diff --git a/crates/ide_assists/src/handlers/generate_function.rs b/crates/ide_assists/src/handlers/generate_function.rs index 255f9ae4ec21..cb281d5dcb3a 100644 --- a/crates/ide_assists/src/handlers/generate_function.rs +++ b/crates/ide_assists/src/handlers/generate_function.rs @@ -1,4 +1,4 @@ -use hir::{HirDisplay, TypeInfo}; +use hir::{HasSource, HirDisplay, InFile, Module, TypeInfo}; use ide_db::{base_db::FileId, helpers::SnippetCap}; use rustc_hash::{FxHashMap, FxHashSet}; use stdx::to_lower_snake_case; @@ -13,7 +13,7 @@ use crate::{ utils::useless_type_special_case, - utils::{render_snippet, Cursor}, + utils::{find_struct_impl, render_snippet, Cursor}, AssistContext, AssistId, AssistKind, Assists, }; @@ -43,6 +43,31 @@ // // ``` pub(crate) fn generate_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { + gen_fn(acc, ctx).or_else(|| gen_method(acc, ctx)) +} + +enum FuncExpr { + Func(ast::CallExpr), + Method(ast::MethodCallExpr), +} + +impl FuncExpr { + fn arg_list(&self) -> Option { + match self { + FuncExpr::Func(fn_call) => fn_call.arg_list(), + FuncExpr::Method(m_call) => m_call.arg_list(), + } + } + + fn syntax(&self) -> &SyntaxNode { + match self { + FuncExpr::Func(fn_call) => fn_call.syntax(), + FuncExpr::Method(m_call) => m_call.syntax(), + } + } +} + +fn gen_fn(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { let path_expr: ast::PathExpr = ctx.find_node_at_offset()?; let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?; @@ -79,6 +104,69 @@ pub(crate) fn generate_function(acc: &mut Assists, ctx: &AssistContext) -> Optio ) } +fn gen_method(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { + let call: ast::MethodCallExpr = ctx.find_node_at_offset()?; + let fn_name: ast::NameRef = ast::NameRef::cast( + call.syntax().children().find(|child| child.kind() == SyntaxKind::NAME_REF)?, + )?; + let ty = ctx.sema.type_of_expr(&call.receiver()?)?.original().strip_references().as_adt()?; + + let current_module = + ctx.sema.scope(ctx.find_node_at_offset::()?.syntax()).module()?; + let target_module = ty.module(ctx.sema.db); + + if current_module.krate() != target_module.krate() { + return None; + } + + let (impl_, file) = match ty { + hir::Adt::Struct(strukt) => get_impl(strukt.source(ctx.sema.db)?.syntax(), &fn_name, ctx), + hir::Adt::Enum(en) => get_impl(en.source(ctx.sema.db)?.syntax(), &fn_name, ctx), + hir::Adt::Union(union) => get_impl(union.source(ctx.sema.db)?.syntax(), &fn_name, ctx), + }?; + + let function_builder = FunctionBuilder::from_method_call( + ctx, + &call, + &fn_name, + &impl_, + file, + target_module, + current_module, + )?; + let target = call.syntax().text_range(); + + acc.add( + AssistId("generate_function", AssistKind::Generate), + format!("Generate `{}` function", function_builder.fn_name), + target, + |builder| { + let function_template = function_builder.render(); + builder.edit_file(function_template.file); + let mut new_fn = function_template.to_string(ctx.config.snippet_cap); + if impl_.is_none() { + new_fn = format!("\nimpl {} {{\n{}\n}}", ty.name(ctx.sema.db), new_fn,); + } + match ctx.config.snippet_cap { + Some(cap) => builder.insert_snippet(cap, function_template.insert_offset, new_fn), + None => builder.insert(function_template.insert_offset, new_fn), + } + }, + ) +} + +fn get_impl( + adt: InFile<&SyntaxNode>, + fn_name: &ast::NameRef, + ctx: &AssistContext, +) -> Option<(Option, FileId)> { + let file = adt.file_id.original_file(ctx.sema.db); + let adt = adt.value; + let adt = ast::Adt::cast(adt.clone())?; + let r = find_struct_impl(ctx, &adt, fn_name.text().as_str())?; + Some((r, file)) +} + struct FunctionTemplate { insert_offset: