README
TypeScript Node Starter
Live Demo: https://typescript-node-starter.azurewebsites.net/
The main purpose of this repository is to show a good end-to-end project setup and workflow for writing Node code in TypeScript. I will try to keep this as up-to-date as possible, but community contributions and recommendations for improvements are encouraged and will be most welcome.
Pre-reqs
To build and run this app locally you will need a few things:
Getting started
- Clone the repository
git clone --depth=1 https://github.com/Microsoft/TypeScript-Node-Starter.git <project_name>
- Install dependencies
cd <project_name>
npm install
- Configure your mongoDB server
# create the db directory
sudo mkdir -p /data/db
# give the db correct read/write permissions
sudo chmod 777 /data/db
- Start your mongoDB server (you'll probably want another command prompt)
mongod
- Build and run the project
npm run build
npm start
Or, if you're using VS Code, you can use cmd + shift + b
to run the default build task (which is mapped to npm run build
), and then you can use the command palette (cmd + shift + p
) and select Tasks: Run Task
> npm: start
to run npm start
for you.
Note on editors! - TypeScript has great support in every editor, but this project has been pre-configured for use with VS Code. Throughout the README I'll try to call out specific places where VS Code really shines or where this project has been setup to take advantage of specific features.
Finally, navigate to http://localhost:3000
and you should see the template being served and rendered locally!
Deploying the app
There are many ways to deploy an Node app, and in general, nothing about the deployment process changes because you're using TypeScript. In this section, I'll walk you through how to deploy this app to Azure App Service using the extensions available in VS Code because I think it is the easiest and fastest way to get started, as well as the most friendly workflow from a developer's perspective.
Pre-reqs
- Azure account - If you don't have one, you can sign up for free. The Azure free tier gives you plenty of resources to play around with including up to 10 App Service instances, which is what we will be using.
- VS Code - We'll be using the interface provided by VS Code to quickly deploy our app.
- Azure App Service VS Code extension - In VS Code, search for
Azure App Service
in the extension marketplace (5th button down on the far left menu bar), install the extension, and then reload VS Code. - Create a cloud database - For local development, running MongoDB on localhost is fine, however once we deploy we need a database with high availability. The easiest way to achieve this is by using a managed cloud database. There are many different providers, but the easiest one to get started with is MongoLab.
Create a managed MongoDB with MongoLab
- Navigate to MongoLab's Website, sign up for a free account, and then log in.
- In the MongoDB Deployments section, click the Create New button.
- Select any provider (I recommend Microsoft Azure as it provides an easier path to upgrading to globally distributed instances later).
- Select Sandbox to keep it free unless you know what you're doing, and hit Continue.
- Select a region (I recommend the region geographically closest to your app's users).
- Add a name, click Continue again, and finally Submit Order.
- Once your new database is created, select it from the MongoDB Deployments section.
- Create a user by selecting the User tab, clicking the Add database user button, adding a username and password, and then clicking Create. A user account is required to connect to the database, so remember these values because you will need them as part of your connection string.
- Copy the connection string from the top of the page, it should look like this:
mongodb://<dbuser>:<dbpassword>@ds036069.mlab.com:36069/test-asdf
and replace<dbUser>
and<dbpassword>
with the credentials you just created. Back in your project, open your.env
file and updateMONGODB_URI
with your new connection string.NOTE! - If you don't have an
.env
file yet, rename.env.example
to.env
and follow the comments to update the values in that file. - Success!
You can test that it works locally by updating
MONGODB_URI_LOCAL
to the same connection string you just updated inMONGO_URI
. After rebuilding/serving, the app should work, but users that were previously created in local testing will not exist in the new database! Don't forget to return theMONGO_URI_LOCAL
to your local test database (if you so desire).
Deploying to Azure App Service
Deploying from VS Code can be broken into the following steps:
- Authenticate your Azure account in VS Code
- Build your app
- Zip deploy using the Azure App Service extension
Sign in to your Azure account
- Open VS Code
- Expand the Azure App Service menu in the explorer menu
- If you don't see this, you might not have the
Azure App Service
extension installed. See the pre-reqs section.
- If you don't see this, you might not have the
- Click
Sign in to Azure...
- Choose
Copy & Open
from the resulting dialog- This will open
aka.ms/devicelogin
in a browser window. If it doesn't, just navigate there manually.
- This will open
- Paste in the code that is on your clipboard.
- Go back to VS Code, you should now be signed in. You can confirm that everything worked by seeing your Azure subscription listed in the Azure App Service section of the explorer window. Additionally you should see the email associated with your account listed in the status bar at the bottom of VS Code.
