From f136e1634a8d834d32deb89273717227eedaf153 Mon Sep 17 00:00:00 2001 From: jonboh Date: Sat, 26 Aug 2023 16:26:09 +0200 Subject: [PATCH] new unnecessary_map_on_constructor lint --- CHANGELOG.md | 1 + clippy_lints/src/declared_lints.rs | 1 + clippy_lints/src/lib.rs | 2 + .../src/unnecessary_map_on_constructor.rs | 93 +++++++++++++++++++ tests/ui/eta.fixed | 3 +- tests/ui/eta.rs | 3 +- tests/ui/eta.stderr | 54 +++++------ tests/ui/manual_map_option.fixed | 1 + tests/ui/manual_map_option.rs | 1 + tests/ui/manual_map_option.stderr | 42 ++++----- tests/ui/option_filter_map.fixed | 2 +- tests/ui/option_filter_map.rs | 2 +- tests/ui/result_map_unit_fn_unfixable.rs | 2 +- tests/ui/unnecessary_map_on_constructor.fixed | 56 +++++++++++ tests/ui/unnecessary_map_on_constructor.rs | 56 +++++++++++ .../ui/unnecessary_map_on_constructor.stderr | 53 +++++++++++ 16 files changed, 319 insertions(+), 53 deletions(-) create mode 100644 clippy_lints/src/unnecessary_map_on_constructor.rs create mode 100644 tests/ui/unnecessary_map_on_constructor.fixed create mode 100644 tests/ui/unnecessary_map_on_constructor.rs create mode 100644 tests/ui/unnecessary_map_on_constructor.stderr diff --git a/CHANGELOG.md b/CHANGELOG.md index a7ae4a0ee2c0..9aca13a6cf64 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -5437,6 +5437,7 @@ Released 2018-09-13 [`unnecessary_join`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_join [`unnecessary_lazy_evaluations`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations [`unnecessary_literal_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap +[`unnecessary_map_on_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_on_constructor [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation [`unnecessary_owned_empty_strings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_owned_empty_strings diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index a4d40df52e7b..ecf44e05920a 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -671,6 +671,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::unnamed_address::FN_ADDRESS_COMPARISONS_INFO, crate::unnamed_address::VTABLE_ADDRESS_COMPARISONS_INFO, crate::unnecessary_box_returns::UNNECESSARY_BOX_RETURNS_INFO, + crate::unnecessary_map_on_constructor::UNNECESSARY_MAP_ON_CONSTRUCTOR_INFO, crate::unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS_INFO, crate::unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS_INFO, crate::unnecessary_struct_initialization::UNNECESSARY_STRUCT_INITIALIZATION_INFO, diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 440940a44780..f5035dcfeeb6 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -329,6 +329,7 @@ mod unit_return_expecting_ord; mod unit_types; mod unnamed_address; mod unnecessary_box_returns; +mod unnecessary_map_on_constructor; mod unnecessary_owned_empty_strings; mod unnecessary_self_imports; mod unnecessary_struct_initialization; @@ -1102,6 +1103,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| Box::::default()); store.register_late_pass(|_| Box::new(implied_bounds_in_impls::ImpliedBoundsInImpls)); store.register_late_pass(|_| Box::new(missing_asserts_for_indexing::MissingAssertsForIndexing)); + store.register_late_pass(|_| Box::new(unnecessary_map_on_constructor::UnnecessaryMapOnConstructor)); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/unnecessary_map_on_constructor.rs b/clippy_lints/src/unnecessary_map_on_constructor.rs new file mode 100644 index 000000000000..5aa057580e9d --- /dev/null +++ b/clippy_lints/src/unnecessary_map_on_constructor.rs @@ -0,0 +1,93 