ESLint fails to generate an eslintrc file when I ask it to analyse my TypeScript based project

[rajat1saxena]

Tell us about your environment
Ubuntu 18.04
Environment Info:

Node version: v12.16.1
npm version: v6.14.4
Local ESLint version: Not found
Global ESLint version: Not found

• ESLint Version: 6.8.0
• Node Version: v12.16.1
• npm Version: 6.14.4

What parser (default, Babel-ESLint, etc.) are you using? typescript-parser

Please show your full configuration:

Configuration

{
  "name": "eslinttest",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@typescript-eslint/eslint-plugin": "^2.26.0",
    "@typescript-eslint/parser": "^2.26.0",
    "eslint": "^6.8.0",
    "typescript": "^3.8.3"
  }
}

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.
I was trying to initialize ESLint for a TypeScript based project. I wanted to let ESLint to analyse my code base and set itself up accordingly. Following are the options I chose.

? How would you like to use ESLint? To check syntax, find problems, and enforce code style
? What type of modules does your project use? JavaScript modules (import/export)
? Which framework does your project use? None of these
? Does your project use TypeScript? Yes
? Where does your code run? Node
? How would you like to define a style for your project? Inspect your JavaScript file(s)
? Which file(s), path(s), or glob(s) should be examined? src/*.ts
? What format do you want your config file to be in? JavaScript
Determining Config: 100% [==============================] 0.1s elapsed, eta 0.0s 
Determining Config: 100% [==============================] 0.2s elapsed, eta 0.0s 

Enabled 275 out of 275 rules based on 1 file.
config.extends.push is not a function
TypeError: config.extends.push is not a function
    at processAnswers (/home/guest/dev/opensource/eslint/node_modules/eslint/lib/init/config-initializer.js:330:24)
    at /home/guest/dev/opensource/eslint/node_modules/eslint/lib/init/config-initializer.js:614:28
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

What did you expect to happen?
It should create a .eslintrc.js file.

What actually happened? Please include the actual, raw output from ESLint.
I got the above mentioned error and no eslintrc.js was generated

Are you willing to submit a pull request to fix this bug?
Yes

[mdjermanovic]

Hi @rajat1saxena, thanks for the bug report!

I think this is a duplicate of #12707, which will be fixed by PR #12738.

[mdjermanovic]

Closing this as it's fixed by #12738 (merged now).