use either::Either; use hir::{known, Callable, HasVisibility, HirDisplay, Semantics}; use ide_db::helpers::FamousDefs; use ide_db::RootDatabase; use stdx::to_lower_snake_case; use syntax::{ ast::{self, ArgListOwner, AstNode, NameOwner}, match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T, }; use crate::FileId; #[derive(Clone, Debug, PartialEq, Eq)] pub struct InlayHintsConfig { pub type_hints: bool, pub parameter_hints: bool, pub chaining_hints: bool, pub max_length: Option, } #[derive(Clone, Debug, PartialEq, Eq)] pub enum InlayKind { TypeHint, ParameterHint, ChainingHint, } #[derive(Debug)] pub struct InlayHint { pub range: TextRange, pub kind: InlayKind, pub label: SmolStr, } // Feature: Inlay Hints // // rust-analyzer shows additional information inline with the source code. // Editors usually render this using read-only virtual text snippets interspersed with code. // // rust-analyzer shows hints for // // * types of local variables // * names of function arguments // * types of chained expressions // // **Note:** VS Code does not have native support for inlay hints https://github.com/microsoft/vscode/issues/16221[yet] and the hints are implemented using decorations. // This approach has limitations, the caret movement and bracket highlighting near the edges of the hint may be weird: // https://github.com/rust-analyzer/rust-analyzer/issues/1623[1], https://github.com/rust-analyzer/rust-analyzer/issues/3453[2]. // // |=== // | Editor | Action Name // // | VS Code | **Rust Analyzer: Toggle inlay hints* // |=== // // image::https://user-images.githubusercontent.com/48062697/113020660-b5f98b80-917a-11eb-8d70-3be3fd558cdd.png[] pub(crate) fn inlay_hints( db: &RootDatabase, file_id: FileId, config: &InlayHintsConfig, ) -> Vec { let _p = profile::span("inlay_hints"); let sema = Semantics::new(db); let file = sema.parse(file_id); let mut res = Vec::new(); for node in file.syntax().descendants() { if let Some(expr) = ast::Expr::cast(node.clone()) { get_chaining_hints(&mut res, &sema, config, expr); } match_ast! { match node { ast::CallExpr(it) => { get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it)); }, ast::MethodCallExpr(it) => { get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it)); }, ast::IdentPat(it) => { get_bind_pat_hints(&mut res, &sema, config, it); }, _ => (), } } } res } fn get_chaining_hints( acc: &mut Vec, sema: &Semantics, config: &InlayHintsConfig, expr: ast::Expr, ) -> Option<()> { if !config.chaining_hints { return None; } if matches!(expr, ast::Expr::RecordExpr(_)) { return None; } let krate = sema.scope(expr.syntax()).module().map(|it| it.krate()); let famous_defs = FamousDefs(sema, krate); let mut tokens = expr .syntax() .siblings_with_tokens(Direction::Next) .filter_map(NodeOrToken::into_token) .filter(|t| match t.kind() { SyntaxKind::WHITESPACE if !t.text().contains('\n') => false, SyntaxKind::COMMENT => false, _ => true, }); // Chaining can be defined as an expression whose next sibling tokens are newline and dot // Ignoring extra whitespace and comments let next = tokens.next()?.kind(); if next == SyntaxKind::WHITESPACE { let mut next_next = tokens.next()?.kind(); while next_next == SyntaxKind::WHITESPACE { next_next = tokens.next()?.kind(); } if next_next == T![.] { let ty = sema.type_of_expr(&expr)?; if ty.is_unknown() { return None; } if matches!