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|
use hir::db::HirDatabase;
use ra_syntax::{
ast::{AstNode, BinExpr, BinOp}
};
use crate::{AssistCtx, Assist, AssistId};
pub(crate) fn flip_eq_operands(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
let expr = ctx.node_at_offset::<BinExpr>()?;
let allowed_ops = [BinOp::EqualityTest, BinOp::NegatedEqualityTest];
let expr_op = expr.op()?;
if ! allowed_ops.iter().any(|o| *o == expr_op) {
return None;
}
let node = expr.syntax();
let prev = node.first_child()?;
let next = node.last_child()?;
ctx.add_action(AssistId("flip_eq_operands"), "flip equality operands", |edit| {
edit.target(node.range());
edit.replace(prev.range(), next.text());
edit.replace(next.range(), prev.text());
});
ctx.build()
}
#[cfg(test)]
mod tests {
use super::*;
use crate::helpers::{check_assist, check_assist_target};
#[test]
fn flip_eq_operands_for_simple_stmt() {
check_assist(
flip_eq_operands,
"fn f() { let res = 1 ==<|> 2; }",
"fn f() { let res = 2 ==<|> 1; }",
)
}
#[test]
fn flip_neq_operands_for_simple_stmt() {
check_assist(
flip_eq_operands,
"fn f() { let res = 1 !=<|> 2; }",
"fn f() { let res = 2 !=<|> 1; }",
)
}
#[test]
fn flip_eq_operands_for_complex_stmt() {
check_assist(
flip_eq_operands,
"fn f() { let res = (1 + 1) ==<|> (2 + 2); }",
"fn f() { let res = (2 + 2) ==<|> (1 + 1); }",
)
}
#[test]
fn flip_eq_operands_in_match_expr() {
check_assist(
flip_eq_operands,
r#"
fn dyn_eq(&self, other: &dyn Diagnostic) -> bool {
match other.downcast_ref::<Self>() {
None => false,
Some(it) => it ==<|> self,
}
}
"#,
r#"
fn dyn_eq(&self, other: &dyn Diagnostic) -> bool {
match other.downcast_ref::<Self>() {
None => false,
Some(it) => self ==<|> it,
}
}
"#,
)
}
#[test]
fn flip_eq_operands_target() {
check_assist_target(flip_eq_operands, "fn f() { let res = 1 ==<|> 2; }", "1 == 2")
}
}
|
