From fc34403018079ea053f26d0a31b7517053c7dd8c Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 13 Aug 2020 17:33:38 +0200 Subject: Rename ra_assists -> assists --- crates/assists/src/handlers/generate_function.rs | 1058 ++++++++++++++++++++++ 1 file changed, 1058 insertions(+) create mode 100644 crates/assists/src/handlers/generate_function.rs (limited to 'crates/assists/src/handlers/generate_function.rs') diff --git a/crates/assists/src/handlers/generate_function.rs b/crates/assists/src/handlers/generate_function.rs new file mode 100644 index 000000000..b38d64058 --- /dev/null +++ b/crates/assists/src/handlers/generate_function.rs @@ -0,0 +1,1058 @@ +use base_db::FileId; +use hir::HirDisplay; +use rustc_hash::{FxHashMap, FxHashSet}; +use syntax::{ + ast::{ + self, + edit::{AstNodeEdit, IndentLevel}, + make, ArgListOwner, AstNode, ModuleItemOwner, + }, + SyntaxKind, SyntaxNode, TextSize, +}; + +use crate::{ + assist_config::SnippetCap, + utils::{render_snippet, Cursor}, + AssistContext, AssistId, AssistKind, Assists, +}; + +// Assist: generate_function +// +// Adds a stub function with a signature matching the function under the cursor. +// +// ``` +// struct Baz; +// fn baz() -> Baz { Baz } +// fn foo() { +// bar<|>("", baz()); +// } +// +// ``` +// -> +// ``` +// struct Baz; +// fn baz() -> Baz { Baz } +// fn foo() { +// bar("", baz()); +// } +// +// fn bar(arg: &str, baz: Baz) { +// ${0:todo!()} +// } +// +// ``` +pub(crate) fn generate_function(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)?; + let path = path_expr.path()?; + + if ctx.sema.resolve_path(&path).is_some() { + // The function call already resolves, no need to add a function + return None; + } + + let target_module = match path.qualifier() { + Some(qualifier) => match ctx.sema.resolve_path(&qualifier) { + Some(hir::PathResolution::Def(hir::ModuleDef::Module(module))) => Some(module), + _ => return None, + }, + None => None, + }; + + let function_builder = FunctionBuilder::from_call(&ctx, &call, &path, target_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 new_fn = function_template.to_string(ctx.config.snippet_cap); + 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), + } + }, + ) +} + +struct FunctionTemplate { + insert_offset: TextSize, + placeholder_expr: ast::MacroCall, + leading_ws: String, + fn_def: ast::Fn, + trailing_ws: String, + file: FileId, +} + +impl FunctionTemplate { + fn to_string(&self, cap: Option) -> String { + let f = match cap { + Some(cap) => render_snippet( + cap, + self.fn_def.syntax(), + Cursor::Replace(self.placeholder_expr.syntax()), + ), + None => self.fn_def.to_string(), + }; + format!("{}{}{}", self.leading_ws, f, self.trailing_ws) + } +} + +struct FunctionBuilder { + target: GeneratedFunctionTarget, + fn_name: ast::Name, + type_params: Option, + params: ast::ParamList, + file: FileId, + needs_pub: bool, +} + +impl FunctionBuilder { + /// Prepares a generated function that matches `call`. + /// The function is generated in `target_module` or next to `call` + fn from_call( + ctx: &AssistContext, + call: &ast::CallExpr, + path: &ast::Path, + target_module: Option, + ) -> Option { + let mut file = ctx.frange.file_id; + let target = match &target_module { + Some(target_module) => { + let module_source = target_module.definition_source(ctx.db()); + let (in_file, target) = next_space_for_fn_in_module(ctx.sema.db, &module_source)?; + file = in_file; + target + } + None => next_space_for_fn_after_call_site(&call)?, + }; + 