extensions/typescript-language-features/src/languageFeatures/jsDocCompletions.ts/JsDocCompletionProvider/isPotentiallyValidDocCompletionPosition
class JsDocCompletionProvider:	private isPotentiallyValidDocCompletionPosition(
		document: vscode.TextDocument,
		position: vscode.Position
	): boolean {
		// Only show the JSdoc completion when the everything before the cursor is whitespace
		// or could be the opening of a comment
		const line = document.lineAt(position.line).text;
		const prefix = line.slice(0, position.character);
		if (!/^\s*$|\/\*\*\s*$|^\s*\/\*\*+\s*$/.test(prefix)) {
			return false;
		}

		// And everything after is possibly a closing comment or more whitespace
		const suffix = line.slice(position.character);
		return /^\s*(\*+\/)?\s*$/.test(suffix);
	}