(expr, ast::Expr::PathExpr(_)) { if let Some(hir::Adt::Struct(st)) = ty.as_adt() { if st.fields(sema.db).is_empty() { return None; } } } acc.push(InlayHint { range: expr.syntax().text_range(), kind: InlayKind::ChainingHint, label: hint_iterator(sema, &famous_defs, config, &ty).unwrap_or_else(|| { ty.display_truncated(sema.db, config.max_length).to_string().into() }), }); } } Some(()) } fn get_param_name_hints( acc: &mut Vec, sema: &Semantics, config: &InlayHintsConfig, expr: ast::Expr, ) -> Option<()> { if !config.parameter_hints { return None; } let (callable, arg_list) = get_callable(sema, &expr)?; let hints = callable .params(sema.db) .into_iter() .zip(arg_list.args()) .filter_map(|((param, _ty), arg)| { let param_name = match param? { Either::Left(_) => "self".to_string(), Either::Right(pat) => match pat { ast::Pat::IdentPat(it) => it.name()?.to_string(), _ => return None, }, }; Some((param_name, arg)) }) .filter(|(param_name, arg)| !should_hide_param_name_hint(sema, &callable, param_name, arg)) .map(|(param_name, arg)| InlayHint { range: arg.syntax().text_range(), kind: InlayKind::ParameterHint, label: param_name.into(), }); acc.extend(hints); Some(()) } fn get_bind_pat_hints( acc: &mut Vec, sema: &Semantics, config: &InlayHintsConfig, pat: ast::IdentPat, ) -> Option<()> { if !config.type_hints { return None; } let krate = sema.scope(pat.syntax()).module().map(|it| it.krate()); let famous_defs = FamousDefs(sema, krate); let ty = sema.type_of_pat(&pat.clone().into())?; if should_not_display_type_hint(sema, &pat, &ty) { return None; } acc.push(InlayHint { range: pat.syntax().text_range(), kind: InlayKind::TypeHint, label: hint_iterator(sema, &famous_defs, config, &ty) .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string().into()), }); Some(()) } /// Checks if the type is an Iterator from std::iter and replaces its hint with an `impl Iterator`. fn hint_iterator( sema: &Semantics, famous_defs: &FamousDefs, config: &InlayHintsConfig, ty: &hir::Type, ) -> Option { let db = sema.db; let strukt = ty.strip_references().as_adt()?; let krate = strukt.module(db).krate(); if krate != famous_defs.core()? { return None; } let iter_trait = famous_defs.core_iter_Iterator()?; let iter_mod = famous_defs.core_iter()?; // Assert that this struct comes from `core::iter`. if !(strukt.visibility(db) == hir::Visibility::Public && strukt.module(db).path_to_root(db).contains(&iter_mod)) { return None; } if ty.impls_trait(db, iter_trait, &[]) { let assoc_type_item = iter_trait.items(db).into_iter().find_map(|item| match item { hir::AssocItem::TypeAlias(alias) if alias.name(db) == known::Item => Some(alias), _ => None, })?; if let Some(ty) = ty.normalize_trait_assoc_type(db, &[], assoc_type_item) { const LABEL_START: &str = "impl Iterator bool { if let Some(hir::Adt::Enum(enum_data)) = pat_ty.as_adt() { let pat_text = bind_pat.to_string(); enum_data .variants(db) .into_iter() .map(|variant| variant.name(db).to_string()) .any(|enum_name| enum_name == pat_text) } else { false } } fn should_not_display_type_hint( sema: &Semantics, bind_pat: &ast::IdentPat, pat_ty: &hir::Type, ) -> bool { let db = sema.db; if pat_ty.is_unknown() { return true; } if let Some(hir::Adt::Struct(s)) = pat_ty.as_adt() { if s.fields(db).is_empty() && s.name(db).to_string() == bind_pat.to_string() { return true; } } for node in bind_pat.syntax().ancestors() { match_ast! { match node { ast::LetStmt(it) => return it.ty().is_some(), ast::Param(it) => return it.ty().is_some(), ast::MatchArm(_it) => return pat_is_enum_variant(db, bind_pat, pat_ty), ast::IfExpr(it) => { return it.condition().and_then(|condition| condition.pat()).is_some() && pat_is_enum_variant(db, bind_pat, pat_ty); }, ast::WhileExpr(it) => { return it.condition().and_then(|condition| condition.pat()).is_some() && pat_is_enum_variant(db, bind_pat, pat_ty); }, ast::ForExpr(it) => { // We *should* display hint only if user provided "in {expr}" and we know the type of expr (and it's not unit). // Type of expr should be iterable. return it.in_token().is_none() || it.iterable() .and_then(|iterable_expr| sema.type_of_expr(&iterable_expr)) .map_or(true, |iterable_ty| iterable_ty.is_unknown() || iterable_ty.is_unit()) }, _ => (), } } } false } fn should_hide_param_name_hint( sema: &Semantics, callable: &hir::Callable, param_name: &str, argument: &ast::Expr, ) -> bool { // These are to be tested in the `parameter_hint_heuristics` test // hide when: // - the parameter name is a suffix of the function's name // - the argument is an enum whose name is equal to the parameter // - exact argument<->parameter match(ignoring leading underscore) or parameter is a prefix/suffix // of argument with _ splitting it off // - param starts with `ra_fixture` // - param is a well known name in an unary function let param_name = param_name.trim_start_matches('_'); if param_name.is_empty() { return true; } let fn_name = match callable.kind() { hir::CallableKind::Function(it) => Some(it.name(sema.db).to_string()), _ => None, }; let fn_name = fn_name.as_deref(); is_param_name_suffix_of_fn_name(param_name, callable, fn_name) || is_enum_name_similar_to_param_name(sema, argument, param_name) || is_argument_similar_to_param_name(argument, param_name) || param_name.starts_with("ra_fixture") || (callable.n_params() == 1 && is_obvious_param(param_name)) } fn is_argument_similar_to_param_name(argument: &ast::Expr, param_name: &str) -> bool { // check whether param_name and argument are the same or // whether param_name is a prefix/suffix of argument(split at `_`) let argument = match get_string_representation(argument) { Some(argument) => argument, None => return false, }; let param_name = param_name.trim_start_matches('_'); let argument = argument.trim_start_matches('_'); if argument.strip_prefix(param_name).map_or(false, |s| s.starts_with('_')) { return true; } if argument.strip_suffix(param_name).map_or(false, |s| s.ends_with('_')) { return true; } argument == param_name } /// Hide the parameter name of an unary function if it is a `_` - prefixed suffix of the function's name, or equal. /// /// `fn strip_suffix(suffix)` will be hidden. /// `fn stripsuffix(suffix)` will not be hidden. fn is_param_name_suffix_of_fn_name( param_name: &str, callable: &Callable, fn_name: Option<&str>, ) -> bool { match (callable.n_params(), fn_name) { (1, Some(function)) => { function == param_name || (function.len() > param_name.len() && function.ends_with(param_name) && function[..function.len() - param_name.len()].ends_with('_')) } _ => false, } } fn is_enum_name_similar_to_param_name( sema: &Semantics, argument: &ast::Expr, param_name: &str, ) -> bool { match sema.type_of_expr(argument).and_then(|t| t.as_adt()) { Some(hir::Adt::Enum(e)) => to_lower_snake_case(&e.name(sema.db).to_string()) == param_name, _ => false, } } fn get_string_representation(expr: &ast::Expr) -> Option { match expr { ast::Expr::MethodCallExpr(method_call_expr) => { let name_ref = method_call_expr.name_ref()?; match name_ref.text().as_str() { "clone" | "as_ref" => method_call_expr.receiver().map(|rec| rec.to_string()), name_ref => Some(name_ref.to_owned()), } } ast::Expr::FieldExpr(field_expr) => Some(field_expr.name_ref()?.to_string()), ast::Expr::PathExpr(path_expr) => Some(path_expr.path()?.segment()?.to_string()), ast::Expr::PrefixExpr(prefix_expr) => get_string_representation(&prefix_expr.expr()?), ast::Expr::RefExpr(ref_expr) => get_string_representation(&ref_expr.expr()?), _ => None, } } fn is_obvious_param(param_name: &str) -> bool { // avoid displaying hints for common functions like map, filter, etc. // or other obvious words used in std let is_obvious_param_name = matches!