Auto merge of #15832 - Young-Flash:generate_mut_trait, r=lnicola

feat: add generate_mut_trait_impl assist

![generate_mut_trait_impl](https://github.com/rust-lang/rust-analyzer/assets/71162630/362a5a93-e109-4ffc-996e-9b6e4f54fcfa)

Generate proper `index_mut` method body refer to `index` method body may impossible due to the unpredicable case (#15581).

Here just leave the `index_mut` method body be same as `index` method body, user can modify it manually to meet their need.
This commit is contained in:
bors 2023-11-05 14:00:24 +00:00
commit c1c9e10f72
5 changed files with 248 additions and 0 deletions

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@ -0,0 +1,202 @@
use ide_db::famous_defs::FamousDefs;
use syntax::{
ast::{self, make},
ted, AstNode,
};
use crate::{AssistContext, AssistId, AssistKind, Assists};
// FIXME: Generate proper `index_mut` method body refer to `index` method body may impossible due to the unpredicable case [#15581].
// Here just leave the `index_mut` method body be same as `index` method body, user can modify it manually to meet their need.
// Assist: generate_mut_trait_impl
//
// Adds a IndexMut impl from the `Index` trait.
//
// ```
// # //- minicore: index
// pub enum Axis { X = 0, Y = 1, Z = 2 }
//
// impl<T> core::ops::Index$0<Axis> for [T; 3] {
// type Output = T;
//
// fn index(&self, index: Axis) -> &Self::Output {
// &self[index as usize]
// }
// }
// ```
// ->
// ```
// pub enum Axis { X = 0, Y = 1, Z = 2 }
//
// $0impl<T> core::ops::IndexMut<Axis> for [T; 3] {
// fn index_mut(&mut self, index: Axis) -> &mut Self::Output {
// &self[index as usize]
// }
// }
//
// impl<T> core::ops::Index<Axis> for [T; 3] {
// type Output = T;
//
// fn index(&self, index: Axis) -> &Self::Output {
// &self[index as usize]
// }
// }
// ```
pub(crate) fn generate_mut_trait_impl(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
let impl_def = ctx.find_node_at_offset::<ast::Impl>()?.clone_for_update();
let trait_ = impl_def.trait_()?;
if let ast::Type::PathType(trait_path) = trait_.clone() {
let trait_type = ctx.sema.resolve_trait(&trait_path.path()?)?;
let scope = ctx.sema.scope(trait_path.syntax())?;
if trait_type != FamousDefs(&ctx.sema, scope.krate()).core_convert_Index()? {
return None;
}
}
// Index -> IndexMut
let index_trait = impl_def
.syntax()
.descendants()
.filter_map(ast::NameRef::cast)
.find(|it| it.text() == "Index")?;
ted::replace(
index_trait.syntax(),
make::path_segment(make::name_ref("IndexMut")).clone_for_update().syntax(),
);
// index -> index_mut
let trait_method_name = impl_def
.syntax()
.descendants()
.filter_map(ast::Name::cast)
.find(|it| it.text() == "index")?;
ted::replace(trait_method_name.syntax(), make::name("index_mut").clone_for_update().syntax());
let type_alias = impl_def.syntax().descendants().find_map(ast::TypeAlias::cast)?;
ted::remove(type_alias.syntax());
// &self -> &mut self
let mut_self_param = make::mut_self_param();
let self_param: ast::SelfParam =
impl_def.syntax().descendants().find_map(ast::SelfParam::cast)?;
ted::replace(self_param.syntax(), mut_self_param.clone_for_update().syntax());
// &Self::Output -> &mut Self::Output
let ret_type = impl_def.syntax().descendants().find_map(ast::RetType::cast)?;
ted::replace(
ret_type.syntax(),
make::ret_type(make::ty("&mut Self::Output")).clone_for_update().syntax(),
);
let fn_ = impl_def.assoc_item_list()?.assoc_items().find_map(|it| match it {
ast::AssocItem::Fn(f) => Some(f),
_ => None,
})?;
let assoc_list = make::assoc_item_list().clone_for_update();
assoc_list.add_item(syntax::ast::AssocItem::Fn(fn_));
ted::replace(impl_def.assoc_item_list()?.syntax(), assoc_list.syntax());
let target = impl_def.syntax().text_range();
acc.add(
AssistId("generate_mut_trait_impl", AssistKind::Generate),
"Generate `IndexMut` impl from this `Index` trait",
target,
|edit| {
edit.insert(target.start(), format!("$0{}\n\n", impl_def.to_string()));
},
)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_assist, check_assist_not_applicable};
use super::*;
#[test]
fn test_generate_mut_trait_impl() {
check_assist(
generate_mut_trait_impl,
r#"
//- minicore: index
pub enum Axis { X = 0, Y = 1, Z = 2 }
impl<T> core::ops::Index$0<Axis> for [T; 3] {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
&self[index as usize]
}
}
"#,
r#"
pub enum Axis { X = 0, Y = 1, Z = 2 }
$0impl<T> core::ops::IndexMut<Axis> for [T; 3] {
fn index_mut(&mut self, index: Axis) -> &mut Self::Output {
&self[index as usize]
}
}
impl<T> core::ops::Index<Axis> for [T; 3] {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
&self[index as usize]
}
}
"#,
);
check_assist(
generate_mut_trait_impl,
r#"
//- minicore: index
pub enum Axis { X = 0, Y = 1, Z = 2 }
impl<T> core::ops::Index$0<Axis> for [T; 3] where T: Copy {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
let var_name = &self[index as usize];
var_name
}
}
"#,
r#"
pub enum Axis { X = 0, Y = 1, Z = 2 }
$0impl<T> core::ops::IndexMut<Axis> for [T; 3] where T: Copy {
fn index_mut(&mut self, index: Axis) -> &mut Self::Output {
let var_name = &self[index as usize];
var_name
}
}
impl<T> core::ops::Index<Axis> for [T; 3] where T: Copy {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
let var_name = &self[index as usize];
var_name
}
}
"#,
);
}
#[test]
fn test_generate_mut_trait_impl_not_applicable() {
check_assist_not_applicable(
generate_mut_trait_impl,
r#"
pub trait Index<Idx: ?Sized> {}
impl<T> Index$0<i32> for [T; 3] {}
"#,
);
}
}

