use syntax::{algo::non_trivia_sibling, Direction, T}; use crate::{AssistContext, AssistId, AssistKind, Assists}; // Assist: flip_comma // // Flips two comma-separated items. // // ``` // fn main() { // ((1, 2),$0 (3, 4)); // } // ``` // -> // ``` // fn main() { // ((3, 4), (1, 2)); // } // ``` pub(crate) fn flip_comma(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { let comma = ctx.find_token_syntax_at_offset(T![,])?; let prev = non_trivia_sibling(comma.clone().into(), Direction::Prev)?; let next = non_trivia_sibling(comma.clone().into(), Direction::Next)?; // Don't apply a "flip" in case of a last comma // that typically comes before punctuation if next.kind().is_punct() { return None; } acc.add( AssistId("flip_comma", AssistKind::RefactorRewrite), "Flip comma", comma.text_range(), |edit| { edit.replace(prev.text_range(), next.to_string()); edit.replace(next.text_range(), prev.to_string()); }, ) } #[cfg(test)] mod tests { use super::*; use crate::tests::{check_assist, check_assist_target}; #[test] fn flip_comma_works_for_function_parameters() { check_assist( flip_comma, "fn foo(x: i32,$0 y: Result<(), ()>) {}", "fn foo(y: Result<(), ()>, x: i32) {}", ) } #[test] fn flip_comma_target() { check_assist_target(flip_comma, "fn foo(x: i32,$0 y: Result<(), ()>) {}", ",") } #[test] #[should_panic] fn flip_comma_before_punct() { // See https://github.com/rust-analyzer/rust-analyzer/issues/1619 // "Flip comma" assist shouldn't be applicable to the last comma in enum or struct // declaration body. check_assist_target( flip_comma, "pub enum Test { \ A,$0 \ }", ",", ); check_assist_target( flip_comma, "pub struct Test { \ foo: usize,$0 \ }", ",", ); } }