TextSize, leading_ws: String, @@ -130,12 +218,12 @@ fn from_call( file = in_file; target } - None => next_space_for_fn_after_call_site(call)?, + None => next_space_for_fn_after_call_site(FuncExpr::Func(call.clone()))?, }; let needs_pub = target_module.is_some(); let target_module = target_module.or_else(|| ctx.sema.scope(target.syntax()).module())?; let fn_name = fn_name(path)?; - let (type_params, params) = fn_args(ctx, target_module, call)?; + let (type_params, params) = fn_args(ctx, target_module, FuncExpr::Func(call.clone()))?; let await_expr = call.syntax().parent().and_then(ast::AwaitExpr::cast); let is_async = await_expr.is_some(); @@ -181,6 +269,79 @@ fn from_call( }) } + fn from_method_call( + ctx: &AssistContext, + call: &ast::MethodCallExpr, + name: &ast::NameRef, + impl_: &Option, + file: FileId, + target_module: Module, + current_module: Module, + ) -> Option { + // let mut file = ctx.frange.file_id; + // let target_module = ctx.sema.scope(call.syntax()).module()?; + let target = match impl_ { + Some(impl_) => next_space_for_fn_in_impl(&impl_)?, + None => { + next_space_for_fn_in_module( + ctx.sema.db, + &target_module.definition_source(ctx.sema.db), + )? + .1 + } + }; + let needs_pub = !module_is_descendant(¤t_module, &target_module, ctx); + + let fn_name = make::name(&name.text()); + let (type_params, params) = fn_args(ctx, target_module, FuncExpr::Method(call.clone()))?; + + let await_expr = call.syntax().parent().and_then(ast::AwaitExpr::cast); + let is_async = await_expr.is_some(); + + // should_render_snippet intends to express a rough level of confidence about + // the correctness of the return type. + // + // If we are able to infer some return type, and that return type is not unit, we + // don't want to render the snippet. The assumption here is in this situation the + // return type is just as likely to be correct as any other part of the generated + // function. + // + // In the case where the return type is inferred as unit it is likely that the + // user does in fact intend for this generated function to return some non unit + // type, but that the current state of their code doesn't allow that return type + // to be accurately inferred. + let (ret_ty, should_render_snippet) = { + match ctx + .sema + .type_of_expr(&ast::Expr::MethodCallExpr(call.clone())) + .map(TypeInfo::original) + { + Some(ty) if ty.is_unknown() || ty.is_unit() => (make::ty_unit(), true), + Some(ty) => { + let rendered = ty.display_source_code(ctx.db(), target_module.into()); + match rendered { + Ok(rendered) => (make::ty(&rendered), false), + Err(_) => (make::ty_unit(), true), + } + } + None => (make::ty_unit(), true), + } + }; + let ret_type = make::ret_type(ret_ty); + + Some(Self { + target, + fn_name, + type_params, + params, + ret_type, + should_render_snippet, + file, + needs_pub, + is_async, + }) + } + fn render(self) -> FunctionTemplate { let placeholder_expr = make::ext::expr_todo(); let fn_body = make::block_expr(vec![], Some(placeholder_expr)); @@ -249,7 +410,7 @@ fn fn_name(call: &ast::Path) -> Option { fn fn_args( ctx: &AssistContext, target_module: hir::Module, - call: &ast::CallExpr, + call: FuncExpr, ) -> Option<(Option, ast::ParamList)> { let mut arg_names = Vec::new(); let mut arg_types = Vec::new(); @@ -277,7 +438,17 @@ fn fn_args( let params = arg_names.into_iter().zip(arg_types).map(|(name, ty)| { make::param(make::ext::simple_ident_pat(make::name(&name)).into(), make::ty(&ty)) }); - Some((None, make::param_list(None, params))) + + Some(( + None, + make::param_list( + match call { + FuncExpr::Func(_) => None, + FuncExpr::Method(_) => Some(make::self_param()), + }, + params, + ), + )) } /// Makes