Build the app
Building the app locally is required for before a zip deploy because the App Service won't execute build tasks. Build the app however you normally would:
ctrl + shift + b
- kicks off default build in VS Code- execute
npm run build
from a terminal window
Zip deploy from VS Code
- Make sure your app is built, whatever is currently in your
dist
andnode_modules
folders will be the app that is deployed. - Click the blue up arrow (Deploy to Web App) on the Azure App Service section of the explorer window.
- Choose the entire project directory.
If you haven't changed the name, this will be
TypeScript-Node-Starter
. - Choose the subscription you want this app to be billed to (don't worry, it will be free).
- Choose
Create New Web App
- Enter a globally unique name - This will be part of the URL that azure generates so it has to be unique, but if you're planning on adding a custom domain later, it's not that important. I usually just add random numbers to the end of the app name, ie. typescript-node-starter-15121214.
- Choose a resource group - If you don't know what this is, just create a new one. If you have lots of cloud resources that should be logically grouped together (think an app service and a database that supports that app) then you would want to put them in the same resource group. This can always be updated later though. If you create a new resource group, you'll also be prompted to pick a location for that group. Pick something geographically close to where your users are.
- Choose
Create new App Service Plan
- An app service plan mainly is what determines the size and cost of the hardware your app will run on, but it also manages some other settings which we can ignore for now. - Choose
B1 - Basic
- This one is free. If you know what you're doing, feel free to select a stronger pricing tier. - Choose your target node runtime version - We are deploying to Linux machines, and in addition we can choose the exact node runtime we want. If you don't know what you want, choose whatever the current LTS build is.
- Grab a cup of coffee - You'll see everything you just selected getting created in the output window. All of this is powered by the Azure CLI and can be easily replicated if you decide you want to customize this process. This deployment is not the fastest option (but it is the easiest!). We are literally bundling everything in your project (including the massive node_modules folder) and uploading it to our Azure app service. Times will vary, but as a baseline, my deployment took roughly 6 minutes.
- Add
NODE_ENV
environment variable - In the App Service section of the explorer window, expand the newly created service, right click on Application Settings, select Add New Settings..., and addNODE_ENV
as the key andproduction
as the value. This setting determines which database to point to. If you haven't created a cloud database yet, see the setup instructions. - Profit! If everything worked you should see a page that looks like this: TypeScript Node Starter Demo Site
Troubleshooting failed deployments
Deployment can fail for various reasons, if you get stuck with a page that says Service Unavailable or some other error, open an issue and I'll try to help you resolve the problems.
TypeScript + Node
In the next few sections I will call out everything that changes when adding TypeScript to an Express project. Note that all of this has already been setup for this project, but feel free to use this as a reference for converting other Node.js project to TypeScript.
Getting TypeScript
TypeScript itself is simple to add to any project with npm
.
npm install -D typescript
If you're using VS Code then you're good to go!
VS Code will detect and use the TypeScript version you have installed in your node_modules
folder.
For other editors, make sure you have the corresponding TypeScript plugin.
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 test
and views
folders remain top level as expected.
The full folder structure of this app is explained below:
Note! Make sure you have already built the app using
npm run build
Name | Description |
---|---|
.vscode | Contains VS Code specific settings |
dist | Contains the distributable (or output) from your TypeScript build. This is the code you ship |
node_modules | Contains all your npm dependencies |
src | Contains your source code that will be compiled to the dist dir |
src/config | Passport authentication strategies and login middleware. Add other complex config code here |
src/controllers | Controllers define functions that respond to various http requests |
src/models | Models define Mongoose schemas that will be used in storing and retrieving data from MongoDB |
src/public | Static assets that will be used client side |
src/types | Holds .d.ts files not found on DefinitelyTyped. Covered more in this section |
src/server.ts | Entry point to your express app |
test | Contains your tests. Seperate from source because there is a different build process. |
views | Views define how your app renders on the client. In this case we're using pug |
.env.example | API keys, tokens, passwords, database URI. Clone this, but don't check it in to public repos. |
.travis.yml | Used to configure Travis CI build |
.copyStaticAssets.ts | Build script that copies images, fonts, and JS libs to the dist folder |
jest.config.js | Used to configure Jest |
package.json | File that contains npm dependencies as well as build scripts |
tsconfig.json | Config settings for compiling server code written in TypeScript |
tsconfig.tests.json | Config settings for compiling tests written in TypeScript |
tslint.json | Config settings for TSLint code style checking |
Building the project
It is rare for JavaScript projects not to have some kind of build pipeline these days, however Node projects typically have the least amount build configuration. Because of this I've tried to keep the build as simple as possible. If you're concerned about compile time, the main watch task takes ~2s to refresh.