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@ -160,6 +160,7 @@ mod handlers {
mod generate_getter_or_setter;
mod generate_impl;
mod generate_is_empty_from_len;
mod generate_mut_trait_impl;
mod generate_new;
mod generate_delegate_methods;
mod generate_trait_from_impl;
@ -274,6 +275,7 @@ pub(crate) fn all() -> &'static [Handler] {
generate_function::generate_function,
generate_impl::generate_impl,
generate_impl::generate_trait_impl,
generate_mut_trait_impl::generate_mut_trait_impl,
generate_is_empty_from_len::generate_is_empty_from_len,
generate_new::generate_new,
generate_trait_from_impl::generate_trait_from_impl,

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@ -1538,6 +1538,42 @@ pub fn is_empty(&self) -> bool {
)
}
#[test]
fn doctest_generate_mut_trait_impl() {
check_doc_test(
"generate_mut_trait_impl",
r#####"
//- minicore: index
pub enum Axis { X = 0, Y = 1, Z = 2 }
impl<T> core::ops::Index$0<Axis> for [T; 3] {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
&self[index as usize]
}
}
"#####,
r#####"
pub enum Axis { X = 0, Y = 1, Z = 2 }
$0impl<T> core::ops::IndexMut<Axis> for [T; 3] {
fn index_mut(&mut self, index: Axis) -> &mut Self::Output {
&self[index as usize]
}
}
impl<T> core::ops::Index<Axis> for [T; 3] {
type Output = T;
fn index(&self, index: Axis) -> &Self::Output {
&self[index as usize]
}
}
"#####,
)
}
#[test]
fn doctest_generate_new() {
check_doc_test(

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@ -54,6 +54,10 @@ pub fn core_convert_Into(&self) -> Option<Trait> {
self.find_trait("core:convert:Into")
}
pub fn core_convert_Index(&self) -> Option<Trait> {
self.find_trait("core:ops:Index")
}
pub fn core_option_Option(&self) -> Option<Enum> {
self.find_enum("core:option:Option")
}

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@ -852,6 +852,10 @@ pub fn self_param() -> ast::SelfParam {
ast_from_text("fn f(&self) { }")
}
pub fn mut_self_param() -> ast::SelfParam {
ast_from_text("fn f(&mut self) { }")
}
pub fn ret_type(ty: ast::Type) -> ast::RetType {
ast_from_text(&format!("fn f() -> {ty} {{ }}"))
}