Bug: [switch-exhaustiveness-check] conflicts with no-unnecessary-condition on switching `true`

[Rusty-Beard]

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• [X] I have tried restarting my IDE and the issue persists.
• [X] I have updated to the latest version of the packages.
• [X] I have searched for related issues and found none that matched my issue.
• [X] I have read the FAQ and my problem is not listed.

Playground Link

https://typescript-eslint.io/play/#ts=5.6.2&fileType=.ts&code=MYewdgzgLgBBIFsCmA5ArggRkgTgLhjA2xxgF4YBGAbgChbRJYoloAxNMYS8mACgCUBIllzkAfDADetGHADuASyjAAFvyg40SAdJgB6fTCQAPAA5JgLACbGcOEKQBmjmFFVIYwNPaRhY2KoAhgBuio6ycl5BEJ7wyOiipGQpVHiRUTA4SFA%2BYFR0mdZITkFoADZQ6Zly2bk4%2BQBMhTAAvrTttPoAVLQABsAxnprafVlIZuVBwKwwAOTFpRVQczCYOEFcqgA0a2jMAJ4WEMA4imaw1iCsYHOwANZgIPIwQZgg%2B27BsLLd%2BgzgaBuVhQDhcRq8QTCYhiMiSKQwSIQJQqdR8EY6aQZaKxOCIVAw5KpSjVGp1PIFbGGVjlRT%2BAC01kUEDe5SQ9LApig9NpnJgAAEoEdWKdztyaXSoPonvTOJyZhAWTgDvTGEyoOEwNjBriMaTMuSGjBmpF2p0erQAMoWYCKJwHOkAcy%2BzLWGy2sygIEdOQ8pCU5XKePKIWGHle71DMDMDkwbIQu0wn2UXnATlpVggMBRqloguFJzOF3pEv80pAsrA8tYSpVauUmqyFSQv3%2BjCBLHYnGAAGZIUJCISJFi5MjlGoNFpMTJMjq4vjEiRyMT9VFDfkaPRZ0M3FOCNjFmVKqvajkKSa5GagA&eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6ZAd0vzIAt6AHrwCGsZPkoA3RExTJafRGQDW6KImjQA9tEgAacNjxFSyCtToNmbJltqwmssnOHRCCrUwAm3Sp7WQGtq6hgC%2BIKFAA&tsconfig=N4KABGBEDGD2C2AHAlgGwKYCcDyiAuysAdgM6QBcYoEEkJemy0eAcgK6qoDCAFutAGsylBm3TgwAXxCSgA&tokens=false

Repro Code

const someNumber: number = 1;
const testFunc = (): number => {
  switch (true) {
    case someNumber === 1:
      return 1;

    case true: 
    default:
      return 2;
  }
}

ESLint Config

module.exports = {
  parser: "@typescript-eslint/parser",
  rules: {
    "@typescript-eslint/switch-exhaustiveness-check": "error",
    "@typescript-eslint/no-unnecessary-condition": "error"
  },
};

tsconfig

{
  "compilerOptions": {
    "strictNullChecks": true
  }
}

Expected Result

considerDefaultExhaustiveForUnions option is implicitly enabled for switch (true) or switch (false) statements

Actual Result

It forces you to specify the case true branch with the disabled considerDefaultExhaustiveForUnions option (by default). At the same time, this conflicts with the no-unnecessary-condition rule.

Additional Info

No response

[kirkwaiblinger]

Hi @Rusty-Beard!

Is there a reason not to write this as

const someNumber: number = 1;
const testFunc = (): number => {
    if (someNumber === 1) {
        return 1;
    } else {
        return 2;
    }

I see that the lint rules are preventing you from writing each of the provided examples in the playground link... but I don't quite follow why any of them should be allowed.