Why do I have to specify types in tsconfig.json if type definitions are already in package.json-CodePudding

I have "@types/gapi.client.gmail": "~1.0.3" in package.json.

I also had this in tsconfig.json:

  "types": [
    "jest",
    "gapi",
    "gapi.auth2",
    "gapi.client.docs"
  ],

I can't recall why those statements are there. But now that I am adding gmail support to my app, I want to understand why I need to add gmail to this type array, so it becomes:

  "types": [
    "jest",
    "gapi",
    "gapi.auth2",
    "gapi.client.docs",
    "gapi.client.gmail"
  ],

Without this addition, I get:

TS2339: Property 'gmail' does not exist on type 'typeof client'.

Why do I have to add types to the tsconfig array if they types are already declared in package.json as dependencies?

CodePudding user response：

When you define your types like that, only the types in the list will be imported, and not all of the available types under your node_modules.

Relevant docs- https://www.typescriptlang.org/tsconfig#types