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|
use std::iter;
use syntax::{
ast::{
self,
edit::{AstNodeEdit, IndentLevel},
make,
},
AstNode,
};
use crate::{
utils::{render_snippet, Cursor, TryEnum},
AssistContext, AssistId, AssistKind, Assists,
};
// 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,
// $0_ => unreachable!(),
// };
// }
// ```
pub(crate) fn replace_unwrap_with_match(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
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();
let target = method_call.syntax().text_range();
acc.add(
AssistId("replace_unwrap_with_match", AssistKind::RefactorRewrite),
"Replace unwrap with match",
target,
|builder| {
let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
let it = make::ident_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::expr_unreachable();
let err_arm =
make::match_arm(iter::once(make::wildcard_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)
.indent(IndentLevel::from_node(method_call.syntax()));
let range = method_call.syntax().text_range();
match ctx.config.snippet_cap {
Some(cap) => {
let err_arm = match_expr
.syntax()
.descendants()
.filter_map(ast::MatchArm::cast)
.last()
.unwrap();
let snippet =
render_snippet(cap, match_expr.syntax(), Cursor::Before(err_arm.syntax()));
builder.replace_snippet(cap, range, snippet)
}
None => builder.replace(range, match_expr.to_string()),
}
},
)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_assist, check_assist_target};
use super::*;
#[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,
$0_ => 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,
$0_ => 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,
$0_ => 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()",
);
}
}
|
