diff options
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 38 | ||||
| -rw-r--r-- | src/lintlist/mod.rs | 2 | ||||
| -rw-r--r-- | tests/ui/methods.rs | 23 | ||||
| -rw-r--r-- | tests/ui/methods.stderr | 2 |
4 files changed, 57 insertions, 8 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index b6fb3d06934..bd04a95e4a1 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -515,11 +515,11 @@ declare_clippy_lint! { } declare_clippy_lint! { - /// **What it does:** Checks for an iterator search (such as `find()`, + /// **What it does:** Checks for an iterator or string search (such as `find()`, /// `position()`, or `rposition()`) followed by a call to `is_some()`. /// /// **Why is this bad?** Readability, this can be written more concisely as - /// `_.any(_)`. + /// `_.any(_)` or `_.contains(_)`. /// /// **Known problems:** None. /// @@ -535,7 +535,7 @@ declare_clippy_lint! { /// ``` pub SEARCH_IS_SOME, complexity, - "using an iterator search followed by `is_some()`, which is more succinctly expressed as a call to `any()`" + "using an iterator or string search followed by `is_some()`, which is more succinctly expressed as a call to `any()` or `contains()`" } declare_clippy_lint! { @@ -3041,6 +3041,7 @@ fn lint_flat_map_identity<'tcx>( } /// lint searching an Iterator followed by `is_some()` +/// or calling `find()` on a string followed by `is_some()` fn lint_search_is_some<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, @@ -3094,6 +3095,37 @@ fn lint_search_is_some<'tcx>( span_lint(cx, SEARCH_IS_SOME, expr.span, &msg); } } + // lint if `find()` is called by `String` or `&str` + else if search_method == "find" { + let is_string_or_str_slice = |e| { + let self_ty = cx.typeck_results().expr_ty(e).peel_refs(); + if is_type_diagnostic_item(cx, self_ty, sym!(string_type)) { + true + } else { + *self_ty.kind() == ty::Str + } + }; + if_chain! { + if is_string_or_str_slice(&search_args[0]); + if is_string_or_str_slice(&search_args[1]); + then { + let msg = "called `is_some()` after calling `find()` \ + on a string. This is more succinctly expressed by calling \ + `contains()`.".to_string(); + let mut applicability = Applicability::MachineApplicable; + let find_arg = snippet_with_applicability(cx, search_args[1].span, "..", &mut applicability); + span_lint_and_sugg( + cx, + SEARCH_IS_SOME, + method_span.with_hi(expr.span.hi()), + &msg, + "try this", + format!("contains({})", find_arg), + applicability, + ); + } + } + } } /// Used for `lint_binary_expr_with_method_call`. diff --git a/src/lintlist/mod.rs b/src/lintlist/mod.rs index 4f1b56ed9be..69acd3d9b8b 100644 --- a/src/lintlist/mod.rs +++ b/src/lintlist/mod.rs @@ -2121,7 +2121,7 @@ vec![ Lint { name: "search_is_some", group: "complexity", - desc: "using an iterator search followed by `is_some()`, which is more succinctly expressed as a call to `any()`", + desc: "using an iterator or string search followed by `is_some()`, which is more succinctly expressed as a call to `any()` or `contains()`", deprecation: None, module: "methods", }, diff --git a/tests/ui/methods.rs b/tests/ui/methods.rs index d93e5b114ec..92ec00a11d2 100644 --- a/tests/ui/methods.rs +++ b/tests/ui/methods.rs @@ -168,8 +168,27 @@ fn search_is_some() { x < 0 } ).is_some(); - - // Check that we don't lint if the caller is not an `Iterator`. + + let s1 = String::from("hello world"); + let s2 = String::from("world"); + // Check caller `find()` is a &`static str case + let _ = "hello world".find("world").is_some(); + let _ = "hello world".find(&s2).is_some(); + let _ = "hello world".find(&s2[2..]).is_some(); + // Check caller of `find()` is a String case + let _ = s1.find("world").is_some(); + let _ = s1.find(&s2).is_some(); + let _ = s1.find(&s2[2..]).is_some(); + // Check caller of `find()` is a slice of String case + let _ = s1[2..].find("world").is_some(); + let _ = s1[2..].find(&s2).is_some(); + let _ = s1[2..].find(&s2[2..]).is_some(); + + // Check that we don't lint if `find()` is called with + // Pattern that is not a string + let _ = s1.find(|c: char| c == 'o' || c == 'l').is_some(); + + // Check that we don't lint if the caller is not an `Iterator` or string let foo = IteratorFalsePositives { foo: 0 }; let _ = foo.find().is_some(); let _ = foo.position().is_some(); diff --git a/tests/ui/methods.stderr b/tests/ui/methods.stderr index 8a281c2dbd2..b2b551bd5f8 100644 --- a/tests/ui/methods.stderr +++ b/tests/ui/methods.stderr @@ -88,5 +88,3 @@ LL | | } LL | | ).is_some(); | |______________________________^ -error: aborting due to 11 previous errors - |