deno.tar.gz

Deno

Deno is a simple and secure runtime for JavaScript and TypeScript and it’s on the rise. It has many similarities to Node, but it also has some useful new features such as: security by default, TypeScript by default, ES modules, and improved package management.

If you want to be on the cutting edge of the latest web development technologies then Deno is a good start.

In this mini course, you will first refresh your understanding of TypeScript, as it is extensively used with Deno. You will cover the basic types as well as interfaces and classes.

In the second half of this course, you will learn how to create a CRUD REST API using Deno and Oak. By the end of this course, you can add a great new skill to your resume and you can start experimenting with it in old or new projects.

Creating a CRUD REST API with Deno & Oak

# Update a book
Now that we've learned how to get books and even add one, it's time we learned how to update an existing book in our REST API. Spoiler alert: This will be a combination of `getBook` and `addBook`. Why do we need such a functionality? Maybe we made a typo somewhere or stored the wrong data. 

export interface IBook {
    id: string;
    name: string;
    author: string;
    genre: string;   
}

import { Application } from "https://deno.land/x/oak/mod.ts";
import router from './routes/routes.ts';

const port = 8000;

const app = new Application();

app.use(router.routes());
app.use(router.allowedMethods());

console.log(`server running at ${port}`)
await app.listen({ port });

import React from 'react';
import { shallow, configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

import HelloWorld from './app';

var TestResult = function() {
    this.succeeded = false;
    this.reason = "";
    this.input = "";
    this.expected_output = "";
    this.actual_output = "";
}

export const executeTests = function() {

  var results = [];

  result = new TestResult();
  result.input = 'HelloWorld Component';
  result.expected_output = "span containing text 'Hello World'"

  let wrapper = shallow(<HelloWorld />);

  // Call your Challenge function here.

  let type = wrapper.type();
  let testSuccessful = true;
  let failureReason;

  if (type !== 'span') {
    testSuccessful = false;
    failureReason = "You need to render exactly one span HTML element";
  } else if (wrapper.props().children != "Hello World") {
     testSuccessful = false;
     failureReason = "You have rendered wrong message in your span element";
  }

  result.actual_output = wrapper.html();

  if (testSuccessful) {
    result.succeeded = true;
    result.reason = "Succeeded"
  } else {
    result.succeeded = false;
    result.reason = failureReason;
  }

  results.push(result);

  return results;
}


React

Dart

GoJS React

Typescript React

Vue.js

- Let's have a look at the `updateBook` method in `books.ts` in `line 89`. As stated earlier, we will be using a combination of `getBook` and `addBook` here. We'll take three things as arguments: `params`, `request` and `response`. 
- We'll use `params` to get the id of the book and `request` to get the data with which the book needs to be updated. As in `getBook`, we first need to check if the book with that id exists on `line 90`. 
- If it does, we need to take in the value of `request.body`. We need to destructure the value. and store it in an `updatedData` variable. Notice that when we destructure, we put a question mark in front of semicolons i.e., the semicolons are optional. This is because the `request` body may contain any combination of those attributes. A user might want to update just one attribute of a certain book or all the properties of a certain book.

- We then map through the `books` array and use the spread operator to update the book whose id matches with `params.id`. Once that's done, we send the array back as a response, with a status code of 200. The else statement remains the same.

- We declare a `PUT` route for this in `routes.ts` on `line 9`.

Once you run the above code, try to send a `PUT` request to the URL appended with `/api/v1/books/1` and the following body.
```
{ "genre": "novel" }
```
You should see the following response.

In this lesson, we'll add the last two routes left in our CRUD REST API.

__default

Adding New Routes Part II

Update a book