use hir::{db::HirDatabase, HasSource}; use ra_syntax::{ ast::{self, make, AstNode, NameOwner}, SmolStr, }; use crate::{ast_editor::AstEditor, Assist, AssistCtx, AssistId}; #[derive(PartialEq)] enum AddMissingImplMembersMode { DefaultMethodsOnly, NoDefaultMethods, } pub(crate) fn add_missing_impl_members(ctx: AssistCtx) -> Option { add_missing_impl_members_inner( ctx, AddMissingImplMembersMode::NoDefaultMethods, "add_impl_missing_members", "add missing impl members", ) } pub(crate) fn add_missing_default_members(ctx: AssistCtx) -> Option { add_missing_impl_members_inner( ctx, AddMissingImplMembersMode::DefaultMethodsOnly, "add_impl_default_members", "add impl default members", ) } fn add_missing_impl_members_inner( mut ctx: AssistCtx, mode: AddMissingImplMembersMode, assist_id: &'static str, label: &'static str, ) -> Option { let impl_node = ctx.node_at_offset::()?; let impl_item_list = impl_node.item_list()?; let trait_def = { let file_id = ctx.frange.file_id; let analyzer = hir::SourceAnalyzer::new(ctx.db, file_id, impl_node.syntax(), None); resolve_target_trait_def(ctx.db, &analyzer, &impl_node)? }; let def_name = |item: &ast::ImplItem| -> Option { match item { ast::ImplItem::FnDef(def) => def.name(), ast::ImplItem::TypeAliasDef(def) => def.name(), ast::ImplItem::ConstDef(def) => def.name(), } .map(|it| it.text().clone()) }; let trait_items = trait_def.item_list()?.impl_items(); let impl_items = impl_item_list.impl_items().collect::>(); let missing_items: Vec<_> = trait_items .filter(|t| def_name(t).is_some()) .filter(|t| match t { ast::ImplItem::FnDef(def) => match mode { AddMissingImplMembersMode::DefaultMethodsOnly => def.body().is_some(), AddMissingImplMembersMode::NoDefaultMethods => def.body().is_none(), }, _ => mode == AddMissingImplMembersMode::NoDefaultMethods, }) .filter(|t| impl_items.iter().all(|i| def_name(i) != def_name(t))) .collect(); if missing_items.is_empty() { return None; } ctx.add_action(AssistId(assist_id), label, |edit| { let n_existing_items = impl_item_list.impl_items().count(); let items = missing_items.into_iter().map(|it| match it { ast::ImplItem::FnDef(def) => strip_docstring(add_body(def).into()), _ => strip_docstring(it), }); let mut ast_editor = AstEditor::new(impl_item_list); ast_editor.append_items(items); let first_new_item = ast_editor.ast().impl_items().nth(n_existing_items).unwrap(); let cursor_position = first_new_item.syntax().text_range().start(); ast_editor.into_text_edit(edit.text_edit_builder()); edit.set_cursor(cursor_position); }); ctx.build() } fn strip_docstring(item: ast::ImplItem) -> ast::ImplItem { let mut ast_editor = AstEditor::new(item); ast_editor.strip_attrs_and_docs(); ast_editor.ast().to_owned() } fn add_body(fn_def: ast::FnDef) -> ast::FnDef { if fn_def.body().is_none() { fn_def.with_body(make::block_from_expr(make::expr_unimplemented())) } else { fn_def } } /// Given an `ast::ImplBlock`, resolves the target trait (the one being /// implemented) to a `ast::TraitDef`. fn resolve_target_trait_def( db: &impl HirDatabase, analyzer: &hir::SourceAnalyzer, impl_block: &ast::ImplBlock, ) -> Option { let ast_path = impl_block .target_trait() .map(|it| it.syntax().clone()) .and_then(ast::PathType::cast)? .path()?; match analyzer.resolve_path(db, &ast_path) { Some(hir::PathResolution::Def(hir::ModuleDef::Trait(def))) => Some(def.source(db).ast), _ => None, } } #[cfg(test)] mod tests { use super::*; use crate::helpers::{check_assist, check_assist_not_applicable}; #[test] fn test_add_missing_impl_members() { check_assist( add_missing_impl_members, " 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) {} <|> }", " 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) {} <|>type Output; const CONST: usize = 42; fn foo(&self) { unimplemented!() } fn baz(&self) { unimplemented!() } }", ); } #[test] fn test_copied_overriden_members() { check_assist( add_missing_impl_members, " trait Foo { fn foo(&self); fn bar(&self) -> bool { true } fn baz(&self) -> u32 { 42 } } struct S; impl Foo for S { fn bar(&self) {} <|> }", " 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) { unimplemented!() } }", ); } #[test] fn test_empty_impl_block() { check_assist( add_missing_impl_members, " trait Foo { fn foo(&self); } struct S; impl Foo for S { <|> }", " trait Foo { fn foo(&self); } struct S; impl Foo for S { <|>fn foo(&self) { unimplemented!() } }", ); } #[test] fn test_cursor_after_empty_impl_block() { check_assist( add_missing_impl_members, " trait Foo { fn foo(&self); } struct S; impl Foo for S {}<|>", " trait Foo { fn foo(&self); } struct S; impl Foo for S { <|>fn foo(&self) { unimplemented!() } }", ) } #[test] fn test_empty_trait() { check_assist_not_applicable( add_missing_impl_members, " 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, " 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 { <|>type Output; fn foo(&self) { unimplemented!() } }"#, ) } #[test] fn test_default_methods() { check_assist( add_missing_default_members, " 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 { <|> }", " 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 { <|>fn valid(some: u32) -> bool { false } }", ) } }