use hir::HasSource; use syntax::{ ast::{ self, edit::{self, AstNodeEdit, IndentLevel}, make, AstNode, NameOwner, }, SmolStr, }; use crate::{ assist_context::{AssistContext, Assists}, ast_transform::{self, AstTransform, QualifyPaths, SubstituteTypeParams}, utils::{get_missing_assoc_items, render_snippet, resolve_target_trait, Cursor}, AssistId, AssistKind, }; #[derive(PartialEq)] enum AddMissingImplMembersMode { DefaultMethodsOnly, NoDefaultMethods, } // Assist: add_impl_missing_members // // Adds scaffold for required impl members. // // ``` // trait Trait { // Type X; // fn foo(&self) -> T; // fn bar(&self) {} // } // // impl Trait for () {<|> // // } // ``` // -> // ``` // trait Trait { // Type X; // fn foo(&self) -> T; // fn bar(&self) {} // } // // impl Trait for () { // fn foo(&self) -> u32 { // ${0:todo!()} // } // } // ``` pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { add_missing_impl_members_inner( acc, ctx, AddMissingImplMembersMode::NoDefaultMethods, "add_impl_missing_members", "Implement missing members", ) } // Assist: add_impl_default_members // // Adds scaffold for overriding default impl members. // // ``` // trait Trait { // Type X; // fn foo(&self); // fn bar(&self) {} // } // // impl Trait for () { // Type X = (); // fn foo(&self) {}<|> // // } // ``` // -> // ``` // trait Trait { // Type X; // fn foo(&self); // fn bar(&self) {} // } // // impl Trait for () { // Type X = (); // fn foo(&self) {} // // $0fn bar(&self) {} // } // ``` pub(crate) fn add_missing_default_members(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { add_missing_impl_members_inner( acc, ctx, AddMissingImplMembersMode::DefaultMethodsOnly, "add_impl_default_members", "Implement default members", ) } fn add_missing_impl_members_inner( acc: &mut Assists, ctx: &AssistContext, mode: AddMissingImplMembersMode, assist_id: &'static str, label: &'static str, ) -> Option<()> { let _p = profile::span("add_missing_impl_members_inner"); let impl_def = ctx.find_node_at_offset::()?; let trait_ = resolve_target_trait(&ctx.sema, &impl_def)?; let def_name = |item: &ast::AssocItem| -> Option { match item { ast::AssocItem::Fn(def) => def.name(), ast::AssocItem::TypeAlias(def) => def.name(), ast::AssocItem::Const(def) => def.name(), ast::AssocItem::MacroCall(_) => None, } .map(|it| it.text().clone()) }; let missing_items = get_missing_assoc_items(&ctx.sema, &impl_def) .iter() .map(|i| match i { hir::AssocItem::Function(i) => ast::AssocItem::Fn(i.source(ctx.db()).value), hir::AssocItem::TypeAlias(i) => ast::AssocItem::TypeAlias(i.source(ctx.db()).value), hir::AssocItem::Const(i) => ast::AssocItem::Const(i.source(ctx.db()).value), }) .filter(|t| def_name(&t).is_some()) .filter(|t| match t { ast::AssocItem::Fn(def) => match mode { AddMissingImplMembersMode::DefaultMethodsOnly => def.body().is_some(), AddMissingImplMembersMode::NoDefaultMethods => def.body().is_none(), }, _ => mode == AddMissingImplMembersMode::NoDefaultMethods, }) .collect::>(); if missing_items.is_empty() { return None; } let target = impl_def.syntax().text_range(); acc.add(AssistId(assist_id, AssistKind::QuickFix), label, target, |builder| { let impl_item_list = impl_def.assoc_item_list().unwrap_or(make::assoc_item_list()); let n_existing_items = impl_item_list.assoc_items().count(); let source_scope = ctx.sema.scope_for_def(trait_); let target_scope = ctx.sema.scope(impl_def.syntax()); let ast_transform = QualifyPaths::new(&target_scope, &source_scope) .or(SubstituteTypeParams::for_trait_impl(&source_scope, trait_, impl_def.clone())); let items = missing_items .into_iter() .map(|it| ast_transform::apply(&*ast_transform, it)) .map(|it| match it { ast::AssocItem::Fn(def) => ast::AssocItem::Fn(add_body(def)), ast::AssocItem::TypeAlias(def) => ast::AssocItem::TypeAlias(def.remove_bounds()), _ => it, }) .map(|it| edit::remove_attrs_and_docs(&it)); let new_impl_item_list = impl_item_list.append_items(items); let new_impl_def = impl_def.with_assoc_item_list(new_impl_item_list); let first_new_item = new_impl_def.assoc_item_list().unwrap().assoc_items().nth(n_existing_items).unwrap(); match ctx.config.snippet_cap { None => builder.replace(target, new_impl_def.to_string()), Some(cap) => { let mut cursor = Cursor::Before(first_new_item.syntax()); let placeholder; if let ast::AssocItem::Fn(func) = &first_new_item { if let Some(m) = func.syntax().descendants().find_map(ast::MacroCall::cast) { if m.syntax().text() == "todo!