Misleading error message for duplicate CLI flags

Bug Report

🔎 Search Terms

tsc multiple flag options cli

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about CLI option parsing

⏯ Playground Link

N/A

💻 Code

Any of:

tsc -b -b
tsc -b --build
tsc -b --clean --build

🙁 Actual behavior

tsc -b -b      
error TS5072: Unknown build option '-b'.

🙂 Expected behavior

Something indicating the flag was provided twice, not that it's unknown?

tsc -b -b      
error TS5072: Duplicate build option '-b' provided.

報告されたコマンド tsc -b -b、tsc -b --build、tsc -b --clean --build を使って、まず TypeScript の CLI オプション解析を追跡します。現在の診断を、重複したオプションに対して期待される文言と比較します。重複した build フラグが不明なオプションではなく重複として報告されれば完了です。