duplicate argument names unique by appending incrementing numbers. @@ -348,7 +519,7 @@ fn fn_arg_type( /// directly after the current block /// We want to write the generated function directly after /// fns, impls or macro calls, but inside mods -fn next_space_for_fn_after_call_site(expr: &ast::CallExpr) -> Option { +fn next_space_for_fn_after_call_site(expr: FuncExpr) -> Option { let mut ancestors = expr.syntax().ancestors().peekable(); let mut last_ancestor: Option = None; while let Some(next_ancestor) = ancestors.next() { @@ -401,6 +572,26 @@ fn next_space_for_fn_in_module( Some((file, assist_item)) } +fn next_space_for_fn_in_impl(impl_: &ast::Impl) -> Option { + if let Some(last_item) = impl_.assoc_item_list().and_then(|it| it.assoc_items().last()) { + Some(GeneratedFunctionTarget::BehindItem(last_item.syntax().clone())) + } else { + Some(GeneratedFunctionTarget::InEmptyItemList(impl_.assoc_item_list()?.syntax().clone())) + } +} + +fn module_is_descendant(module: &hir::Module, ans: &hir::Module, ctx: &AssistContext) -> bool { + if module == ans { + return true; + } + for c in ans.children(ctx.sema.db) { + if module_is_descendant(module, &c, ctx) { + return true; + } + } + false +} + #[cfg(test)] mod tests { use crate::tests::{check_assist, check_assist_not_applicable}; @@ -1164,8 +1355,7 @@ fn bar(baz: ()) {} #[test] fn create_method_with_no_args() { - // FIXME: This is wrong, this should just work. - check_assist_not_applicable( + check_assist( generate_function, r#" struct Foo; @@ -1174,7 +1364,19 @@ fn foo(&self) { self.bar()$0; } } - "#, +"#, + r#" +struct Foo; +impl Foo { + fn foo(&self) { + self.bar(); + } + + fn bar(&self) ${0:-> ()} { + todo!() + } +} +"#, ) } @@ -1195,6 +1397,131 @@ fn foo() { async fn bar(arg: i32) ${0:-> ()} { todo!() } +", + ) + } + + #[test] + fn create_method() { + check_assist( + generate_function, + r" +struct S; +fn foo() {S.bar$0();} +", + r" +struct S; +fn foo() {S.bar();} +impl S { + + +fn bar(&self) ${0:-> ()} { + todo!() +} +} +", + ) + } + + #[test] + fn create_method_within_an_impl() { + check_assist( + generate_function, + r" +struct S; +fn foo() {S.bar$0();} +impl S {} + +", + r" +struct S; +fn foo() {S.bar();} +impl S { + fn bar(&self) ${0:-> ()} { + todo!() + } +} + +", + ) + } + + #[test] + fn create_method_from_different_module() { + check_assist( + generate_function, + r" +mod s { + pub struct S; +} +fn foo() {s::S.bar$0();} +", + r" +mod s { + pub struct S; +impl S { + + + pub(crate) fn bar(&self) ${0:-> ()} { + todo!() + } +} +} +fn foo() {s::S.bar();} +", + ) + } + + #[test] + fn create_method_from_descendant_module() { + check_assist( + generate_function, + r" +struct S; +mod s { + fn foo() { + super::S.bar$0(); + } +} + +", + r" +struct S; +mod s { + fn foo() { + super::S.bar(); + } +} +impl S { + + +fn bar(&self) ${0:-> ()} { + todo!() +} +} + +", + ) + } + + #[test] + fn create_method_with_cursor_anywhere_on_call_expresion() { + check_assist( + generate_function, + r" +struct S; +fn foo() {$0S.bar();} +", + r" +struct S; +fn foo() {S.bar();} +impl S { + + +fn bar(&self) ${0:-> ()} { + todo!() +} +} ", ) } diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs index 87faac0aa324..ec90be35a6ee 100644 --- a/crates/syntax/src/ast/make.rs +++ b/crates/syntax/src/ast/make.rs @@ -531,6 +531,10 @@ pub fn param(pat: ast::Pat, ty: ast::Type) -> ast::Param { ast_from_text(&format!("fn f({}: {}) {{ }}", pat, ty)) } +pub fn self_param() -> ast::SelfParam { + ast_from_text(&format!("fn f(&self) {{ }}")) +} + pub fn ret_type(ty: ast::Type) -> ast::RetType { ast_from_text(&format!("fn f() -> {} {{ }}", ty)) }