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|
use std::iter;
use ra_syntax::{
ast::{self, edit::IndentLevel, make},
AstNode,
};
use crate::{utils::TryEnum, Assist, AssistCtx, AssistId};
// Assist: replace_unwrap_with_match
//
// Replaces `unwrap` a `match` expression. Works for Result and Option.
//
// ```
// enum Result<T, E> { Ok(T), Err(E) }
// fn main() {
// let x: Result<i32, i32> = Result::Ok(92);
// let y = x.<|>unwrap();
// }
// ```
// ->
// ```
// enum Result<T, E> { Ok(T), Err(E) }
// fn main() {
// let x: Result<i32, i32> = Result::Ok(92);
// let y = match x {
// Ok(a) => a,
// _ => unreachable!(),
// };
// }
// ```
pub(crate) fn replace_unwrap_with_match(ctx: AssistCtx) -> Option<Assist> {
let method_call: ast::MethodCallExpr = ctx.find_node_at_offset()?;
let name = method_call.name_ref()?;
if name.text() != "unwrap" {
return None;
}
let caller = method_call.expr()?;
let ty = ctx.sema.type_of_expr(&caller)?;
let happy_variant = TryEnum::from_ty(ctx.sema, &ty)?.happy_case();
ctx.add_assist(AssistId("replace_unwrap_with_match"), "Replace unwrap with match", |edit| {
let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
let it = make::bind_pat(make::name("a")).into();
let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
let unreachable_call = make::unreachable_macro_call().into();
let err_arm = make::match_arm(iter::once(make::placeholder_pat().into()), unreachable_call);
let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
let match_expr = make::expr_match(caller.clone(), match_arm_list);
let match_expr = IndentLevel::from_node(method_call.syntax()).increase_indent(match_expr);
edit.target(method_call.syntax().text_range());
edit.set_cursor(caller.syntax().text_range().start());
edit.replace_ast::<ast::Expr>(method_call.into(), match_expr);
})
}
#[cfg(test)]
mod tests {
use super::*;
use crate::helpers::{check_assist, check_assist_target};
#[test]
fn test_replace_result_unwrap_with_match() {
check_assist(
replace_unwrap_with_match,
r"
enum Result<T, E> { Ok(T), Err(E) }
fn i<T>(a: T) -> T { a }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = i(x).<|>unwrap();
}
",
r"
enum Result<T, E> { Ok(T), Err(E) }
fn i<T>(a: T) -> T { a }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = <|>match i(x) {
Ok(a) => a,
_ => unreachable!(),
};
}
",
)
}
#[test]
fn test_replace_option_unwrap_with_match() {
check_assist(
replace_unwrap_with_match,
r"
enum Option<T> { Some(T), None }
fn i<T>(a: T) -> T { a }
fn main() {
let x = Option::Some(92);
let y = i(x).<|>unwrap();
}
",
r"
enum Option<T> { Some(T), None }
fn i<T>(a: T) -> T { a }
fn main() {
let x = Option::Some(92);
let y = <|>match i(x) {
Some(a) => a,
_ => unreachable!(),
};
}
",
);
}
#[test]
fn test_replace_result_unwrap_with_match_chaining() {
check_assist(
replace_unwrap_with_match,
r"
enum Result<T, E> { Ok(T), Err(E) }
fn i<T>(a: T) -> T { a }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = i(x).<|>unwrap().count_zeroes();
}
",
r"
enum Result<T, E> { Ok(T), Err(E) }
fn i<T>(a: T) -> T { a }
fn main() {
let x: Result<i32, i32> = Result::Ok(92);
let y = <|>match i(x) {
Ok(a) => a,
_ => unreachable!(),
}.count_zeroes();
}
",
)
}
#[test]
fn replace_unwrap_with_match_target() {
check_assist_target(
replace_unwrap_with_match,
r"
enum Option<T> { Some(T), None }
fn i<T>(a: T) -> T { a }
fn main() {
let x = Option::Some(92);
let y = i(x).<|>unwrap();
}
",
r"i(x).unwrap()",
);
}
}
|