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::source::snippet_with_applicability; +use clippy_utils::ty::get_type_diagnostic_name; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::sym; + +declare_clippy_lint! { + /// ### What it does + /// Suggest removing the use of a may (or map_err) method when an Option or Result is being construted. + /// + /// ### Why is this bad? + /// It introduces unnecessary complexity. In this case the function can be used directly and + /// construct the Option or Result from the output. + /// + /// ### Example + /// ```rust + /// Some(4).map(i32::swap_bytes); + /// ``` + /// Use instead: + /// ```rust + /// Some(i32::swap_bytes(4)); + /// ``` + #[clippy::version = "1.73.0"] + pub UNNECESSARY_MAP_ON_CONSTRUCTOR, + complexity, + "using `map`/`map_err` on `Option` or `Result` constructors" +} +declare_lint_pass!(UnnecessaryMapOnConstructor => [UNNECESSARY_MAP_ON_CONSTRUCTOR]); + +impl<'tcx> LateLintPass<'tcx> for UnnecessaryMapOnConstructor { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx>) { + if expr.span.from_expansion() { + return; + } + if let hir::ExprKind::MethodCall(path, recv, args, ..) = expr.kind + && let Some(sym::Option | sym::Result) = get_type_diagnostic_name(cx, cx.typeck_results().expr_ty(recv)){ + let (constructor_path, constructor_item) = + if let hir::ExprKind::Call(constructor, constructor_args) = recv.kind + && let hir::ExprKind::Path(constructor_path) = constructor.kind + && let Some(arg) = constructor_args.get(0) + { + if constructor.span.from_expansion() || arg.span.from_expansion() { + return; + } + (constructor_path, arg) + } else { + return; + }; + let constructor_symbol = match constructor_path { + hir::QPath::Resolved(_, path) => { + if let Some(path_segment) = path.segments.last() { + path_segment.ident.name + } else { + return; + } + }, + hir::QPath::TypeRelative(_, path) => path.ident.name, + hir::QPath::LangItem(_, _, _) => return, + }; + match constructor_symbol { + sym::Some | sym::Ok if path.ident.name == rustc_span::sym::map => (), + sym::Err if path.ident.name == sym!(map_err) => (), + _ => return, + } + + if let Some(map_arg) = args.get(0) + && let hir::ExprKind::Path(fun) = map_arg.kind + { + if map_arg.span.from_expansion() { + return; + } + let mut applicability = Applicability::MachineApplicable; + let fun_snippet = snippet_with_applicability(cx, fun.span(), "_", &mut applicability); + let constructor_snippet = + snippet_with_applicability(cx, constructor_path.span(), "_", &mut applicability); + let constructor_arg_snippet = + snippet_with_applicability(cx, constructor_item.span, "_", &mut applicability); + span_lint_and_sugg( + cx, + UNNECESSARY_MAP_ON_CONSTRUCTOR, + expr.span, + &format!("unnecessary {} on constructor {constructor_snippet}(_)", path.ident.name), + "try", + format!("{constructor_snippet}({fun_snippet}({constructor_arg_snippet}))"), + applicability, + ); + } + } + } +} diff --git a/tests/ui/eta.fixed b/tests/ui/eta.fixed index f1cac8c5fbc6..32c7499bf73f 100644 --- a/tests/ui/eta.fixed +++ b/tests/ui/eta.fixed @@ -7,7 +7,8 @@ clippy::option_map_unit_fn, clippy::redundant_closure_call, clippy::uninlined_format_args, - clippy::useless_vec + clippy::useless_vec, + clippy::unnecessary_map_on_constructor )] use std::path::{Path, PathBuf}; diff --git a/tests/ui/eta.rs b/tests/ui/eta.rs index c7a470b5be6d..25b7431ba8cd 100644 --- a/tests/ui/eta.rs +++ b/tests/ui/eta.rs @@ -7,7 +7,8 @@ clippy::option_map_unit_fn, clippy::redundant_closure_call, clippy::uninlined_format_args, - clippy::useless_vec + clippy::useless_vec, + clippy::unnecessary_map_on_constructor )] use std::path::{Path, PathBuf}; diff --git a/tests/ui/eta.stderr b/tests/ui/eta.stderr index 7c7f17974620..951e4ac749c2 100644 --- a/tests/ui/eta.stderr +++ b/tests/ui/eta.stderr @@ -1,5 +1,5 @@ error: redundant closure - --> $DIR/eta.rs:28:27 + --> $DIR/eta.rs:29:27 | LL | let a = Some(1u8).map(|a| foo(a)); | ^^^^^^^^^^ help: replace the closure with the function itself: `foo` @@ -8,31 +8,31 @@ LL | let a = Some(1u8).map(|a| foo(a)); = help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]` error: redundant closure - --> $DIR/eta.rs:32:40 + --> $DIR/eta.rs:33:40 | LL | let _: Option> = true.then(|| vec![]); // special case vec! | ^^^^^^^^^ help: replace the closure with `Vec::new`: `std::vec::Vec::new` error: redundant closure - --> $DIR/eta.rs:33:35 + --> $DIR/eta.rs:34:35 | LL | let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted? | ^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo2` error: redundant closure - --> $DIR/eta.rs:34:26 + --> $DIR/eta.rs:35:26 | LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted | ^^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `below` error: redundant closure - --> $DIR/eta.rs:41:27 + --> $DIR/eta.rs:42:27 | LL | let e = Some(1u8).map(|a| generic(a)); | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `generic` error: redundant closure - --> $DIR/eta.rs:93:51 + --> $DIR/eta.rs:94:51 | LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo()); | ^^^^^^^^^^^ help: replace the closure with the method itself: `TestStruct::foo` @@ -41,127 +41,127 @@ LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo()); = help: to override `-D warnings` add `#[allow(clippy::redundant_closure_for_method_calls)]` error: redundant closure - --> $DIR/eta.rs:94:51 + --> $DIR/eta.rs:95:51 | LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo()); | ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `TestTrait::trait_foo` error: redundant closure - --> $DIR/eta.rs:96:42 + --> $DIR/eta.rs:97:42 | LL | let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear()); | ^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::vec::Vec::clear` error: redundant closure - --> $DIR/eta.rs:100:29 + --> $DIR/eta.rs:101:29 | LL | let e = Some("str").map(|s| s.to_string()); | ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::string::ToString::to_string` error: redundant closure - --> $DIR/eta.rs:101:27 + --> $DIR/eta.rs:102:27 | LL | let e = Some('a').map(|s| s.to_uppercase()); | ^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_uppercase` error: redundant closure - --> $DIR/eta.rs:103:65 + --> $DIR/eta.rs:104:65 | LL | let e: std::vec::Vec = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_ascii_uppercase` error: redundant closure - --> $DIR/eta.rs:166:22 + --> $DIR/eta.rs:167:22 | LL | requires_fn_once(|| x()); | ^^^^^^ help: replace the closure with the function itself: `x` error: redundant closure - --> $DIR/eta.rs:173:27 + --> $DIR/eta.rs:174:27 | LL | let a = Some(1u8).map(|a| foo_ptr(a)); | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo_ptr` error: redundant closure - --> $DIR/eta.rs:178:27 + --> $DIR/eta.rs:179:27 | LL | let a = Some(1u8).map(|a| closure(a)); | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `closure` error: redundant closure - --> $DIR/eta.rs:210:28 + --> $DIR/eta.rs:211:28 | LL | x.into_iter().for_each(|x| add_to_res(x)); | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res` error: redundant closure - --> $DIR/eta.rs:211:28 + --> $DIR/eta.rs:212:28 | LL | y.into_iter().for_each(|x| add_to_res(x)); | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res` error: redundant closure - --> $DIR/eta.rs:212:28 + --> $DIR/eta.rs:213:28 | LL | z.into_iter().for_each(|x| add_to_res(x)); | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `add_to_res` error: redundant closure - --> $DIR/eta.rs:219:21 + --> $DIR/eta.rs:220:21 | LL | Some(1).map(|n| closure(n)); | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut closure` error: redundant closure - --> $DIR/eta.rs:223:21 + --> $DIR/eta.rs:224:21 | LL | Some(1).map(|n| in_loop(n)); | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `in_loop` error: redundant closure - --> $DIR/eta.rs:316:18 + --> $DIR/eta.rs:317:18 | LL | takes_fn_mut(|| f()); | ^^^^^^ help: replace the closure with the function itself: `&mut f` error: redundant closure - --> $DIR/eta.rs:319:19 + --> $DIR/eta.rs:320:19 | LL | takes_fn_once(|| f()); | ^^^^^^ help: replace the closure with the function itself: `&mut f` error: redundant closure - --> $DIR/eta.rs:323:26 + --> $DIR/eta.rs:324:26 | LL | move || takes_fn_mut(|| f_used_once()) | ^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut f_used_once` error: redundant closure - --> $DIR/eta.rs:335:19 + --> $DIR/eta.rs:336:19 | LL | array_opt.map(|a| a.as_slice()); | ^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8; 3]>::as_slice` error: redundant closure - --> $DIR/eta.rs:338:19 + --> $DIR/eta.rs:339:19 | LL | slice_opt.map(|s| s.len()); | ^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8]>::len` error: redundant closure - --> $DIR/eta.rs:341:17 + --> $DIR/eta.rs:342:17 | LL | ptr_opt.map(|p| p.is_null()); | ^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<*const usize>::is_null` error: redundant closure - --> $DIR/eta.rs:345:17 + --> $DIR/eta.rs:346:17 | LL | dyn_opt.map(|d| d.method_on_dyn()); | ^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `::method_on_dyn` error: redundant closure - --> $DIR/eta.rs:388:19 + --> $DIR/eta.rs:389:19 | LL | let _ = f(&0, |x, y| f2(x, y)); | ^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `f2` diff --git a/tests/ui/manual_map_option.fixed b/tests/ui/manual_map_option.fixed index f6a964da418a..16cee3fd3823 100644 --- a/tests/ui/manual_map_option.fixed +++ b/tests/ui/manual_map_option.fixed @@ -5,6 +5,7 @@ clippy::unit_arg, clippy::match_ref_pats, clippy::redundant_pattern_matching, + clippy::unnecessary_map_on_constructor, for_loops_over_fallibles, dead_code )] diff --git a/tests/ui/manual_map_option.rs b/tests/ui/manual_map_option.rs index df9dc256d303..4655acf1406c 100644 --- a/tests/ui/manual_map_option.rs +++ b/tests/ui/manual_map_option.rs @@ -5,6 +5,7 @@ clippy::unit_arg, clippy::match_ref_pats, clippy::redundant_pattern_matching, + clippy::unnecessary_map_on_constructor, for_loops_over_fallibles, dead_code )] diff --git a/tests/ui/manual_map_option.stderr b/tests/ui/manual_map_option.stderr index ff6ed974d4a1..3754a982cb9b 100644 --- a/tests/ui/manual_map_option.stderr +++ b/tests/ui/manual_map_option.stderr @@ -1,5 +1,5 @@ error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:13:5 + --> $DIR/manual_map_option.rs:14:5 | LL | / match Some(0) { LL | | Some(_) => Some(2), @@ -11,7 +11,7 @@ LL | | }; = help: to override `-D warnings` add `#[allow(clippy::manual_map)]` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:18:5 + --> $DIR/manual_map_option.rs:19:5 | LL | / match Some(0) { LL | | Some(x) => Some(x + 1), @@ -20,7 +20,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(|x| x + 1)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:23:5 + --> $DIR/manual_map_option.rs:24:5 | LL | / match Some("") { LL | | Some(x) => Some(x.is_empty()), @@ -29,7 +29,7 @@ LL | | }; | |_____^ help: try: `Some("").map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:28:5 + --> $DIR/manual_map_option.rs:29:5 | LL | / if let Some(x) = Some(0) { LL | | Some(!x) @@ -39,7 +39,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(|x| !x)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:35:5 + --> $DIR/manual_map_option.rs:36:5 | LL | / match Some(0) { LL | | Some(x) => { Some(std::convert::identity(x)) } @@ -48,7 +48,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(std::convert::identity)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:40:5 + --> $DIR/manual_map_option.rs:41:5 | LL | / match Some(&String::new()) { LL | | Some(x) => Some(str::len(x)), @@ -57,7 +57,7 @@ LL | | }; | |_____^ help: try: `Some(&String::new()).map(|x| str::len(x))` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:50:5 + --> $DIR/manual_map_option.rs:51:5 | LL | / match &Some([0, 1]) { LL | | Some(x) => Some(x[0]), @@ -66,7 +66,7 @@ LL | | }; | |_____^ help: try: `Some([0, 1]).as_ref().map(|x| x[0])` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:55:5 + --> $DIR/manual_map_option.rs:56:5 | LL | / match &Some(0) { LL | | &Some(x) => Some(x * 2), @@ -75,7 +75,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(|x| x * 2)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:60:5 + --> $DIR/manual_map_option.rs:61:5 | LL | / match Some(String::new()) { LL | | Some(ref x) => Some(x.is_empty()), @@ -84,7 +84,7 @@ LL | | }; | |_____^ help: try: `Some(String::new()).as_ref().map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:65:5 + --> $DIR/manual_map_option.rs:66:5 | LL | / match &&Some(String::new()) { LL | | Some(x) => Some(x.len()), @@ -93,7 +93,7 @@ LL | | }; | |_____^ help: try: `Some(String::new()).as_ref().map(|x| x.len())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:70:5 + --> $DIR/manual_map_option.rs:71:5 | LL | / match &&Some(0) { LL | | &&Some(x) => Some(x + x), @@ -102,7 +102,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(|x| x + x)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:83:9 + --> $DIR/manual_map_option.rs:84:9 | LL | / match &mut Some(String::new()) { LL | | Some(x) => Some(x.push_str("")), @@ -111,7 +111,7 @@ LL | | }; | |_________^ help: try: `Some(String::new()).as_mut().map(|x| x.push_str(""))` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:89:5 + --> $DIR/manual_map_option.rs:90:5 | LL | / match &mut Some(String::new()) { LL | | Some(ref x) => Some(x.len()), @@ -120,7 +120,7 @@ LL | | }; | |_____^ help: try: `Some(String::new()).as_ref().map(|x| x.len())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:94:5 + --> $DIR/manual_map_option.rs:95:5 | LL | / match &mut &Some(String::new()) { LL | | Some(x) => Some(x.is_empty()), @@ -129,7 +129,7 @@ LL | | }; | |_____^ help: try: `Some(String::new()).as_ref().map(|x| x.is_empty())` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:99:5 + --> $DIR/manual_map_option.rs:100:5 | LL | / match Some((0, 1, 2)) { LL | | Some((x, y, z)) => Some(x + y + z), @@ -138,7 +138,7 @@ LL | | }; | |_____^ help: try: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:104:5 + --> $DIR/manual_map_option.rs:105:5 | LL | / match Some([1, 2, 3]) { LL | | Some([first, ..]) => Some(first), @@ -147,7 +147,7 @@ LL | | }; | |_____^ help: try: `Some([1, 2, 3]).map(|[first, ..]