(param_name, "predicate" | "value" | "pat" | "rhs" | "other"); param_name.len() == 1 || is_obvious_param_name } fn get_callable( sema: &Semantics, expr: &ast::Expr, ) -> Option<(hir::Callable, ast::ArgList)> { match expr { ast::Expr::CallExpr(expr) => { sema.type_of_expr(&expr.expr()?)?.as_callable(sema.db).zip(expr.arg_list()) } ast::Expr::MethodCallExpr(expr) => { sema.resolve_method_call_as_callable(expr).zip(expr.arg_list()) } _ => None, } } #[cfg(test)] mod tests { use expect_test::{expect, Expect}; use test_utils::extract_annotations; use crate::{fixture, inlay_hints::InlayHintsConfig}; const TEST_CONFIG: InlayHintsConfig = InlayHintsConfig { type_hints: true, parameter_hints: true, chaining_hints: true, max_length: None, }; fn check(ra_fixture: &str) { check_with_config(TEST_CONFIG, ra_fixture); } fn check_params(ra_fixture: &str) { check_with_config( InlayHintsConfig { parameter_hints: true, type_hints: false, chaining_hints: false, max_length: None, }, ra_fixture, ); } fn check_types(ra_fixture: &str) { check_with_config( InlayHintsConfig { parameter_hints: false, type_hints: true, chaining_hints: false, max_length: None, }, ra_fixture, ); } fn check_chains(ra_fixture: &str) { check_with_config( InlayHintsConfig { parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None, }, ra_fixture, ); } fn check_with_config(config: InlayHintsConfig, ra_fixture: &str) { let (analysis, file_id) = fixture::file(&ra_fixture); let expected = extract_annotations(&*analysis.file_text(file_id).unwrap()); let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap(); let actual = inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::>(); assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual); } fn check_expect(config: InlayHintsConfig, ra_fixture: &str, expect: Expect) { let (analysis, file_id) = fixture::file(&ra_fixture); let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap(); expect.assert_debug_eq(&inlay_hints) } #[test] fn hints_disabled() { check_with_config( InlayHintsConfig { type_hints: false, parameter_hints: false, chaining_hints: false, max_length: None, }, r#" fn foo(a: i32, b: i32) -> i32 { a + b } fn main() { let _x = foo(4, 4); }"#, ); } // Parameter hint tests #[test] fn param_hints_only() { check_params( r#" fn foo(a: i32, b: i32) -> i32 { a + b } fn main() { let _x = foo( 4, //^ a 4, //^ b ); }"#, ); } #[test] fn param_name_similar_to_fn_name_still_hints() { check_params( r#" fn max(x: i32, y: i32) -> i32 { x + y } fn main() { let _x = max( 4, //^ x 4, //^ y ); }"#, ); } #[test] fn param_name_similar_to_fn_name() { check_params( r#" fn param_with_underscore(with_underscore: i32) -> i32 { with_underscore } fn main() { let _x = param_with_underscore( 4, ); }"#, ); check_params( r#" fn param_with_underscore(underscore: i32) -> i32 { underscore } fn main() { let _x = param_with_underscore( 4, ); }"#, ); } #[test] fn param_name_same_as_fn_name() { check_params( r#" fn foo(foo: i32) -> i32 { foo } fn main() { let _x = foo( 4, ); }"#, ); } #[test] fn never_hide_param_when_multiple_params() { check_params( r#" fn foo(foo: i32, bar: i32) -> i32 { bar + baz } fn main() { let _x = foo( 4, //^ foo 8, //^ bar ); }"#, ); } #[test] fn param_hints_look_through_as_ref_and_clone() { check_params( r#" fn foo(bar: i32, baz: f32) {} fn main() { let bar = 3; let baz = &"baz"; let fez = 1.0; foo(bar.clone(), bar.clone()); //^^^^^^^^^^^ baz foo(bar.as_ref(), bar.as_ref()); //^^^^^^^^^^^^ baz } "#, ); } #[test] fn self_param_hints() { check_params( r#" struct Foo; impl Foo { fn foo(self: Self) {} fn bar(self: &Self) {} } fn main() { Foo::foo(Foo); //^^^ self Foo::bar(&Foo); //^^^^ self } "#, ) } #[test] fn param_name_hints_show_for_literals() { check_params( r#"pub fn test(a: i32, b: i32) -> [i32; 2] { [a, b] } fn main() { test( 0xa_b, //^^^^^ a 0xa_b, //^^^^^ b ); }"#, ) } #[test] fn function_call_parameter_hint() { check_params( r#" //- minicore: option struct FileId {} struct SmolStr {} struct TextRange {} struct SyntaxKind {} struct NavigationTarget {} struct Test {} impl Test { fn method(&self, mut param: i32) -> i32 { param * 2 } fn from_syntax( file_id: FileId, name: SmolStr, focus_range: Option, full_range: TextRange, kind: SyntaxKind, docs: Option, ) -> NavigationTarget { NavigationTarget {} } } fn test_func(mut foo: i32, bar: i32, msg: &str, _: i32, last: i32) -> i32 { foo + bar } fn main() { let not_literal = 1; let _: i32 = test_func(1, 2, "hello", 3, not_literal); //^ foo ^ bar ^^^^^^^ msg ^^^^^^^^^^^ last let t: Test = Test {}; t.method(123); //^^^ param Test::method(&t, 3456); //^^ self ^^^^ param Test::from_syntax( FileId {}, //^^^^^^^^^ file_id "impl".into(), //^^^^^^^^^^^^^ name None, //^^^^ focus_range TextRange {}, //^^^^^^^^^^^^ full_range SyntaxKind {}, //^^^^^^^^^^^^^ kind None, //^^^^ docs ); }"#, ); } #[test] fn parameter_hint_heuristics() { check_params( r#" fn check(ra_fixture_thing: &str) {} fn map(f: i32) {} fn filter(predicate: i32) {} fn strip_suffix(suffix: &str) {} fn stripsuffix(suffix: &str) {} fn same(same: u32) {} fn same2(_same2: u32) {} fn enum_matches_param_name(completion_kind: CompletionKind) {} fn foo(param: u32) {} fn bar(param_eter: u32) {} enum CompletionKind { Keyword, } fn non_ident_pat((a, b): (u32, u32)) {} fn main() { check(""); map(0); filter(0); strip_suffix(""); stripsuffix(""); //^^ suffix same(0); same2(0); enum_matches_param_name(CompletionKind::Keyword); let param = 0; foo(param); let param_end = 0; foo(param_end); let start_param = 0; foo(start_param); let param2 = 0; foo(param2); //^^^^^^ param let param_eter = 0; bar(param_eter); let param_eter_end = 0; bar(param_eter_end); let start_param_eter = 0; bar(start_param_eter); let param_eter2 = 0; bar(param_eter2); //^^^^^^^^^^^ param_eter non_ident_pat((0, 0)); }"#, ); } // Type-Hint tests #[test] fn type_hints_only() { check_types( r#" fn foo(a: i32, b: i32) -> i32 { a + b } fn main() { let _x = foo(4, 4); //^^ i32 }"#, ); } #[test] fn default_generic_types_should_not_be_displayed() { check( r#" struct Test { k: K, t: T } fn main() { let zz = Test { t: 23u8, k: 33 }; //^^ Test let zz_ref = &zz; //^^^^^^ &Test let test = || zz; //^^^^ || -> Test }"#, ); } #[test] fn shorten_iterators_in_associated_params() { check_types( r#" //- minicore: iterators use core::iter; pub struct SomeIter {} impl SomeIter { pub fn new() -> Self { SomeIter {} } pub fn push(&mut self, t: T) {} } impl Iterator for SomeIter { type Item = T; fn next(&mut self) -> Option { None } } fn main() { let mut some_iter = SomeIter::new(); //^^^^^^^^^^^^^ SomeIter>> some_iter.push(iter::repeat(2).take(2)); let iter_of_iters = some_iter.take(2); //^^^^^^^^^^^^^ impl Iterator> } "#, ); } #[test] fn infer_call_method_return_associated_types_with_generic() { check_types( r#" pub trait Default { fn default() -> Self; } pub trait Foo { type Bar: Default; } pub fn quux() -> T::Bar { let y = Default::default(); //^ ::Bar y } "#, ); } #[test] fn fn_hints() { check_types( r#" //- minicore: fn, sized fn foo() -> impl Fn() { loop {} } fn foo1() -> impl Fn(f64) { loop {} } fn