Bug: [no-unnecessary-type-assertion] errors not reported when using unnecessary literal assertions on const variable declarations

[abrahamguo]

Before You File a Bug Report Please Confirm You Have Done The Following...

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

Playground Link

https://typescript-eslint.io/play#eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6Jge1tiacTJTIAhtEK0ipWkOTJE0fJQ5N0UOdA7RI4MAF8QOoA&code=MYewdgzgLgBAZiEMC8MA8BmAfBg3EA

Repro Code

const foo = <3>3;

ESLint Config

module.exports = {
  parser: "@typescript-eslint/parser",
  rules: {
    "@typescript-eslint/no-unnecessary-type-assertion": "error"
  },
};

tsconfig

{}

Expected Result

3 should be reported as an unnecessary type assertion, since removing it has no effect.

Actual Result

The type assertion was not reported.

Additional Info

Raised originally in #8458 and solution opened in #8558. Breaking this out from the original issue into a separate issue.

[auvred]

Look like a duplicate of #4485

[bradzacher]

This is working as intended.

Its not always safe to remove an assertion to a literal type as there are cases where TS will widen the type - so the rule ignores assertions to literal types (and tuple types).

example widening case.

[bradzacher]

100% right @auvred - duplicate of #4485