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|
use ra_syntax::{
ast,
ast::{AstNode, AstToken, IfExpr, MatchArm},
TextSize,
};
use crate::{Assist, AssistCtx, AssistId};
// Assist: move_guard_to_arm_body
//
// Moves match guard into match arm body.
//
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// match action {
// Action::Move { distance } <|>if distance > 10 => foo(),
// _ => (),
// }
// }
// ```
// ->
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// match action {
// Action::Move { distance } => if distance > 10 { foo() },
// _ => (),
// }
// }
// ```
pub(crate) fn move_guard_to_arm_body(ctx: AssistCtx) -> Option<Assist> {
let match_arm = ctx.find_node_at_offset::<MatchArm>()?;
let guard = match_arm.guard()?;
let space_before_guard = guard.syntax().prev_sibling_or_token();
let guard_conditions = guard.expr()?;
let arm_expr = match_arm.expr()?;
let buf = format!("if {} {{ {} }}", guard_conditions.syntax().text(), arm_expr.syntax().text());
ctx.add_assist(AssistId("move_guard_to_arm_body"), "Move guard to arm body", |edit| {
edit.target(guard.syntax().text_range());
let offseting_amount = match space_before_guard.and_then(|it| it.into_token()) {
Some(tok) => {
if ast::Whitespace::cast(tok.clone()).is_some() {
let ele = tok.text_range();
edit.delete(ele);
ele.len()
} else {
TextSize::from(0)
}
}
_ => TextSize::from(0),
};
edit.delete(guard.syntax().text_range());
edit.replace_node_and_indent(arm_expr.syntax(), buf);
edit.set_cursor(
arm_expr.syntax().text_range().start() + TextSize::from(3) - offseting_amount,
);
})
}
// Assist: move_arm_cond_to_match_guard
//
// Moves if expression from match arm body into a guard.
//
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// match action {
// Action::Move { distance } => <|>if distance > 10 { foo() },
// _ => (),
// }
// }
// ```
// ->
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// match action {
// Action::Move { distance } if distance > 10 => foo(),
// _ => (),
// }
// }
// ```
pub(crate) fn move_arm_cond_to_match_guard(ctx: AssistCtx) -> Option<Assist> {
let match_arm: MatchArm = ctx.find_node_at_offset::<MatchArm>()?;
let match_pat = match_arm.pat()?;
let arm_body = match_arm.expr()?;
let if_expr: IfExpr = IfExpr::cast(arm_body.syntax().clone())?;
let cond = if_expr.condition()?;
let then_block = if_expr.then_branch()?;
// Not support if with else branch
if if_expr.else_branch().is_some() {
return None;
}
// Not support moving if let to arm guard
if cond.pat().is_some() {
return None;
}
let buf = format!(" if {}", cond.syntax().text());
ctx.add_assist(
AssistId("move_arm_cond_to_match_guard"),
"Move condition to match guard",
|edit| {
edit.target(if_expr.syntax().text_range());
let then_only_expr = then_block.statements().next().is_none();
match &then_block.expr() {
Some(then_expr) if then_only_expr => {
edit.replace(if_expr.syntax().text_range(), then_expr.syntax().text())
}
_ => edit.replace(if_expr.syntax().text_range(), then_block.syntax().text()),
}
edit.insert(match_pat.syntax().text_range().end(), buf);
edit.set_cursor(match_pat.syntax().text_range().end() + TextSize::from(1));
},
)
}
#[cfg(test)]
mod tests {
use super::*;
use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
#[test]
fn move_guard_to_arm_body_target() {
check_assist_target(
move_guard_to_arm_body,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' <|>if chars.clone().next() == Some('\n') => false,
_ => true
}
}
"#,
r#"if chars.clone().next() == Some('\n')"#,
);
}
#[test]
fn move_guard_to_arm_body_works() {
check_assist(
move_guard_to_arm_body,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' <|>if chars.clone().next() == Some('\n') => false,
_ => true
}
}
"#,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' => if chars.clone().next() == Some('\n') { <|>false },
_ => true
}
}
"#,
);
}
#[test]
fn move_guard_to_arm_body_works_complex_match() {
check_assist(
move_guard_to_arm_body,
r#"
fn f() {
match x {
<|>y @ 4 | y @ 5 if y > 5 => true,
_ => false
}
}
"#,
r#"
fn f() {
match x {
y @ 4 | y @ 5 => if y > 5 { <|>true },
_ => false
}
}
"#,
);
}
#[test]
fn move_arm_cond_to_match_guard_works() {
check_assist(
move_arm_cond_to_match_guard,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' => if chars.clone().next() == Some('\n') { <|>false },
_ => true
}
}
"#,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' <|>if chars.clone().next() == Some('\n') => false,
_ => true
}
}
"#,
);
}
#[test]
fn move_arm_cond_to_match_guard_if_let_not_works() {
check_assist_not_applicable(
move_arm_cond_to_match_guard,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' => if let Some(_) = chars.clone().next() { <|>false },
_ => true
}
}
"#,
);
}
#[test]
fn move_arm_cond_to_match_guard_if_empty_body_works() {
check_assist(
move_arm_cond_to_match_guard,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' => if chars.clone().next().is_some() { <|> },
_ => true
}
}
"#,
r#"
fn f() {
let t = 'a';
let chars = "abcd";
match t {
'\r' <|>if chars.clone().next().is_some() => { },
_ => true
}
}
"#,
);
}
#[test]
fn move_arm_cond_to_match_guard_if_multiline_body_works() {
check_assist(
move_arm_cond_to_match_guard,
r#"
fn f() {
let mut t = 'a';
let chars = "abcd";
match t {
'\r' => if chars.clone().next().is_some() {
t = 'e';<|>
false
},
_ => true
}
}
"#,
r#"
fn f() {
let mut t = 'a';
let chars = "abcd";
match t {
'\r' <|>if chars.clone().next().is_some() => {
t = 'e';
false
},
_ => true
}
}
"#,
);
}
}
|