foo2() -> impl Fn(f64, f64) { loop {} } fn foo3() -> impl Fn(f64, f64) -> u32 { loop {} } fn foo4() -> &'static dyn Fn(f64, f64) -> u32 { loop {} } fn foo5() -> &'static dyn Fn(&'static dyn Fn(f64, f64) -> u32, f64) -> u32 { loop {} } fn foo6() -> impl Fn(f64, f64) -> u32 + Sized { loop {} } fn foo7() -> *const (impl Fn(f64, f64) -> u32 + Sized) { loop {} } fn main() { let foo = foo(); // ^^^ impl Fn() let foo = foo1(); // ^^^ impl Fn(f64) let foo = foo2(); // ^^^ impl Fn(f64, f64) let foo = foo3(); // ^^^ impl Fn(f64, f64) -> u32 let foo = foo4(); // ^^^ &dyn Fn(f64, f64) -> u32 let foo = foo5(); // ^^^ &dyn Fn(&dyn Fn(f64, f64) -> u32, f64) -> u32 let foo = foo6(); // ^^^ impl Fn(f64, f64) -> u32 + Sized let foo = foo7(); // ^^^ *const (impl Fn(f64, f64) -> u32 + Sized) } "#, ) } #[test] fn unit_structs_have_no_type_hints() { check_types( r#" //- minicore: result struct SyntheticSyntax; fn main() { match Ok(()) { Ok(_) => (), Err(SyntheticSyntax) => (), } }"#, ); } #[test] fn let_statement() { check_types( r#" #[derive(PartialEq)] enum Option { None, Some(T) } #[derive(PartialEq)] struct Test { a: Option, b: u8 } fn main() { struct InnerStruct {} let test = 54; //^^^^ i32 let test: i32 = 33; let mut test = 33; //^^^^^^^^ i32 let _ = 22; let test = "test"; //^^^^ &str let test = InnerStruct {}; //^^^^ InnerStruct let test = unresolved(); let test = (42, 'a'); //^^^^ (i32, char) let (a, (b, (c,)) = (2, (3, (9.2,)); //^ i32 ^ i32 ^ f64 let &x = &92; //^ i32 }"#, ); } #[test] fn if_expr() { check_types( r#" //- minicore: option struct Test { a: Option, b: u8 } fn main() { let test = Some(Test { a: Some(3), b: 1 }); //^^^^ Option if let None = &test {}; if let test = &test {}; //^^^^ &Option if let Some(test) = &test {}; //^^^^ &Test if let Some(Test { a, b }) = &test {}; //^ &Option ^ &u8 if let Some(Test { a: x, b: y }) = &test {}; //^ &Option ^ &u8 if let Some(Test { a: Some(x), b: y }) = &test {}; //^ &u32 ^ &u8 if let Some(Test { a: None, b: y }) = &test {}; //^ &u8 if let Some(Test { b: y, .. }) = &test {}; //^ &u8 if test == None {} }"#, ); } #[test] fn while_expr() { check_types( r#" //- minicore: option struct Test { a: Option, b: u8 } fn main() { let test = Some(Test { a: Some(3), b: 1 }); //^^^^ Option while let Some(Test { a: Some(x), b: y }) = &test {}; //^ &u32 ^ &u8 }"#, ); } #[test] fn match_arm_list() { check_types( r#" //- minicore: option struct Test { a: Option, b: u8 } fn main() { match Some(Test { a: Some(3), b: 1 }) { None => (), test => (), //^^^^ Option Some(Test { a: Some(x), b: y }) => (), //^ u32 ^ u8 _ => {} } }"#, ); } #[test] fn incomplete_for_no_hint() { check_types( r#" fn main() { let data = &[1i32, 2, 3]; //^^^^ &[i32; 3] for i }"#, ); check( r#" pub struct Vec {} impl Vec { pub fn new() -> Self { Vec {} } pub fn push(&mut self, t: T) {} } impl IntoIterator for Vec { type Item=T; } fn main() { let mut data = Vec::new(); //^^^^^^^^ Vec<&str> data.push("foo"); for i in println!("Unit expr"); } "#, ); } #[test] fn complete_for_hint() { check_types( r#" //- minicore: iterator pub struct Vec {} impl Vec { pub fn new() -> Self { Vec {} } pub fn push(&mut self, t: T) {} } impl IntoIterator for Vec { type Item=T; } fn main() { let mut data = Vec::new(); //^^^^^^^^ Vec<&str> data.push("foo"); for i in data { //^ &str let z = i; //^ &str } } "#, ); } #[test] fn multi_dyn_trait_bounds() { check_types( r#" pub struct Vec {} impl Vec { pub fn new() -> Self { Vec {} } } pub struct Box {} trait Display {} trait Sync {} fn main() { let _v = Vec::>::new(); //^^ Vec> let _v = Vec::>::new(); //^^ Vec> let _v = Vec::>::new(); //^^ Vec> } "#, ); } #[test] fn