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|
use hir::db::HirDatabase;
use ra_fmt::unwrap_trivial_block;
use ra_syntax::{
ast::{self, make},
AstNode,
};
use crate::{Assist, AssistCtx, AssistId};
use ast::edit::IndentLevel;
// Assist: replace_if_let_with_match
//
// Replaces `if let` with an else branch with a `match` expression.
//
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// <|>if let Action::Move { distance } = action {
// foo(distance)
// } else {
// bar()
// }
// }
// ```
// ->
// ```
// enum Action { Move { distance: u32 }, Stop }
//
// fn handle(action: Action) {
// match action {
// Action::Move { distance } => foo(distance),
// _ => bar(),
// }
// }
// ```
pub(crate) fn replace_if_let_with_match(ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
let if_expr: ast::IfExpr = ctx.find_node_at_offset()?;
let cond = if_expr.condition()?;
let pat = cond.pat()?;
let expr = cond.expr()?;
let then_block = if_expr.then_branch()?;
let else_block = match if_expr.else_branch()? {
ast::ElseBranch::Block(it) => it,
ast::ElseBranch::IfExpr(_) => return None,
};
ctx.add_assist(AssistId("replace_if_let_with_match"), "Replace with match", |edit| {
let match_expr = {
let then_arm = {
let then_expr = unwrap_trivial_block(then_block);
make::match_arm(vec![pat], then_expr)
};
let else_arm = {
let else_expr = unwrap_trivial_block(else_block);
make::match_arm(vec![make::placeholder_pat().into()], else_expr)
};
make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]))
};
let match_expr = IndentLevel::from_node(if_expr.syntax()).increase_indent(match_expr);
edit.target(if_expr.syntax().text_range());
edit.set_cursor(if_expr.syntax().text_range().start());
edit.replace_ast::<ast::Expr>(if_expr.into(), match_expr.into());
})
}
#[cfg(test)]
mod tests {
use super::*;
use crate::helpers::{check_assist, check_assist_target};
#[test]
fn test_replace_if_let_with_match_unwraps_simple_expressions() {
check_assist(
replace_if_let_with_match,
"
impl VariantData {
pub fn is_struct(&self) -> bool {
if <|>let VariantData::Struct(..) = *self {
true
} else {
false
}
}
} ",
"
impl VariantData {
pub fn is_struct(&self) -> bool {
<|>match *self {
VariantData::Struct(..) => true,
_ => false,
}
}
} ",
)
}
#[test]
fn test_replace_if_let_with_match_doesnt_unwrap_multiline_expressions() {
check_assist(
replace_if_let_with_match,
"
fn foo() {
if <|>let VariantData::Struct(..) = a {
bar(
123
)
} else {
false
}
} ",
"
fn foo() {
<|>match a {
VariantData::Struct(..) => {
bar(
123
)
}
_ => false,
}
} ",
)
}
#[test]
fn replace_if_let_with_match_target() {
check_assist_target(
replace_if_let_with_match,
"
impl VariantData {
pub fn is_struct(&self) -> bool {
if <|>let VariantData::Struct(..) = *self {
true
} else {
false
}
}
} ",
"if let VariantData::Struct(..) = *self {
true
} else {
false
}",
);
}
}
|
