tsconfig.json

{
  "compilerOptions": {
    "lib": ["es2017", "es7", "es6", "dom"], // specifies which default set of type definitions to use ("DOM", "ES6", etc)
    "outDir": "lib", // .js (as well as .d.ts, .js.map, etc.) files will be emitted into this directory.,
    "removeComments": true, // Strips all comments from TypeScript files when converting into JavaScript- you rarely read compiled code so this saves space
    "target": "es6", // Target environment
    "declaration": true, // Generate .d.ts files such that it can be imported in a ts project

    // Module resolution
    "module": "commonjs",
    "baseUrl": "./", // Lets you set a base directory to resolve non-absolute module names.
    "esModuleInterop": true, // fixes some issues TS originally had with the ES6 spec where TypeScript treats CommonJS/AMD/UMD modules similar to ES6 module
    "moduleResolution": "node", // Pretty much always node for modern JS. Other option is "classic"
    "resolveJsonModule": true, // Allows direct json imports

    // Source Map
    "sourceMap": true, // enables the use of source maps for debuggers and error reporting etc
    "sourceRoot": "/", // Specify the location where a debugger should locate TypeScript files instead of relative source locations.

    // Linter Checks
    "alwaysStrict": true, // Ensures that your files are parsed in the ECMAScript strict mode, and emit “use strict” for each source file.
    "allowUnreachableCode": false, // pick up dead code paths
    "strictNullChecks": true, // When strictNullChecks is true, null and undefined have their own distinct types and you’ll get a type error if you try to use them where a concrete value is expected.
    "noUnusedLocals": true, // Report errors on unused local variables.
    "noUnusedParameters": true, // Report errors on unused parameters in functions
    "noImplicitAny": true, // In some cases where no type annotations are present, TypeScript will fall back to a type of any for a variable when it cannot infer the type.
    "skipLibCheck": true // Skip checks on node_modules/
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules"]
}