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)?; + + Some(Self { target, fn_name, type_params, params, file, needs_pub }) + } + + fn render(self) -> FunctionTemplate { + let placeholder_expr = make::expr_todo(); + let fn_body = make::block_expr(vec![], Some(placeholder_expr)); + let visibility = if self.needs_pub { Some(make::visibility_pub_crate()) } else { None }; + let mut fn_def = + make::fn_(visibility, self.fn_name, self.type_params, self.params, fn_body); + let leading_ws; + let trailing_ws; + + let insert_offset = match self.target { + GeneratedFunctionTarget::BehindItem(it) => { + let indent = IndentLevel::from_node(&it); + leading_ws = format!("\n\n{}", indent); + fn_def = fn_def.indent(indent); + trailing_ws = String::new(); + it.text_range().end() + } + GeneratedFunctionTarget::InEmptyItemList(it) => { + let indent = IndentLevel::from_node(it.syntax()); + leading_ws = format!("\n{}", indent + 1); + fn_def = fn_def.indent(indent + 1); + trailing_ws = format!("\n{}", indent); + it.syntax().text_range().start() + TextSize::of('{') + } + }; + + let placeholder_expr = + fn_def.syntax().descendants().find_map(ast::MacroCall::cast).unwrap(); + FunctionTemplate { + insert_offset, + placeholder_expr, + leading_ws, + fn_def, + trailing_ws, + file: self.file, + } + } +} + +enum GeneratedFunctionTarget { + BehindItem(SyntaxNode), + InEmptyItemList(ast::ItemList), +} + +impl GeneratedFunctionTarget { + fn syntax(&self) -> &SyntaxNode { + match self { + GeneratedFunctionTarget::BehindItem(it) => it, + GeneratedFunctionTarget::InEmptyItemList(it) => it.syntax(), + } + } +} + +fn fn_name(call: &ast::Path) -> Option { + let name = call.segment()?.syntax().to_string(); + Some(make::name(&name)) +} + +/// Computes the type variables and arguments required for the generated function +fn fn_args( + ctx: &AssistContext, + target_module: hir::Module, + call: &ast::CallExpr, +) -> Option<(Option, ast::ParamList)> { + let mut arg_names = Vec::new(); + let mut arg_types = Vec::new(); + for arg in call.arg_list()?.args() { + arg_names.push(match fn_arg_name(&arg) { + Some(name) => name, + None => String::from("arg"), + }); + arg_types.push(match fn_arg_type(ctx, target_module, &arg) { + Some(ty) => ty, + None => String::from("()"), + }); + } + deduplicate_arg_names(&mut arg_names); + let params = arg_names.into_iter().zip(arg_types).map(|(name, ty)| make::param(name, ty)); + Some((None, make::param_list(params))) +} + +/// Makes duplicate argument names unique by appending incrementing numbers. +/// +/// ``` +/// let mut names: Vec = +/// vec!["foo".into(), "foo".into(), "bar".into(), "baz".into(), "bar".into()]; +/// deduplicate_arg_names(&mut names); +/// let expected: Vec = +/// vec!["foo_1".into(), "foo_2".into(), "bar_1".into(), "baz".into(), "bar_2".into()]; +/// assert_eq!(names, expected); +/// ``` +fn deduplicate_arg_names(arg_names: &mut Vec) { + let arg_name_counts = arg_names.iter().fold(FxHashMap::default(), |mut m, name| { + *m.entry(name).or_insert(0) += 1; + m + }); + let duplicate_arg_names: FxHashSet = arg_name_counts + .into_iter() + .filter(|(_, count)| *count >= 2) + .map(|(name, _)| name.clone()) + .collect(); + + let mut counter_per_name = FxHashMap::default(); + for arg_name in arg_names.iter_mut() { + if duplicate_arg_names.contains(arg_name) { + let counter = counter_per_name.entry(arg_name.clone()).or_insert(1); + arg_name.push('_'); + arg_name.push_str(&counter.to_string()); + *counter += 1; + } + } +} + +fn fn_arg_name(fn_arg: &ast::Expr) -> Option { + match fn_arg { + ast::Expr::CastExpr(cast_expr) => fn_arg_name(&cast_expr.expr()?), + _ => Some( + fn_arg + .syntax() + .descendants() + .filter(|d| ast::NameRef::can_cast(d.kind())) + .last()? + .to_string(), + ), + } +} + +fn fn_arg_type( + ctx: &AssistContext, + target_module: hir::Module, + fn_arg: &ast::Expr, +) -> Option { + let ty = ctx.sema.type_of_expr(fn_arg)?; + if ty.is_unknown() { + return None; + } + + if let Ok(rendered) = ty.display_source_code(ctx.db(), target_module.into()) { + Some(rendered) + } else { + None + } +} + +/// Returns the position inside the current mod or file +/// 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 { + let mut ancestors = expr.syntax().ancestors().peekable(); + let mut last_ancestor: Option = None; + while let Some(next_ancestor) = ancestors.next() { + match next_ancestor.kind() { + SyntaxKind::SOURCE_FILE => { + break; + } + SyntaxKind::ITEM_LIST => { + if ancestors.peek().map(|a| a.kind()) == Some(SyntaxKind::MODULE) { + break; + } + } + _ => {} + } + last_ancestor = Some(next_ancestor); + } + last_ancestor.map(GeneratedFunctionTarget::BehindItem) +} + +fn next_space_for_fn_in_module( + db: &dyn hir::db::AstDatabase, + module_source: &hir::InFile, +) -> Option<(FileId, GeneratedFunctionTarget)> { + let file = module_source.file_id.original_file(db); + let assist_item = match &module_source.value { + hir::ModuleSource::SourceFile(it) => { + if let Some(last_item) = it.items().last() { + GeneratedFunctionTarget::BehindItem(last_item.syntax().clone()) + } else { + GeneratedFunctionTarget::BehindItem(it.syntax().clone()) + } + } + hir::ModuleSource::Module(it) => { + if let Some(last_item) = it.item_list().and_then(|it| it.items().last()) { + GeneratedFunctionTarget::BehindItem(last_item.syntax().clone()) + } else { + GeneratedFunctionTarget::InEmptyItemList(it.item_list()?) + } + } + }; + Some((file, assist_item)) +} + +#[cfg(test)] +mod tests { + use crate::tests::{check_assist, check_assist_not_applicable}; + + use super::*; + + #[test] + fn add_function_with_no_args() { + check_assist( + generate_function, + r" +fn foo() { + bar<|>(); +} +", + r" +fn foo() { + bar(); +} + +fn bar() { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_from_method() { + // This ensures that the function is correctly generated + // in the next outer mod or file + check_assist( + generate_function, + r" +impl Foo { + fn foo() { + bar<|>(); + } +} +", + r" +impl Foo { + fn foo() { + bar(); + } +} + +fn bar() { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_directly_after_current_block() { + // The new fn should not be created at the end of the file or module + check_assist( + generate_function, + r" +fn foo1() { + bar<|>(); +} + +fn foo2() {} +", + r" +fn foo1() { + bar(); +} + +fn bar() { + ${0:todo!()} +} + +fn foo2() {} +", + ) + } + + #[test] + fn add_function_with_no_args_in_same_module() { + check_assist( + generate_function, + r" +mod baz { + fn foo() { + bar<|>(); + } +} +", + r" +mod baz { + fn foo() { + bar(); + } + + fn bar() { + ${0:todo!()} + } +} +", + ) + } + + #[test] + fn add_function_with_function_call_arg() { + check_assist( + generate_function, + r" +struct Baz; +fn baz() -> Baz { todo!() } +fn foo() { + bar<|>(baz()); +} +", + r" +struct Baz; +fn baz() -> Baz { todo!() } +fn foo() { + bar(baz()); +} + +fn bar(baz: Baz) { + ${0:todo!