Tributes

Big thanks to @polcham for providing such a good template https://github.com/polcham/mongoose-express-ts

Prerequisites

To build and run this app locally you will need a few things:

Install Node.js
Install VS Code – Install Docker

Getting started

Clone the repository

– Fill the .env file: Note: example is at ./.env.example

– Spin up the environment

kubectl create -f nodejs-service.yaml,nodejs-deployment.yaml,nodejs-env-configmap.yaml,db-service.yaml,db-deployment.yaml,dbdata-persistentvolumeclaim.yaml,secret.yaml

Use minikube to start it

Finally, navigate to http://your_pod_ip_address:5000/ and you should see the API running!

Also, if you want to publish those on GKE with a custom namespace, use this command kubectl apply --validate=true -f nodejs-service.yaml,nodejs-deployment.yaml,nodejs-env-configmap.yaml,db-service.yaml,db-deployment.yaml,dbdata-persistentvolumeclaim.yaml,secret.yaml --namespace=dev

Project Structure

The most obvious difference in a TypeScript + Node project is the folder structure. In a TypeScript project, it's best to have separate source and distributable files. TypeScript (.ts) files live in your src folder and after compilation are output as JavaScript (.js) in the dist folder.

The full folder structure of this app is explained below:

Note! Make sure you have already built the app using npm run start

Name	Description
config	Contains config environment to be used by the config package, such as MongoDB URI, jwtSecret, and etc.
dist	Contains the distributable (or output) from your TypeScript build
node_modules	Contains all your npm dependencies
REST	Contains all API requests to test the routes, used with REST Client VSCode extension
src	Contains your source code that will be compiled to the dist dir
src/middleware	Contains the middlewares to intercept requests
src/models	Models define Mongoose schemas that will be used in storing and retrieving data from MongoDB
src/routes	Routes define the endpoints of your API
src/types	Contains all your custom types to better handle type checking with TypeScript
src/server.ts	Entry point to your express app
package.json	File that contains npm dependencies as well as build scripts
tsconfig.json	Config settings for compiling server code written in TypeScript
tslint.json	Config settings for TSLint code style checking

Configuring TypeScript compilation

TypeScript uses the file tsconfig.json to adjust project compile options. Let's dissect this project's tsconfig.json, starting with the compilerOptions which details how your project is compiled.

    "compilerOptions": {
    "module": "commonjs",
    "esModuleInterop": true,
    "target": "es6",
    "noImplicitAny": true,
    "moduleResolution": "node",
    "sourceMap": true,
    "outDir": "dist",
    "baseUrl": ".",
    "paths": {
      "*": ["node_modules/*", "src/types/*"]
    }
  }

`compilerOptions`	Description
`"module": "commonjs"`	The output module type (in your `.js` files). Node uses commonjs, so that is what we use
`"esModuleInterop": true,`	Allows usage of an alternate module import syntax: `import foo from 'foo';`
`"target": "es6"`	The output language level. Node supports ES6, so we can target that here
`"noImplicitAny": true`	Enables a stricter setting which throws errors when something has a default `any` value
`"moduleResolution": "node"`	TypeScript attempts to mimic Node's module resolution strategy. Read more here
`"sourceMap": true`	We want source maps to be output along side our JavaScript. See the debugging section
`"outDir": "dist"`	Location to output `.js` files after compilation
`"baseUrl": "."`	Part of configuring module resolution. See path mapping section
`paths: {...}`	Part of configuring module resolution. See path mapping section

The rest of the file define the TypeScript project context. The project context is basically a set of options that determine which files are compiled when the compiler is invoked with a specific tsconfig.json. In this case, we use the following to define our project context:

    "include": [
        "src/**/*"
    ]

include takes an array of glob patterns of files to include in the compilation. This project is fairly simple and all of our .ts files are under the src folder.

Running the build

All the different build steps are orchestrated via npm scripts. Npm scripts basically allow us to call (and chain) terminal commands via npm. This is nice because most JavaScript tools have easy to use command line utilities allowing us to not need grunt or gulp to manage our builds. If you open package.json, you will see a scripts section with all the different scripts you can call. To call a script, simply run npm run <script-name> from the command line. You'll notice that npm scripts can call each other which makes it easy to compose complex builds out of simple individual build scripts. Below is a list of all the scripts this template has available:

Npm Script	Description
`tsc`	Transpiles TypeScript codes to JavaScript.
`watch-tsc`	Transpiles TypeScript codes to JavaScript, with auto reload.
`deploy`	Runs node on `dist/server.js` which is the app's entry point.
`watch-deploy`	Runs node on `dist/server.js` which is the app's entry point, with auto reload.
`server`	Transpiles TypeScript codes to JavaScript then run node on `dist/server.js` with auto reload.
`start`	Transpiles TypeScript codes to JavaScript then run node on `dist/server.js`.