()" { placeholder = m; cursor = Cursor::Replace(placeholder.syntax()); } } } builder.replace_snippet( cap, target, render_snippet(cap, new_impl_def.syntax(), cursor), ) } }; }) } fn add_body(fn_def: ast::Fn) -> ast::Fn { if fn_def.body().is_some() { return fn_def; } let body = make::block_expr(None, Some(make::expr_todo())).indent(IndentLevel(1)); fn_def.with_body(body) } #[cfg(test)] mod tests { use crate::tests::{check_assist, check_assist_not_applicable}; use super::*; #[test] fn test_add_missing_impl_members() { check_assist( add_missing_impl_members, r#" trait Foo { type Output; const CONST: usize = 42; fn foo(&self); fn bar(&self); fn baz(&self); } struct S; impl Foo for S { fn bar(&self) {} <|> }"#, r#" trait Foo { type Output; const CONST: usize = 42; fn foo(&self); fn bar(&self); fn baz(&self); } struct S; impl Foo for S { fn bar(&self) {} $0type Output; const CONST: usize = 42; fn foo(&self) { todo!() } fn baz(&self) { todo!() } }"#, ); } #[test] fn test_copied_overriden_members() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self); fn bar(&self) -> bool { true } fn baz(&self) -> u32 { 42 } } struct S; impl Foo for S { fn bar(&self) {} <|> }"#, r#" trait Foo { fn foo(&self); fn bar(&self) -> bool { true } fn baz(&self) -> u32 { 42 } } struct S; impl Foo for S { fn bar(&self) {} fn foo(&self) { ${0:todo!()} } }"#, ); } #[test] fn test_empty_impl_def() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S { <|> }"#, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S { fn foo(&self) { ${0:todo!()} } }"#, ); } #[test] fn test_impl_def_without_braces() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S<|>"#, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S { fn foo(&self) { ${0:todo!()} } }"#, ); } #[test] fn fill_in_type_params_1() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self, t: T) -> &T; } struct S; impl Foo for S { <|> }"#, r#" trait Foo { fn foo(&self, t: T) -> &T; } struct S; impl Foo for S { fn foo(&self, t: u32) -> &u32 { ${0:todo!()} } }"#, ); } #[test] fn fill_in_type_params_2() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self, t: T) -> &T; } struct S; impl Foo for S { <|> }"#, r#" trait Foo { fn foo(&self, t: T) -> &T; } struct S; impl Foo for S { fn foo(&self, t: U) -> &U { ${0:todo!()} } }"#, ); } #[test] fn test_cursor_after_empty_impl_def() { check_assist( add_missing_impl_members, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S {}<|>"#, r#" trait Foo { fn foo(&self); } struct S; impl Foo for S { fn foo(&self) { ${0:todo!()} } }"#, ) } #[test] fn test_qualify_path_1() { check_assist( add_missing_impl_members, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { fn foo(&self, bar: foo::Bar) { ${0:todo!()} } }"#, ); } #[test] fn test_qualify_path_generic() { check_assist( add_missing_impl_members, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { fn foo(&self, bar: foo::Bar) { ${0:todo!()} } }"#, ); } #[test] fn test_qualify_path_and_substitute_param() { check_assist( add_missing_impl_members, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub struct Bar; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { fn foo(&self, bar: foo::Bar) { ${0:todo!()} } }"#, ); } #[test] fn test_substitute_param_no_qualify() { // when substituting params, the substituted param should not be qualified! check_assist( add_missing_impl_members, r#" mod foo { trait Foo { fn foo(&self, bar: T); } pub struct Param; } struct Param; struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { trait Foo { fn foo(&self, bar: T); } pub struct Param; } struct Param; struct S; impl foo::Foo for S { fn foo(&self, bar: Param) { ${0:todo!