Bug – "parserOptions.project" has been set for @typescript-eslint/parser.

TL:DR: Add the file to the "include" array in your tsconfig.json

While setting up Typescript with ESLint, I came across this issue


Parsing error: "parserOptions.project" has been set for @typescript-eslint/parser.
The file does not match your project config: babel.config.js.
The file must be included in at least one of the projects provided

To debug this, I started with the eslintrc.js file where parserOptions was set

module.exports = {
  parser: "@typescript-eslint/parser",
  parserOptions: {
    ecmaVersion: 2020,
    sourceType: "module",
    project: './tsconfig.json', // The error starts here
  },

That field is supposed to point at the tsconfig.json, so it looks correct, but maybe the bug is in that file. I'm only using the typescript engine for static analysis, like an advanced linter, so my tsconfig was a bit immature.

{
  "compilerOptions": {
    "target": "es2020",
    "module": "commonjs",
    "checkJs": true,
    "noEmit": true,
    "strict": true,
    "noImplicitAny": false,
    "baseUrl": "./",
    "paths": {
      "@/*": ["./*"]
    },
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": [".eslintrc.js", "./app/**/*"]
}

The file does not match your project config: babel.config.js. The file must be included in at least one of the projects provided

Since this is the tsconfig.json that the eslintrc.js project field pointed to, I appear to be in the right place and can eliminate all of those words from the error message.

The file does not match your project config: babel.config.js. The file must be included

I see an include array that does not contain this file

{
  "compilerOptions": {
    "target": "es2020",,
    "module": "commonjs",
    "checkJs": true,
    "noEmit": true,
    "strict": true,
    "noImplicitAny": false,
    "baseUrl": "./",
    "paths": {
      "@/*": ["./*"]
    },
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": [
    ".eslintrc.js",
    "./app/**/*",
+   "./babel.config.js",
+   "./jest.config.js"
  ]
}

I was also getting the error for jest.config.js, so I added that one as well. After restarting eslint, the error has gone away, so this fix appears to be succesful.