function unthunk(expression) {
	if (
		expression.type === 'ArrowFunctionExpression' &&
		expression.async === false &&
		expression.body.type === 'CallExpression' &&
		expression.body.callee.type === 'Identifier' &&
		expression.params.length === expression.body.arguments.length &&
		expression.params.every((param, index) => {
			const arg = /** @type {ESTree.SimpleCallExpression} */ (expression.body).arguments[index];
			return param.type === 'Identifier' && arg.type === 'Identifier' && param.name === arg.name;
		})
	) {
		return expression.body.callee;
	}
	return expression;
}
Replace "(arg) => func(arg)" to "func"
@param {ESTree.Expression} expression
@returns {ESTree.Expression}