moveToNewFile: move variable under cursor

Search Terms

Move to New File
Refactor Refactoring

Suggestion

Allow selecting variable name, not only function/class name, in moveToNewFile refactoring.

Use Cases

moveToNewFile is useful for refactoring React component.
React component can be written in both function statements and arrow functions (function assigned to variable).
But current moveToNewFile implementation requires whole lines of a variable statement to be selected, while function and class can be moved by launching Quick Fix at their name.

Examples

function Component(props: Props) {
  ...
}

Currently, when placing cursor at anywhere in function or class name, i.e. Component in above, VSCode shows "Move to New File" menu. But if it is variable, the menu does not show up.

// Cannot refactor until selecting all lines of below statement.
// I want to refactor this by moving cursor to anywhere in "Component"
const Component: React.FC<Props> = (props: Props) => {
  ...
}

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Implementation

https://github.com/microsoft/TypeScript/compare/master...ypresto:move-var-func-to-new-file?expand=1

まず、リファクタリングのエントリーポイントである moveToNewFile と、issue の比較 URL にリンクされている実装を確認します。関数名とクラス名がどのように認識されるかを追跡し、次に React コンポーネントの宣言のような変数名に何が必要かを判断します。既存の動作を維持したまま、変数名にカーソルを置いたときに Quick Fix が表示されれば完了です。