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Sean Johnson
Sean Johnson

Posted on • Updated on

Create a TypeScript project

Creating a TypeScript project is easy!

Let's get up and running with build and testing scripts!

You will need a few things first:

Create your project folder

Create a folder with your project's name in [[Project Name]].

NOTE: Node.js convention is to use kebab-case. All letters are lower case, and dashes are used for spaces.

Run the following command:

mkdir [[Project Name]]
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Open with an Editor

The following example is for Visual Studio Code. It will likely be similar for other editors.

Open your folder in Visual Studio Code. Open Visual Studio Code, then navigate to File -> Open Folder....

Alternatively, if you have the shortcut set up, you can run the following command:

code [[Project Name]]
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Once in the editor, open the Integrated Terminal to continue. Navigate to View -> Terminal, or use the Keyboard Shortcut Ctrl + ` or Cmd + `.

Continue in the system terminal

Alternatively, change directory into the folder in the current terminal:

cd [[Project Name]]
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Install Dependencies

Create your package.json, which stores NPM configuration.

NOTE: When prompted, it is HIGHLY recommended to start with version 0.0.0 or 0.0.1.

This implies that the project is in development. Starting with 1.0.0 implies the project is stable.

Run the following command:

npm init
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Install TypeScript and Jest as "devDependencies" in package.json. This will also create a package-lock.json file, which stores specific package version information.

Run the following command:

npm i -D typescript jest ts-jest @types/jest
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Configure TypeScript

Creates your tsconfig.json file, which stores TypeScript configuration.

Run the following command:

npx tsc --init
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Creates your src/index.ts file.

Run the following commands:

mkdir src
touch ./src/index.ts
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In tsconfig.json, update the following "compilerOptions". This configures TypeScript to use your source files, and generate all of the necessary declaration and map files. It also enabled ES Modules.

  "module": "ESNext",
  "rootDir": "./src",
  "moduleResolution": "node",
  "declaration": true,
  "declarationMap": true,
  "sourceMap": true,
  "outDir": "./dist",
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In package.json, create the following properties. This configures your package to use the TypeScript generated files. It also enabled ES Modules.

  "type": "module",
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
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Configure Scripts

In package.json, create the following "scripts". These are common scripts for building and testing.

  "scripts": {
    "test": "jest",
    "start": "tsc --watch",
    "build": "tsc",
    "clean": "tsc --build --clean",
    "prepublishOnly": "tsc --build --clean && tsc"
  }
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In package.json, add the following section. This tells Jest how to find and run your TypeScript tests.

  "jest": {
    "preset": "ts-jest",
    "testPathIgnorePatterns": [
      "<rootDir>/dist/"
    ]
  }
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Configure Git

Create your Git configuration. It is important to check in only source files.

Run the following commands:

git init
touch .gitignore
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Add the following to .gitignore. This will prevent checking in TypeScript generated files.

node_modules/
dist/
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Configure NPM publish

Create your NPM publish configuration. It is important to publish BOTH source files, and TypeScript generated files.

Run the following command:

touch .npmignore
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Add the following to .npmignore. This will prevent checking in unnecessary files.

NOTE: Do not include dist/ or src/ in your .npmignore file.

tsconfig.json
.gitignore
.npmignore
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