How not to include internal code in ts declaration file

Typescript provides a mechanism to not include internal code in a declaration file. It can be useful for building a public library.

We can use the stripInternal: true property in our tsconfig.json file. This will enable typescript compiler to check the /** @internal */ JS DOC comment.

main.ts

Add the /** @internal */ JS DOC comment .
By default typescript compiler will ignore this comment but we can enable it in tsconfig.json file.

/** @internal */
function init() {
  console.log('Hello!!')
}

In tsconfig.json

{
  "compilerOptions": {
    "outDir": "./dist",
    "declaration": true,
    "stripInternal": true
  }
}

Compile and check your declaration main.d.ts(in this case it will have the same name as main.ts file) file to not include the init function declaration.