Cấu hình với tsconfig.json

The tsconfig.json file specifies the root directory of a TypeScript project and the compiler options required to build the project.

Whenever you run tsc in a project directory, the compiler searches for this file to guide its compilation behavior.

Structure of a tsconfig.json File

A typical configuration file looks like this:

{
  "compilerOptions": {
    "target": "es2022",
    "module": "commonjs",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "outDir": "./dist"
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "**/*.spec.ts"]
}

The main properties are:

• compilerOptions: Settings for the compiler.
• include: Specifies the files or folders to compile.
• exclude: Specifies the files or folders to ignore during compilation.

Key Compiler Options

Here are some of the most important settings to know:

1. target: Specifies the version of JavaScript output by the compiler (e.g., es5, es6/es2015, es2020, esnext).
2. module: Specifies the module system used in the compiled code (e.g., commonjs, esnext, node16).
3. strict: Enables a broad suite of rigorous type-checking behaviors. It is highly recommended to set this to true for maximum type safety. It enables options like:
   • noImplicitAny: Raises an error on expressions and declarations with an implied any type when no type annotation is provided.
   • strictNullChecks: Prevents assigning null or undefined to types that do not explicitly include them in their union.

Try it yourself

Exercise 1: Handling strictNullChecks

Exercise 2: Strict Typing without Implicit Any