Add TS server command for removing all unused code in a file

Search terms

• code action
• source action
• getCombinedCodeFix

Feature request

Add a new TS Server command that removes all unused code in a file. This should only perform 'safe' removals, such as:

• Unreachable code
• Unused imports
• Unused declarations

We should likely not remove unused parameters. Not sure about removing unused variable since removing them can also have side effects

Use case

VS Code allows users to configure code actions that are run on save. One of the supported code actions is source.removeUnused which attempts to remove unused code in a file

On the VS Code side, we can't implement this very well since unused code often ends up overlapping with other unused code and we don't have much insight into what is "safe" to remove and what is not

まず、既存の TS Server コマンドと issue で言及されている getCombinedCodeFix パスを読み、次に VS Code が source.removeUnused をどのように呼び出しているかを比較します。完了条件は、コマンドが安全な到達不能コード、未使用の import、未使用の宣言だけを削除し、パラメーターと副作用を持つ可能性のある変数はそのまま残すことです。