()} } }"#, ); } #[test] fn test_qualify_path_associated_item() { check_assist( add_missing_impl_members, r#" mod foo { pub struct Bar; impl Bar { type Assoc = u32; } trait Foo { fn foo(&self, bar: Bar::Assoc); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub struct Bar; impl Bar { type Assoc = u32; } trait Foo { fn foo(&self, bar: Bar::Assoc); } } struct S; impl foo::Foo for S { fn foo(&self, bar: foo::Bar::Assoc) { ${0:todo!()} } }"#, ); } #[test] fn test_qualify_path_nested() { check_assist( add_missing_impl_members, r#" mod foo { pub struct Bar; pub struct Baz; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub struct Bar; pub struct Baz; trait Foo { fn foo(&self, bar: Bar); } } struct S; impl foo::Foo for S { fn foo(&self, bar: foo::Bar) { ${0:todo!()} } }"#, ); } #[test] fn test_qualify_path_fn_trait_notation() { check_assist( add_missing_impl_members, r#" mod foo { pub trait Fn { type Output; } trait Foo { fn foo(&self, bar: dyn Fn(u32) -> i32); } } struct S; impl foo::Foo for S { <|> }"#, r#" mod foo { pub trait Fn { type Output; } trait Foo { fn foo(&self, bar: dyn Fn(u32) -> i32); } } struct S; impl foo::Foo for S { fn foo(&self, bar: dyn Fn(u32) -> i32) { ${0:todo!()} } }"#, ); } #[test] fn test_empty_trait() { check_assist_not_applicable( add_missing_impl_members, r#" trait Foo; struct S; impl Foo for S { <|> }"#, ) } #[test] fn test_ignore_unnamed_trait_members_and_default_methods() { check_assist_not_applicable( add_missing_impl_members, r#" trait Foo { fn (arg: u32); fn valid(some: u32) -> bool { false } } struct S; impl Foo for S { <|> }"#, ) } #[test] fn test_with_docstring_and_attrs() { check_assist( add_missing_impl_members, r#" #[doc(alias = "test alias")] trait Foo { /// doc string type Output; #[must_use] fn foo(&self); } struct S; impl Foo for S {}<|>"#, r#" #[doc(alias = "test alias")] trait Foo { /// doc string type Output; #[must_use] fn foo(&self); } struct S; impl Foo for S { $0type Output; fn foo(&self) { todo!() } }"#, ) } #[test] fn test_default_methods() { check_assist( add_missing_default_members, r#" trait Foo { type Output; const CONST: usize = 42; fn valid(some: u32) -> bool { false } fn foo(some: u32) -> bool; } struct S; impl Foo for S { <|> }"#, r#" trait Foo { type Output; const CONST: usize = 42; fn valid(some: u32) -> bool { false } fn foo(some: u32) -> bool; } struct S; impl Foo for S { $0fn valid(some: u32) -> bool { false } }"#, ) } #[test] fn test_generic_single_default_parameter() { check_assist( add_missing_impl_members, r#" trait Foo { fn bar(&self, other: &T); } struct S; impl Foo for S { <|> }"#, r#" trait Foo { fn bar(&self, other: &T); } struct S; impl Foo for S { fn bar(&self, other: &Self) { ${0:todo!()} } }"#, ) } #[test] fn test_generic_default_parameter_is_second() { check_assist( add_missing_impl_members, r#" trait Foo { fn bar(&self, this: &T1, that: &T2); } struct S; impl Foo for S { <|> }"#, r#" trait Foo { fn bar(&self, this: &T1, that: &T2); } struct S; impl Foo for S { fn bar(&self, this: &T, that: &Self) { ${0:todo!()} } }"#, ) } #[test] fn test_assoc_type_bounds_are_removed() { check_assist( add_missing_impl_members, r#" trait Tr { type Ty: Copy + 'static; } impl Tr for ()<|> { }"#, r#" trait Tr { type Ty: Copy + 'static; } impl Tr for () { $0type Ty; }"#, ) } #[test] fn test_whitespace_fixup_preserves_bad_tokens() { check_assist( add_missing_impl_members, r#" trait Tr { fn foo(); } impl Tr for ()<|> { +++ }"#, r#" trait Tr { fn foo(); } impl Tr for () { fn foo() { ${0:todo!()} } +++ }"#, ) } #[test] fn test_whitespace_fixup_preserves_comments() { check_assist( add_missing_impl_members, r#" trait Tr { fn foo(); } impl Tr for ()<|> { // very important }"#, r#" trait Tr { fn foo(); } impl Tr for () { fn foo() { ${0:todo!()} } // very important }"#, ) } }