Node.js Mocha and Chai

Mocha is a test framework to run tests.

https://mochajs.org/#assertions

Chai is an assertion library and you can find full documentation in the following link.

https://www.chaijs.com/api/bdd/

There are three type of assertion libraries in Chai.

  • Expect
  • Should
  • Assert

expect and should use the same chainable language to construct assertions.

Assume that expect library is used like below

expect(firstName).to.be.a('string');
expect(firstName).to.equal('kenan');
expect(firstName).to.have.lengthOf(5);
expect(beverages).to.have.property('tea').with.lengthOf(3);

Above code could be written with should library like below.

firstName.should.be.a('string');
firstName.should.equal('kenan');
firstName.should.have.lengthOf(5);
beverages.should.have.property('tea').with.lengthOf(3);

You can find more detailed usage with Express, Mocha and Chai in the following repository

https://github.com/nodejs-projects-kenanhancer/express-demo.git

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Node.js Axios Usage

Node.js Babel 7.x different usage transpiling to ES5 and Debugging

I already mentioned many details in the following link. So I don't want to duplicate everything in this post one more time.

You can reach github project from the following link.

https://github.com/kenanhancer/babel7-usage.git

You can reach Babel 6.x post from the following link.

Creating Babel configuration file

.babelrc

{
  "presets": [
    "@babel/preset-env",
    "@babel/preset-react"
  ],
  "plugins": [
    "@babel/plugin-transform-runtime"
  ],
  "env": {
    "development": {
      "presets": [
        [
          "@babel/preset-react",
          {
            "development": true
          }
        ]
      ],
      "sourceMaps": true,
      "retainLines": true
    }
  }
}

Node.js nut-pipe usage

nut-pipe npm package is an implementation of Chain of Responsibility Pattern. We can encapsulate or wrap every aspect of code in separate module or class or function, etc. So that, separated aspect modules would implement Single Responsibility Principle(SRP) and Seperation of Concern Principle(SoC) properly.

🙂 so if you want to implement OOP basics and principles, then you can use nut.pipe npm package.

This design provides to developer clean business logic code. They don't need to think about Error, Exception, Log handling business logic. Before their business logic code is called, pipeline is called and it means first middleware is triggered then first middleware will trigger next one, but no middleware knows about next middleware. Middleware should know about its business logic then should call next one.

I know too much words but developers want to see code 🙂 same code will be developed in different ways.

Code example v1

I wrote a greeting service with sayHello() and sayGoodbye() functions. They include all business logic in their body. This is not good approach definitely. Code duplications are everywhere 🙂 For example, every functions have try/catch, console.log('ENTRY: …'), console.log('SUCCESS: …'), console.log('ERROR: …'), etc. Notice that getFullName doesn't contain these business logics. So, we can't know whether it is called or not. If developer like me 🙂 doesn't write these kind of aspects(logging and exception handling is kind of aspect) then we never understand that that method is called in run-time.

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LoopBack 3 – Simple API with Oracle Example

Expose your Oracle Database as a REST service with LoopBack 3 (Node.js Open API Framework)

This post is continuation of previous post. So if you want to start from beginning, read that one as well.

Follow this link to create a Oracle container 🙂

You can find LoopBack 3 project in the following repository. After clonning switch to oracle branch 🙂 or run the following command.

git checkout oracle

https://github.com/kenanhancer/loopback3-simple-api.git

LoopBack 3 – Simple API with Redis Example

Expose your Redis NoSQL as a REST service with LoopBack 3 (Node.js Open API Framework)

This post is continuation of previous post. So if you want to start from beginning, read that one as well.

You can find LoopBack 3 project in the following repository. After clonning switch to mongodb branch 🙂 or run the following command.

git checkout redis

https://github.com/kenanhancer/loopback3-simple-api.git

LoopBack 3 – Simple API with MongoDB Example

Expose your MongoDB NoSQL as a REST service with LoopBack 3 (Node.js Open API Framework)

This post is continuation of previous post. So if you want to start from beginning, read that one as well.

Follow this link to create a MongoDB Docker container 🙂

You can find LoopBack 3 project in the following repository. After clonning switch to mongodb branch 🙂 or run the following command.

git checkout mongodb

https://github.com/kenanhancer/loopback3-simple-api.git