| first)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:109:5 + --> $DIR/manual_map_option.rs:110:5 | LL | / match &Some((String::new(), "test")) { LL | | Some((x, y)) => Some((y, x)), @@ -156,7 +156,7 @@ LL | | }; | |_____^ help: try: `Some((String::new(), "test")).as_ref().map(|(x, y)| (y, x))` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:167:5 + --> $DIR/manual_map_option.rs:168:5 | LL | / match Some(0) { LL | | Some(x) => Some(vec![x]), @@ -165,7 +165,7 @@ LL | | }; | |_____^ help: try: `Some(0).map(|x| vec![x])` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:172:5 + --> $DIR/manual_map_option.rs:173:5 | LL | / match option_env!("") { LL | | Some(x) => Some(String::from(x)), @@ -174,7 +174,7 @@ LL | | }; | |_____^ help: try: `option_env!("").map(String::from)` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:192:12 + --> $DIR/manual_map_option.rs:193:12 | LL | } else if let Some(x) = Some(0) { | ____________^ @@ -185,7 +185,7 @@ LL | | }; | |_____^ help: try: `{ Some(0).map(|x| x + 1) }` error: manual implementation of `Option::map` - --> $DIR/manual_map_option.rs:200:12 + --> $DIR/manual_map_option.rs:201:12 | LL | } else if let Some(x) = Some(0) { | ____________^ diff --git a/tests/ui/option_filter_map.fixed b/tests/ui/option_filter_map.fixed index d4c04ff907b2..ee004c0e194b 100644 --- a/tests/ui/option_filter_map.fixed +++ b/tests/ui/option_filter_map.fixed @@ -1,5 +1,5 @@ #![warn(clippy::option_filter_map)] -#![allow(clippy::map_flatten)] +#![allow(clippy::map_flatten, clippy::unnecessary_map_on_constructor)] fn main() { let _ = Some(Some(1)).flatten(); diff --git a/tests/ui/option_filter_map.rs b/tests/ui/option_filter_map.rs index 99fb4723cab7..eae2fa176a89 100644 --- a/tests/ui/option_filter_map.rs +++ b/tests/ui/option_filter_map.rs @@ -1,5 +1,5 @@ #![warn(clippy::option_filter_map)] -#![allow(clippy::map_flatten)] +#![allow(clippy::map_flatten, clippy::unnecessary_map_on_constructor)] fn main() { let _ = Some(Some(1)).filter(Option::is_some).map(Option::unwrap); diff --git a/tests/ui/result_map_unit_fn_unfixable.rs b/tests/ui/result_map_unit_fn_unfixable.rs index a4dfc8f293d3..62798b6d3d6f 100644 --- a/tests/ui/result_map_unit_fn_unfixable.rs +++ b/tests/ui/result_map_unit_fn_unfixable.rs @@ -1,6 +1,6 @@ #![warn(clippy::result_map_unit_fn)] #![feature(never_type)] -#![allow(unused)] +#![allow(unused, clippy::unnecessary_map_on_constructor)] //@no-rustfix struct HasResult { field: Result, diff --git a/tests/ui/unnecessary_map_on_constructor.fixed b/tests/ui/unnecessary_map_on_constructor.fixed new file mode 100644 index 000000000000..d0ba7ed749e4 --- /dev/null +++ b/tests/ui/unnecessary_map_on_constructor.fixed @@ -0,0 +1,56 @@ +#![allow(unused)] +#![warn(clippy::unnecessary_map_on_constructor)] + +use std::ffi::OsStr; + +fn fun(t: i32) -> i32 { + t +} + +fn notfun(e: SimpleError) -> SimpleError { + e +} +macro_rules! expands_to_fun { + () => { + fun + }; +} + +#[derive(Copy, Clone)] +struct SimpleError {} + +type SimpleResult = std::result::Result; + +fn main() { + let x: i32 = 4; + + let err = SimpleError {}; + let a = Some(x); + let b: SimpleResult = Ok(x); + let c: SimpleResult = Err(err); + + let a = Some(fun(x)); + let b: SimpleResult = Ok(fun(x)); + let c: SimpleResult = Err(notfun(err)); + + let a = Option::Some(fun(x)); + let b: SimpleResult = SimpleResult::Ok(fun(x)); + let c: SimpleResult = SimpleResult::Err(notfun(err)); + let b: std::result::Result = Ok(fun(x)); + let c: std::result::Result = Err(notfun(err)); + + let a = Some(fun(x)); + let b: SimpleResult = Ok(fun(x)); + let c: SimpleResult = Err(notfun(err)); + + // Should not trigger warning + a.map(fun); + b.map(fun); + c.map_err(notfun); + + b.map_err(notfun); // Ok(_).map_err + c.map(fun); // Err(_).map() + + option_env!("PATH").map(OsStr::new); + Some(x).map(expands_to_fun!