()} +} +", + ); + } + + #[test] + fn add_function_with_method_call_arg() { + check_assist( + generate_function, + r" +struct Baz; +impl Baz { + fn foo(&self) -> Baz { + ba<|>r(self.baz()) + } + fn baz(&self) -> Baz { + Baz + } +} +", + r" +struct Baz; +impl Baz { + fn foo(&self) -> Baz { + bar(self.baz()) + } + fn baz(&self) -> Baz { + Baz + } +} + +fn bar(baz: Baz) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_with_string_literal_arg() { + check_assist( + generate_function, + r#" +fn foo() { + <|>bar("bar") +} +"#, + r#" +fn foo() { + bar("bar") +} + +fn bar(arg: &str) { + ${0:todo!()} +} +"#, + ) + } + + #[test] + fn add_function_with_char_literal_arg() { + check_assist( + generate_function, + r#" +fn foo() { + <|>bar('x') +} +"#, + r#" +fn foo() { + bar('x') +} + +fn bar(arg: char) { + ${0:todo!()} +} +"#, + ) + } + + #[test] + fn add_function_with_int_literal_arg() { + check_assist( + generate_function, + r" +fn foo() { + <|>bar(42) +} +", + r" +fn foo() { + bar(42) +} + +fn bar(arg: i32) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_with_cast_int_literal_arg() { + check_assist( + generate_function, + r" +fn foo() { + <|>bar(42 as u8) +} +", + r" +fn foo() { + bar(42 as u8) +} + +fn bar(arg: u8) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn name_of_cast_variable_is_used() { + // Ensures that the name of the cast type isn't used + // in the generated function signature. + check_assist( + generate_function, + r" +fn foo() { + let x = 42; + bar<|>(x as u8) +} +", + r" +fn foo() { + let x = 42; + bar(x as u8) +} + +fn bar(x: u8) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_with_variable_arg() { + check_assist( + generate_function, + r" +fn foo() { + let worble = (); + <|>bar(worble) +} +", + r" +fn foo() { + let worble = (); + bar(worble) +} + +fn bar(worble: ()) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_with_impl_trait_arg() { + check_assist( + generate_function, + r" +trait Foo {} +fn foo() -> impl Foo { + todo!() +} +fn baz() { + <|>bar(foo()) +} +", + r" +trait Foo {} +fn foo() -> impl Foo { + todo!() +} +fn baz() { + bar(foo()) +} + +fn bar(foo: impl Foo) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn borrowed_arg() { + check_assist( + generate_function, + r" +struct Baz; +fn baz() -> Baz { todo!() } + +fn foo() { + bar<|>(&baz()) +} +", + r" +struct Baz; +fn baz() -> Baz { todo!() } + +fn foo() { + bar(&baz()) +} + +fn bar(baz: &Baz) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_with_qualified_path_arg() { + check_assist( + generate_function, + r" +mod Baz { + pub struct Bof; + pub fn baz() -> Bof { Bof } +} +fn foo() { + <|>bar(Baz::baz()) +} +", + r" +mod Baz { + pub struct Bof; + pub fn baz() -> Bof { Bof } +} +fn foo() { + bar(Baz::baz()) +} + +fn bar(baz: Baz::Bof) { + ${0:todo!()} +} +", + ) + } + + #[test] + #[ignore] + // FIXME fix printing the generics of a `Ty` to make this test pass + fn add_function_with_generic_arg() { + check_assist( + generate_function, + r" +fn foo(t: T) { + <|>bar(t) +} +", + r" +fn foo(t: T) { + bar(t) +} + +fn bar(t: T) { + ${0:todo!()} +} +", + ) + } + + #[test] + #[ignore] + // FIXME Fix function type printing to make this test pass + fn add_function_with_fn_arg() { + check_assist( + generate_function, + r" +struct Baz; +impl Baz { + fn new() -> Self { Baz } +} +fn foo() { + <|>bar(Baz::new); +} +", + r" +struct Baz; +impl Baz { + fn new() -> Self { Baz } +} +fn foo() { + bar(Baz::new); +} + +fn bar(arg: fn() -> Baz) { + ${0:todo!