CSS
How to pass data from angular to css
I am creating an angular template whereby I can create forms from a data file automatically, such as a json or yaml. For displaying on the monitor screen, ...
MatSelect
Testing MatOptionHarness in MatSelectHarness
Reminder to self: When trying to get the options in the MatSelectHarness in Angular Material, you need to simulate a click on the MatSelectHarness - await se...
MatOption
Testing MatOptionHarness in MatSelectHarness
Reminder to self: When trying to get the options in the MatSelectHarness in Angular Material, you need to simulate a click on the MatSelectHarness - await se...
Material Angular
Testing MatOptionHarness in MatSelectHarness
Reminder to self: When trying to get the options in the MatSelectHarness in Angular Material, you need to simulate a click on the MatSelectHarness - await se...
SID
Git detect dubious ownership in repository
When working in the corporate environment, we usually have a designated user space for each authenticated user on our computer. For example, in Windows, if...
Security
Git detect dubious ownership in repository
When working in the corporate environment, we usually have a designated user space for each authenticated user on our computer. For example, in Windows, if...
Spring 3.0
Upgrade SpringDoc dependencies for Spring 3.0
In my previous article on how to add Swagger on Spring with Kotlin, the examples were built on Spring 2. With the introduction of Spring 3, there are some up...
Docker Compose
Deploying multi-container application to Docker
In my last post - Getting started Spring Boot Application, I demonstrated how to create a sample forum application with Spring Boot using MariaDB as the data...
Multi Stage Build
Deploying multi-container application to Docker
In my last post - Getting started Spring Boot Application, I demonstrated how to create a sample forum application with Spring Boot using MariaDB as the data...
Spring Data
How to test Spring Data repository
Usually we do not need to write tests for the functionalities provided by the framework, but we can do so when certain functionalities we use from the framew...
Integration Testing
How to do integration testing in Spring Boot Rest application
Unlike unit tests where we should be isolating the test to just the codes in the function we are testing, integration tests is meant to test the full spectru...
Code review
Integrate code quality review with SonarQube
In today’s environment, when we are having tons of dependencies in our application project, as developers we need to take care not just of the business logic...
SonarQube
Integrate code quality review with SonarQube
In today’s environment, when we are having tons of dependencies in our application project, as developers we need to take care not just of the business logic...
BA
Integrate code quality review with SonarQube
In today’s environment, when we are having tons of dependencies in our application project, as developers we need to take care not just of the business logic...
CSRF
Configure Spring Security CSRF for testing on Swagger
Today we are going to work on adding Spring Security to our Spring boot application. To start, we will first need to add the dependencies for Spring Securit...
Authentication
How to configure username password authentication in Spring Security
Continuing my previous article configuring CSRF with Spring Security, this time we are going to configure the authentication. Spring security provides all th...
Squash
How to squash commits
Why do we need to squash commits Sometimes when we are working on a feature, we might forget to run all the tests before we commit, and we could get test fa...
Sequel Pro
Installing MariaDB on MacOS with Homebrew
MariaDB is a community-driven fork of the then open sourced MySql which was acquired by Oracle, and it is created by the original developers of MySql, and is...
Heidi SQL
Installing MariaDB on MacOS with Homebrew
MariaDB is a community-driven fork of the then open sourced MySql which was acquired by Oracle, and it is created by the original developers of MySql, and is...
Database
Installing MariaDB on MacOS with Homebrew
MariaDB is a community-driven fork of the then open sourced MySql which was acquired by Oracle, and it is created by the original developers of MySql, and is...
TestContainers
Spring boot testing with MongoDB using TestContainers
When we need to test our spring boot application that is running MongoDB, it will by default connect to the MongoDB instance with the connection details in o...
NoSQL
Spring boot testing with MongoDB using TestContainers
When we need to test our spring boot application that is running MongoDB, it will by default connect to the MongoDB instance with the connection details in o...
NestJS
Getting started with NestJS
NestJS is a nodejs framework for building backend applications, that is secure and scaleable. Following the SOLID principle, and having a modular architectur...
Spring Cloud
Quick start tutorial on MicroServices with Spring Cloud Netflix Eureka
In traditional application development, we have everything under a single project. But when the project gets bigger, involving multiple teams, it might make ...
Netflix Eureka
Quick start tutorial on MicroServices with Spring Cloud Netflix Eureka
In traditional application development, we have everything under a single project. But when the project gets bigger, involving multiple teams, it might make ...
Microservices
Quick start tutorial on MicroServices with Spring Cloud Netflix Eureka
In traditional application development, we have everything under a single project. But when the project gets bigger, involving multiple teams, it might make ...
OpenFeign
Quick start tutorial on MicroServices with Spring Cloud Netflix Eureka
In traditional application development, we have everything under a single project. But when the project gets bigger, involving multiple teams, it might make ...