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.
For more complex setups, you can include an exclude
array of glob patterns that removes specific files from the set defined with include
.
There is also a files
option which takes an array of individual file names which overrides both include
and exclude
.
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 |
---|---|
start |
Does the same as 'npm run serve'. Can be invoked with npm start |
build |
Full build. Runs ALL build tasks (build-sass , build-ts , tslint , copy-static-assets ) |
serve |
Runs node on dist/server.js which is the apps entry point |
watch-node |
Runs node with nodemon so the process restarts if it crashes. Used in the main watch task |
watch |
Runs all watch tasks (TypeScript, Sass, Node). Use this if you're not touching static assets. |
test |
Runs tests using Jest test runner |
watch-test |
Runs tests in watch mode |
build-ts |
Compiles all source .ts files to .js files in the dist folder |
watch-ts |
Same as build-ts but continuously watches .ts files and re-compiles when needed |
build-sass |
Compiles all .scss files to .css files |
watch-sass |
Same as build-sass but continuously watches .scss files and re-compiles when needed |
tslint |
Runs TSLint on project files |
copy-static-assets |
Calls script that copies JS libs, fonts, and images to dist directory |
debug |
Performs a full build and then serves the app in watch mode |
serve-debug |
Runs the app with the --inspect flag |
watch-debug |
The same as watch but includes the --inspect flag so you can attach a debugger |
.d.ts
) Files
Type Definition (TypeScript uses .d.ts
files to provide types for JavaScript libraries that were not written in TypeScript.
This is great because once you have a .d.ts
file, TypeScript can type check that library and provide you better help in your editor.
The TypeScript community actively shares all of the most up-to-date .d.ts
files for popular libraries on a GitHub repository called DefinitelyTyped.
Making sure that your .d.ts
files are setup correctly is super important because once they're in place, you get an incredible amount of high quality type checking (and thus bug catching, IntelliSense, and other editor tools) for free.
Note! Because we're using
"noImplicitAny": true
, we are required to have a.d.ts
file for every library we use. While you could setnoImplicitAny
tofalse
to silence errors about missing.d.ts
files, it is a best practice to have a.d.ts
file for every library. (Even if the.d.ts
file is basically empty!)
.d.ts
files from DefinitelyTyped
Installing For the most part, you'll find .d.ts
files for the libraries you are using on DefinitelyTyped.
These .d.ts
files can be easily installed into your project by using the npm scope @types
.
For example, if we want the .d.ts
file for jQuery, we can do so with npm install --save-dev @types/jquery
.
Note! Be sure to add
--save-dev
(or-D
) to yournpm install
..d.ts
files are project dependencies, but only used at compile time and thus should be dev dependencies.
In this template, all the .d.ts
files have already been added to devDependencies
in package.json
, so you will get everything you need after running your first npm install
.
Once .d.ts
files have been installed using npm, you should see them in your node_modules/@types
folder.
The compiler will always look in this folder for .d.ts
files when resolving JavaScript libraries.
What if a library isn't on DefinitelyTyped?
If you try to install a .d.ts
file from @types
and it isn't found, or you check DefinitelyTyped and cannot find a specific library, you will want to create your own .d.ts file
.
In the src
folder of this project, you'll find the types
folder which holds the .d.ts
files that aren't on DefinitelyTyped (or weren't as of the time of this writing).
.d.ts
files in another folder
Setting up TypeScript to look for The compiler knows to look in node_modules/@types
by default, but to help the compiler find our own .d.ts
files we have to configure path mapping in our tsconfig.json
.
Path mapping can get pretty confusing, but the basic idea is that the TypeScript compiler will look in specific places, in a specific order when resolving modules, and we have the ability to tell the compiler exactly how to do it.
In the tsconfig.json
for this project you'll see the following:
"baseUrl": ".",
"paths": {
"*": [
"node_modules/*",
"src/types/*"
]
}
This tells the TypeScript compiler that in addition to looking in node_modules/@types
for every import (*
) also look in our own .d.ts
file location <baseUrl>
+ src/types/*
.
So when we write something like:
import * as flash from "express-flash";
First the compiler will look for a d.ts
file in node_modules/@types
and then when it doesn't find one look in src/types
and find our file express-flash.d.ts
.
dts-gen
Using Unless you are familiar with .d.ts
files, I strongly recommend trying to use the tool dts-gen first.
The README does a great job explaining how to use the tool, and for most cases, you'll get an excellent scaffold of a .d.ts
file to start with.
