tsc cannot find name `Set` with jest

Question

I have typescript compilation setup, and compiling works perfectly.

I then install jest (a testing framework) as a devDependency. This is for development only (hence why it is a devDependency), and shouldn't be part of the compiled package.

Compilation now results in the following error:

node_modules/@types/babel__template/index.d.ts:16:28 - error TS2583: Cannot find name 'Set'. Do you need to change your target library? Try changing the `lib` compiler option to es2015 or later.

16     placeholderWhitelist?: Set<string>;

• Can this error be solved, and if so, how? Adding "lib": ["es6"] is not am acceptable solution, as an implementation details of jest should not require me to modify my compiler options like this. Also note that jest runs perfectly. If there is no other solution, then that's an acceptable answer.

• Why is tsc compiling devDependencies and how do I stop this? I don't see why I should suddenly have to worry about the nested babel devDependency affecting my compilation.

---

Edit: tsconfig.json

{
  "compilerOptions": {
        "target": "es5",
        "module": "commonjs",
        "sourceMap": true,
        "rootDir": "./src",
        "outDir": "./build",

        "strict": true,
        "esModuleInterop": true
    },
    "include": [
        "src/**/*"
    ],
    "exclude": [
        "/src/**/?(*.)test.ts"
    ]
}

---

Note: This is not a duplicate of node_modules/@types/babel _template/index.d.ts :16:28 - error TS2583: Cannot find name 'Set'

This question was asking why tsc is looking in node_modules which is different from my questions (and the accepted answer is for that question).

Answer 1

Why is tsc compiling devDependencies and how do I stop this? I don't see why I should suddenly have to worry about the nested babel devDependency affecting my compilation.

By default, tsc loads all the declarations in node_modules/@types/**/*, which in your case, includes a type declaration that depends on >= es2015. If that type declaration came from a devDependency, then tsc will include it. That's why tsc is compiling something associated with a devDependency.

If upgrading to es2015 is not a valid solution, then you can also try ignoring the specific type declaration that depends on it.

From the TypeScript documentation on @types:

By default all visible “@types” packages are included in your compilation... Specify "types": [] to disable automatic inclusion of @types packages.

Answer 2

Considering your tsconfig you can:

• add lib to your compilerOptions, but you don't want impact your project because of a test lib, I understand that;

• make sure your tests use another tsconfig, like a tsconfig.test.json which have the needed lib => I think it's your solution;