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 havesearched for related issues and found none that matched my issue.
• I haveread the FAQ and my problem is not listed.

Playground Link

https://typescript-eslint.io/play/#ts=5.6.3&fileType=.tsx&code=LAKAJgpgxgNghgJwgAgGYFcB2UAuBLAe0zQIIAoBKALmU3QFsAjCBZAH2S0lT0wjFCRYiFBmz4iyRoko06TFoOjwkaLLkLFpALzKY5DZgmrIAbgTxgA3KFBiNk%2BnF4BGSsgDeoZMhgQcyAAeNiA%2BgcgAvFIyFCFhkSTksd7RuoEAhMkgAL62IPYSxE68AEzuXqG%2B-kFxQQnSCJS14VGopE0pOmSBWbkgQA&eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6Jge1tiacTJTIAhtEK0ipWkOTJE0fJQ5N0UOdA7RI4MAF8QOoA&tsconfig=N4KABGBEDGD2C2AHAlgGwKYCcDyiAuysAdgM6QBcYoEEkJemy0eFYDArugDTg10NM8AOXapUAYQAW6aAGsylDul4BfECqA&tokens=false

Repro Code

declarefunctionfoo():number|undefineddeclarefunctionbar():numberdeclarefunctionbaz(n:number):void;functionmain1(){letx;x=bar();x=foo();baz(x!);}functionmain2(){letx;x=bar();x=foo();baz(x);}

ESLint Config

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

tsconfig

{"compilerOptions": {"strict":true  }}

Expected Result

The linter should not treatbaz(x!) as an unnecessary type assertion

Actual Result

@typescript-eslint/no-unnecessary-type-assertion rule warns about the assertion baz(x!) as unnecessary, suggesting it could be removed. Removing the assertion causes TypeScript to raise an error.

Additional Info

No response