()} +} +", + ) + } + + #[test] + #[ignore] + // FIXME Fix closure type printing to make this test pass + fn add_function_with_closure_arg() { + check_assist( + generate_function, + r" +fn foo() { + let closure = |x: i64| x - 1; + <|>bar(closure) +} +", + r" +fn foo() { + let closure = |x: i64| x - 1; + bar(closure) +} + +fn bar(closure: impl Fn(i64) -> i64) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn unresolveable_types_default_to_unit() { + check_assist( + generate_function, + r" +fn foo() { + <|>bar(baz) +} +", + r" +fn foo() { + bar(baz) +} + +fn bar(baz: ()) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn arg_names_dont_overlap() { + check_assist( + generate_function, + r" +struct Baz; +fn baz() -> Baz { Baz } +fn foo() { + <|>bar(baz(), baz()) +} +", + r" +struct Baz; +fn baz() -> Baz { Baz } +fn foo() { + bar(baz(), baz()) +} + +fn bar(baz_1: Baz, baz_2: Baz) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn arg_name_counters_start_at_1_per_name() { + check_assist( + generate_function, + r#" +struct Baz; +fn baz() -> Baz { Baz } +fn foo() { + <|>bar(baz(), baz(), "foo", "bar") +} +"#, + r#" +struct Baz; +fn baz() -> Baz { Baz } +fn foo() { + bar(baz(), baz(), "foo", "bar") +} + +fn bar(baz_1: Baz, baz_2: Baz, arg_1: &str, arg_2: &str) { + ${0:todo!()} +} +"#, + ) + } + + #[test] + fn add_function_in_module() { + check_assist( + generate_function, + r" +mod bar {} + +fn foo() { + bar::my_fn<|>() +} +", + r" +mod bar { + pub(crate) fn my_fn() { + ${0:todo!()} + } +} + +fn foo() { + bar::my_fn() +} +", + ) + } + + #[test] + #[ignore] + // Ignored until local imports are supported. + // See https://github.com/rust-analyzer/rust-analyzer/issues/1165 + fn qualified_path_uses_correct_scope() { + check_assist( + generate_function, + " +mod foo { + pub struct Foo; +} +fn bar() { + use foo::Foo; + let foo = Foo; + baz<|>(foo) +} +", + " +mod foo { + pub struct Foo; +} +fn bar() { + use foo::Foo; + let foo = Foo; + baz(foo) +} + +fn baz(foo: foo::Foo) { + ${0:todo!()} +} +", + ) + } + + #[test] + fn add_function_in_module_containing_other_items() { + check_assist( + generate_function, + r" +mod bar { + fn something_else() {} +} + +fn foo() { + bar::my_fn<|>() +} +", + r" +mod bar { + fn something_else() {} + + pub(crate) fn my_fn() { + ${0:todo!()} + } +} + +fn foo() { + bar::my_fn() +} +", + ) + } + + #[test] + fn add_function_in_nested_module() { + check_assist( + generate_function, + r" +mod bar { + mod baz {} +} + +fn foo() { + bar::baz::my_fn<|>() +} +", + r" +mod bar { + mod baz { + pub(crate) fn my_fn() { + ${0:todo!()} + } + } +} + +fn foo() { + bar::baz::my_fn() +} +", + ) + } + + #[test] + fn add_function_in_another_file() { + check_assist( + generate_function, + r" +//- /main.rs +mod foo; + +fn main() { + foo::bar<|>() +} +//- /foo.rs +", + r" + + +pub(crate) fn bar() { + ${0:todo!()} +}", + ) + } + + #[test] + fn add_function_not_applicable_if_function_already_exists() { + check_assist_not_applicable( + generate_function, + r" +fn foo() { + bar<|>(); +} + +fn bar() {} +", + ) + } + + #[test] + fn add_function_not_applicable_if_unresolved_variable_in_call_is_selected() { + check_assist_not_applicable( + // bar is resolved, but baz isn't. + // The assist is only active if the cursor is on an unresolved path, + // but the assist should only be offered if the path is a function call. + generate_function, + r" +fn foo() { + bar(b<|>az); +} + +fn bar(baz: ()) {} +", + ) + } + + #[test] + #[ignore] + fn create_method_with_no_args() { + check_assist( + generate_function, + r" +struct Foo; +impl Foo { + fn foo(&self) { + self.bar()<|>; + } +} + ", + r" +struct Foo; +impl Foo { + fn foo(&self) { + self.bar(); + } + fn bar(&self) { + todo!(); + } +} + ", + ) + } +} -- cgit v1.2.3