How to solve the issue TS2451: Cannot redeclare block-scoped variable 'I'

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Working with CodeceptJS and TypeScript offers several benefits, but it can also come with a headache issue, which is the TS2451: Cannot redeclare block-scoped variable 'I' error.

Screen Shot 2023-04-26 at 7.03.36 AM

If you encounter this issue, there are a few ways to overcome it. One approach is to add export {} at the beginning of your test file, but this would require adding it to multiple files as your project expands.

A more elegant solution is to edit your tsconfig.json. One option that immediately solves the problem and eliminates the need to manipulate multiple files is to add "moduleDetection": "force" to the "compilerOptions" section, as shown in the example below:

{
  "ts-node": {
    "files": true
  },
  "compilerOptions": {
    "target": "es2018",
    "lib": ["es2018", "DOM"],
    "esModuleInterop": true,
    "module": "commonjs",
    "strictNullChecks": false,
    "types": ["codeceptjs", "node"],
    "declaration": true,
    "skipLibCheck": true,
    "moduleDetection": "force" // <<<<< adding this 
  },
  "exclude": ["node_modules"]
}

Note that for TypeScript 4.7+, this option is documented under: https://www.typescriptlang.org/tsconfig#moduleDetection

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