shorten_iterator_hints() { check_types( r#" //- minicore: iterators use core::iter; struct MyIter; impl Iterator for MyIter { type Item = (); fn next(&mut self) -> Option { None } } fn main() { let _x = MyIter; //^^ MyIter let _x = iter::repeat(0); //^^ impl Iterator fn generic(t: T) { let _x = iter::repeat(t); //^^ impl Iterator let _chained = iter::repeat(t).take(10); //^^^^^^^^ impl Iterator } } "#, ); } #[test] fn closures() { check( r#" fn main() { let mut start = 0; //^^^^^^^^^ i32 (0..2).for_each(|increment| { start += increment; }); //^^^^^^^^^ i32 let multiply = //^^^^^^^^ |…| -> i32 | a, b| a * b //^ i32 ^ i32 ; let _: i32 = multiply(1, 2); let multiply_ref = &multiply; //^^^^^^^^^^^^ &|…| -> i32 let return_42 = || 42; //^^^^^^^^^ || -> i32 }"#, ); } #[test] fn hint_truncation() { check_with_config( InlayHintsConfig { max_length: Some(8), ..TEST_CONFIG }, r#" struct Smol(T); struct VeryLongOuterName(T); fn main() { let a = Smol(0u32); //^ Smol let b = VeryLongOuterName(0usize); //^ VeryLongOuterName<…> let c = Smol(Smol(0u32)) //^ Smol> }"#, ); } // Chaining hint tests #[test] fn chaining_hints_ignore_comments() { check_expect( InlayHintsConfig { parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None, }, r#" struct A(B); impl A { fn into_b(self) -> B { self.0 } } struct B(C); impl B { fn into_c(self) -> C { self.0 } } struct C; fn main() { let c = A(B(C)) .into_b() // This is a comment // This is another comment .into_c(); } "#, expect![[r#" [ InlayHint { range: 147..172, kind: ChainingHint, label: "B", }, InlayHint { range: 147..154, kind: ChainingHint, label: "A", }, ] "#]], ); } #[test] fn chaining_hints_without_newlines() { check_chains( r#" struct A(B); impl A { fn into_b(self) -> B { self.0 } } struct B(C); impl B { fn into_c(self) -> C { self.0 } } struct C; fn main() { let c = A(B(C)).into_b().into_c(); }"#, ); } #[test] fn struct_access_chaining_hints() { check_expect( InlayHintsConfig { parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None, }, r#" struct A { pub b: B } struct B { pub c: C } struct C(pub bool); struct D; impl D { fn foo(&self) -> i32 { 42 } } fn main() { let x = A { b: B { c: C(true) } } .b .c .0; let x = D .foo(); }"#, expect![[r#" [ InlayHint { range: 143..190, kind: ChainingHint, label: "C", }, InlayHint { range: 143..179, kind: ChainingHint, label: "B", }, ] "#]], ); } #[test] fn generic_chaining_hints() { check_expect( InlayHintsConfig { parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None, }, r#" struct A(T); struct B(T); struct C(T); struct X(T, R); impl A { fn new(t: T) -> Self { A(t) } fn into_b(self) -> B { B(self.0) } } impl B { fn into_c(self) -> C { C(self.0) } } fn main() { let c = A::new(X(42, true)) .into_b() .into_c(); } "#, expect![[r#" [ InlayHint { range: 246..283, kind: ChainingHint, label: "B>", }, InlayHint { range: 246..265, kind: ChainingHint, label: "A>", }, ] "#]], ); } #[test] fn shorten_iterator_chaining_hints() { check_expect( InlayHintsConfig { parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None, }, r#" //- minicore: iterators use core::iter; struct MyIter; impl Iterator for MyIter { type Item = (); fn next(&mut self) -> Option { None } } fn main() { let _x = MyIter.by_ref() .take(5) .by_ref() .take(5) .by_ref(); } "#, expect![[r#" [ InlayHint { range: 174..241, kind: ChainingHint, label: "impl Iterator", }, InlayHint { range: 174..224, kind: ChainingHint, label: "impl Iterator", }, InlayHint { range: 174..206, kind: ChainingHint, label: "impl Iterator", }, InlayHint { range: 174..189, kind: ChainingHint, label: "&mut MyIter", }, ] "#]], ); } }