Writing a Configuration File

Writing a Configuration File

TypeScript uses a file called tsconfig.json for managing your project’s options, such as which files you want to include, and what sorts of checking you want to perform. Let’s create a bare-bones one for our project:

{
  "compilerOptions": {
    "outDir": "./built",
    "allowJs": true,
    "target": "es5"
  },
  "include": [
    "./src"
  ]
}

Here we’re specifying a few things to TypeScript:

1. Read in any files it understands in the src directory (with include).
2. Accept JavaScript files as inputs (with allowJs).
3. Emit all of the output files in built (with outDir).
4. Translate newer JavaScript constructs down to an older version like ECMAScript 5 (using target).

At this point, if you try running tsc at the root of your project, you should see output files in the built directory. The layout of files in built should look identical to the layout of src. You should now have TypeScript working with your project.