Compiler options

Typically, the first step in a new TypeScript project is to add in a tsconfig.json file. This file defines the project and compiler settings, for instance, files and libraries to be included in the compilation, output structure, module code generation, and so on. A typical configuration in tsconfig.json for Angular 2+ projects looks like the following:

{
  "compilerOptions": {
    "target": "es5",
    "module": "es2015",
    "moduleResolution": "node",
    "noImplicitAny": true,
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "outDir": "dist",
    "lib": ["es2015", "dom"]
  },
  "types": ["node"],
  "exclude": ["node_modules", "dist"]
}

The listed compiler settings are described as follows. A full list of all options is available at the TypeScript documentation page (https://www.typescriptlang.org/docs/handbook/compiler-options.html).

Option	Type	Default	Description
target	string	ES3	This specifies ECMAScript target version: ES3, ES5, ES2015, ES2016, and ES2017.
module	string	ES6 if target is "ES6" and CommonJS otherwise	This specifies the format of module code generation: None, CommonJS, AMD, System, UMD, ES6, or ES2015.
moduleResolution	string	Classic if module is "AMD," System, ES6, and Node otherwise	This determines how modules get resolved. Either Node for Node.js style resolution or Classic.
noImplicitAny	boolean	false	This raises errors on expressions and declarations with an implied any type.
sourceMap	boolean	false	This generates the corresponding .map file. This is useful if you want to debug original files.
emitDecoratorMetadata	boolean	false	This emits design type metadata for decorated declarations in source. You have to set this value to true if you want to develop web applications with Angular.
experimentalDecorators	boolean	false	This enables experimental support for ECMAScript decorators. You have to set this value to true if you want to develop web applications with Angular.
outDir	string	-	This is the output directory for compiled files.
lib	string[]	Refer to the documentation for more information.	This is the list of library files to be included in the compilation. Refer to the documentation for more information.
types	string[]	-	This is the list of names of type definitions to include.
exclude	string[]	-	This is the list of (sub) directories excluded from the compilation.

You can stop the compiler from emitting JavaScript on errors by setting the --noEmitOnError option to true.