rust/crates/ra_assists/src/assists/flip_comma.rs
2019-09-25 14:29:41 +03:00

69 lines
1.9 KiB
Rust

use hir::db::HirDatabase;
use ra_syntax::{algo::non_trivia_sibling, Direction, T};
use crate::{Assist, AssistCtx, AssistId};
pub(crate) fn flip_comma(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
let comma = ctx.token_at_offset().find(|leaf| leaf.kind() == 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,<|> \
}",
",",
);
}
}