()); +} diff --git a/tests/ui/unnecessary_map_on_constructor.rs b/tests/ui/unnecessary_map_on_constructor.rs new file mode 100644 index 000000000000..e89e7aad4c40 --- /dev/null +++ b/tests/ui/unnecessary_map_on_constructor.rs @@ -0,0 +1,56 @@ +#![allow(unused)] +#![warn(clippy::unnecessary_map_on_constructor)] + +use std::ffi::OsStr; + +fn fun(t: i32) -> i32 { + t +} + +fn notfun(e: SimpleError) -> SimpleError { + e +} +macro_rules! expands_to_fun { + () => { + fun + }; +} + +#[derive(Copy, Clone)] +struct SimpleError {} + +type SimpleResult = std::result::Result; + +fn main() { + let x: i32 = 4; + + let err = SimpleError {}; + let a = Some(x); + let b: SimpleResult = Ok(x); + let c: SimpleResult = Err(err); + + let a = Some(x).map(fun); + let b: SimpleResult = Ok(x).map(fun); + let c: SimpleResult = Err(err).map_err(notfun); + + let a = Option::Some(x).map(fun); + let b: SimpleResult = SimpleResult::Ok(x).map(fun); + let c: SimpleResult = SimpleResult::Err(err).map_err(notfun); + let b: std::result::Result = Ok(x).map(fun); + let c: std::result::Result = Err(err).map_err(notfun); + + let a = Some(fun(x)); + let b: SimpleResult = Ok(fun(x)); + let c: SimpleResult = Err(notfun(err)); + + // Should not trigger warning + a.map(fun); + b.map(fun); + c.map_err(notfun); + + b.map_err(notfun); // Ok(_).map_err + c.map(fun); // Err(_).map() + + option_env!("PATH").map(OsStr::new); + Some(x).map(expands_to_fun!()); +} diff --git a/tests/ui/unnecessary_map_on_constructor.stderr b/tests/ui/unnecessary_map_on_constructor.stderr new file mode 100644 index 000000000000..d522b68d8726 --- /dev/null +++ b/tests/ui/unnecessary_map_on_constructor.stderr @@ -0,0 +1,53 @@ +error: unnecessary map on constructor Some(_) + --> $DIR/unnecessary_map_on_constructor.rs:32:13 + | +LL | let a = Some(x).map(fun); + | ^^^^^^^^^^^^^^^^ help: try: `Some(fun(x))` + | + = note: `-D clippy::unnecessary-map-on-constructor` implied by `-D warnings` + = help: to override `-D warnings` add `#[allow(clippy::unnecessary_map_on_constructor)]` + +error: unnecessary map on constructor Ok(_) + --> $DIR/unnecessary_map_on_constructor.rs:33:27 + | +LL | let b: SimpleResult = Ok(x).map(fun); + | ^^^^^^^^^^^^^^ help: try: `Ok(fun(x))` + +error: unnecessary map_err on constructor Err(_) + --> $DIR/unnecessary_map_on_constructor.rs:34:27 + | +LL | let c: SimpleResult = Err(err).map_err(notfun); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Err(notfun(err))` + +error: unnecessary map on constructor Option::Some(_) + --> $DIR/unnecessary_map_on_constructor.rs:36:13 + | +LL | let a = Option::Some(x).map(fun); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Option::Some(fun(x))` + +error: unnecessary map on constructor SimpleResult::Ok(_) + --> $DIR/unnecessary_map_on_constructor.rs:37:27 + | +LL | let b: SimpleResult = SimpleResult::Ok(x).map(fun); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `SimpleResult::Ok(fun(x))` + +error: unnecessary map_err on constructor SimpleResult::Err(_) + --> $DIR/unnecessary_map_on_constructor.rs:38:27 + | +LL | let c: SimpleResult = SimpleResult::Err(err).map_err(notfun); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `SimpleResult::Err(notfun(err))` + +error: unnecessary map on constructor Ok(_) + --> $DIR/unnecessary_map_on_constructor.rs:39:52 + | +LL | let b: std::result::Result = Ok(x).map(fun); + | ^^^^^^^^^^^^^^ help: try: `Ok(fun(x))` + +error: unnecessary map_err on constructor Err(_) + --> $DIR/unnecessary_map_on_constructor.rs:40:52 + | +LL | let c: std::result::Result = Err(err).map_err(notfun); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Err(notfun(err))` + +error: aborting due to 8 previous errors +