use hir::db::HirDatabase; use ra_syntax::{algo::non_trivia_sibling, Direction, T}; use crate::{Assist, AssistCtx, AssistId}; // Assist: flip_comma // // Flips two comma-separated items. // // ``` // fn main() { // ((1, 2),<|> (3, 4)); // } // ``` // -> // ``` // fn main() { // ((3, 4), (1, 2)); // } // ``` pub(crate) fn flip_comma(mut ctx: AssistCtx) -> Option { let comma = ctx.find_token_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; } ctx.add_action(AssistId("flip_comma"), "flip comma", |edit| { edit.target(comma.text_range()); edit.replace(prev.text_range(), next.to_string()); edit.replace(next.text_range(), prev.to_string()); }); ctx.build() } #[cfg(test)] mod tests { use super::*; use crate::helpers::{check_assist, check_assist_target}; #[test] fn flip_comma_works_for_function_parameters() { check_assist( flip_comma, "fn foo(x: i32,<|> y: Result<(), ()>) {}", "fn foo(y: Result<(), ()>,<|> x: i32) {}", ) } #[test] fn flip_comma_target() { check_assist_target(flip_comma, "fn foo(x: i32,<|> 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,<|> \ }", ",", ); check_assist_target( flip_comma, "pub struct Test { \ foo: usize,<|> \ }", ",", ); } }