In this project, bcrypt-nodejs.d.ts
, fbgraph.d.ts
, and lusca.d.ts
were all generated using dts-gen
.
.d.ts
file
Writing a If generating a .d.ts
using dts-gen
isn't working, you should tell me about it first, but then you can create your own .d.ts
file.
If you just want to silence the compiler for the time being, create a file called <some-library>.d.ts
in your types
folder and then add this line of code:
declare module "<some-library>";
If you want to invest some time into making a great .d.ts
file that will give you great type checking and IntelliSense, the TypeScript website has great docs on authoring .d.ts
files.
Contributing to DefinitelyTyped
The reason it's so easy to get great .d.ts
files for most libraries is that developers like you contribute their work back to DefinitelyTyped.
Contributing .d.ts
files is a great way to get into the open source community if it's something you've never tried before, and as soon as your changes are accepted, every other developer in the world has access to your work.
If you're interested in giving it a shot, check out the guidance on DefinitelyTyped. If you're not interested, you should tell me why so we can help make it easier in the future!
.d.ts
management
Summary of In general if you stick to the following steps you should have minimal .d.ts
issues;
- After installing any npm package as a dependency or dev dependency, immediately try to install the
.d.ts
file via@types
. - If the library has a
.d.ts
file on DefinitelyTyped, the install will succeed and you are done. If the install fails because the package doesn't exist, continue to step 3. - Make sure you project is configured for supplying your own
d.ts
files - Try to generate a
.d.ts
file with dts-gen. If it succeeds, you are done. If not, continue to step 5. - Create a file called
<some-library>.d.ts
in yourtypes
folder. - Add the following code:
declare module "<some-library>";
- At this point everything should compile with no errors and you can either improve the types in the
.d.ts
file by following this guide on authoring.d.ts
files or continue with no types. - If you are still having issues, let me know by sending me an email or pinging me on twitter, I will help you.
Debugging
Debugging TypeScript is exactly like debugging JavaScript with one caveat, you need source maps.
Source maps
Source maps allow you to drop break points in your TypeScript source code and have that break point be hit by the JavaScript that is being executed at runtime.
Note! - Source maps aren't specific to TypeScript. Anytime JavaScript is transformed (transpiled, compiled, optimized, minified, etc) you need source maps so that the code that is executed at runtime can be mapped back to the source that generated it.
The best part of source maps is when configured correctly, you don't even know they exist! So let's take a look at how we do that in this project.
Configuring source maps
First you need to make sure your tsconfig.json
has source map generation enabled:
"compilerOptions" {
"sourceMap": true
}
With this option enabled, next to every .js
file that the TypeScript compiler outputs there will be a .map.js
file as well.
This .map.js
file provides the information necessary to map back to the source .ts
file while debugging.
Note! - It is also possible to generate "inline" source maps using
"inlineSourceMap": true
. This is more common when writing client side code because some bundlers need inline source maps to preserve the mapping through the bundle. Because we are writing Node.js code, we don't have to worry about this.
Using the debugger in VS Code
Debugging is one of the places where VS Code really shines over other editors. Node.js debugging in VS Code is easy to setup and even easier to use. This project comes pre-configured with everything you need to get started.
When you hit F5
in VS Code, it looks for a top level .vscode
folder with a launch.json
file.
In this file, you can tell VS Code exactly what you want to do:
{
"type": "node",
"request": "attach",
"name": "Attach by Process ID",
"processId": "${command:PickProcess}",
"protocol": "inspector"
}
This is mostly identical to the "Node.js: Attach by Process ID" template with one minor change.
We added "protocol": "inspector"
which tells VS Code that we're using the latest version of Node which uses a new debug protocol.
With this file in place, you can hit F5
to attach a debugger.
You will probably have multiple node processes running, so you need to find the one that shows node dist/server.js
.
Now just set your breakpoints and go!
Testing
For this project, I chose Jest as our test framework. While Mocha is probably more common, Mocha seems to be looking for a new maintainer and setting up TypeScript testing in Jest is wicked simple.
Install the components
To add TypeScript + Jest support, first install a few npm packages:
npm install -D jest ts-jest
jest
is the testing framework itself, and ts-jest
is just a simple function to make running TypeScript tests a little easier.
Configure Jest
Jest's configuration lives in jest.config.js
, so let's open it up and add the following code:
module.exports = {
globals: {
'ts-jest': {
tsConfigFile: 'tsconfig.json'
}
},
moduleFileExtensions: [
'ts',
'js'
],
transform: {
'^.+\\.(ts|tsx)