Only lint Copy types

clippy_lints/src/methods/filter_map_bool_then.rs

@@ -1,28 +1,34 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::paths::BOOL_THEN;
 use clippy_utils::source::snippet_opt;
-use clippy_utils::{is_from_proc_macro, match_def_path, peel_blocks};
+use clippy_utils::ty::is_copy;
+use clippy_utils::{is_from_proc_macro, is_trait_method, match_def_path, peel_blocks};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_span::Span;
+use rustc_span::{sym, Span};
 
 use super::FILTER_MAP_BOOL_THEN;
 
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, arg: &Expr<'_>, call_span: Span) {
     if !in_external_macro(cx.sess(), expr.span)
+        && is_trait_method(cx, expr, sym::Iterator)
         && let ExprKind::Closure(closure) = arg.kind
-        && let body = peel_blocks(cx.tcx.hir().body(closure.body).value)
-        && let ExprKind::MethodCall(_, recv, [then_arg], _) = body.kind
+        && let body = cx.tcx.hir().body(closure.body)
+        && let value = peel_blocks(body.value)
+        // Indexing should be fine as `filter_map` always has 1 input, we unfortunately need both
+        // `inputs` and `params` here as we need both the type and the span
+        && let param_ty = closure.fn_decl.inputs[0]
+        && let param = body.params[0]
+        && is_copy(cx, cx.typeck_results().node_type(param_ty.hir_id).peel_refs())
+        && let ExprKind::MethodCall(_, recv, [then_arg], _) = value.kind
         && let ExprKind::Closure(then_closure) = then_arg.kind
         && let then_body = peel_blocks(cx.tcx.hir().body(then_closure.body).value)
-        && let Some(def_id) = cx.typeck_results().type_dependent_def_id(body.hir_id)
+        && let Some(def_id) = cx.typeck_results().type_dependent_def_id(value.hir_id)
         && match_def_path(cx, def_id, &BOOL_THEN)
         && !is_from_proc_macro(cx, expr)
-        && let Some(decl_snippet) = closure.fn_arg_span.and_then(|s| snippet_opt(cx, s))
-        // NOTE: This will include the `()` (parenthesis) around it. Maybe there's some utils method
-        // to remove them? `unused_parens` will already take care of this but it may be nice.
+        && let Some(param_snippet) = snippet_opt(cx, param.span)
         && let Some(filter) = snippet_opt(cx, recv.span)
         && let Some(map) = snippet_opt(cx, then_body.span)
     {
@@ -32,7 +38,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, arg: &
             call_span,
             "usage of `bool::then` in `filter_map`",
             "use `filter` then `map` instead",
-            format!("filter({decl_snippet} {filter}).map({decl_snippet} {map})"),
+            format!("filter(|&{param_snippet}| {filter}).map(|{param_snippet}| {map})"),
             Applicability::MachineApplicable,
         );
     }

tests/ui/filter_map_bool_then.fixed

@@ -1,26 +1,37 @@
 //@run-rustfix
 //@aux-build:proc_macros.rs:proc-macro
-#![allow(clippy::clone_on_copy, clippy::unnecessary_lazy_evaluations, unused)]
+#![allow(
+    clippy::clone_on_copy,
+    clippy::map_identity,
+    clippy::unnecessary_lazy_evaluations,
+    unused
+)]
 #![warn(clippy::filter_map_bool_then)]
 
 #[macro_use]
 extern crate proc_macros;
 
+#[derive(Clone, PartialEq)]
+struct NonCopy;
+
 fn main() {
     let v = vec![1, 2, 3, 4, 5, 6];
-    v.clone().into_iter().filter(|i| (i % 2 == 0)).map(|i| i + 1);
+    v.clone().iter().filter(|&i| (i % 2 == 0)).map(|i| i + 1);
+    v.clone().into_iter().filter(|&i| (i % 2 == 0)).map(|i| i + 1);
     v.clone()
         .into_iter()
-        .filter(|i| (i % 2 == 0)).map(|i| i + 1);
+        .filter(|&i| (i % 2 == 0)).map(|i| i + 1);
     v.clone()
         .into_iter()
         .filter(|&i| i != 1000)
-        .filter(|i| (i % 2 == 0)).map(|i| i + 1);
+        .filter(|&i| (i % 2 == 0)).map(|i| i + 1);
     v.iter()
         .copied()
         .filter(|&i| i != 1000)
-        .filter(|i| (i.clone() % 2 == 0)).map(|i| i + 1);
+        .filter(|&i| (i.clone() % 2 == 0)).map(|i| i + 1);
     // Do not lint
+    let v = vec![NonCopy, NonCopy];
+    v.clone().iter().filter_map(|i| (i == &NonCopy).then(|| i));
     external! {
         let v = vec![1, 2, 3, 4, 5, 6];
         v.clone().into_iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));

tests/ui/filter_map_bool_then.rs

@@ -1,13 +1,22 @@
 //@run-rustfix
 //@aux-build:proc_macros.rs:proc-macro
-#![allow(clippy::clone_on_copy, clippy::unnecessary_lazy_evaluations, unused)]
+#![allow(
+    clippy::clone_on_copy,
+    clippy::map_identity,
+    clippy::unnecessary_lazy_evaluations,
+    unused
+)]
 #![warn(clippy::filter_map_bool_then)]
 
 #[macro_use]
 extern crate proc_macros;
 
+#[derive(Clone, PartialEq)]
+struct NonCopy;
+
 fn main() {
     let v = vec![1, 2, 3, 4, 5, 6];
+    v.clone().iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));
     v.clone().into_iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));
     v.clone()
         .into_iter()
@@ -21,6 +30,8 @@ fn main() {
         .filter(|&i| i != 1000)
         .filter_map(|i| (i.clone() % 2 == 0).then(|| i + 1));
     // Do not lint
+    let v = vec![NonCopy, NonCopy];
+    v.clone().iter().filter_map(|i| (i == &NonCopy).then(|| i));
     external! {
         let v = vec![1, 2, 3, 4, 5, 6];
         v.clone().into_iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));

tests/ui/filter_map_bool_then.stderr

@@ -1,28 +1,34 @@
 error: usage of `bool::then` in `filter_map`
-  --> $DIR/filter_map_bool_then.rs:11:27
+  --> $DIR/filter_map_bool_then.rs:19:22
    |
-LL |     v.clone().into_iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|i| (i % 2 == 0)).map(|i| i + 1)`
+LL |     v.clone().iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|&i| (i % 2 == 0)).map(|i| i + 1)`
    |
    = note: `-D clippy::filter-map-bool-then` implied by `-D warnings`
 
 error: usage of `bool::then` in `filter_map`
-  --> $DIR/filter_map_bool_then.rs:14:10
+  --> $DIR/filter_map_bool_then.rs:20:27
+   |
+LL |     v.clone().into_iter().filter_map(|i| (i % 2 == 0).then(|| i + 1));
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|&i| (i % 2 == 0)).map(|i| i + 1)`
+
+error: usage of `bool::then` in `filter_map`
+  --> $DIR/filter_map_bool_then.rs:23:10
    |
 LL |         .filter_map(|i| -> Option<_> { (i % 2 == 0).then(|| i + 1) });
-   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|i| (i % 2 == 0)).map(|i| i + 1)`
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|&i| (i % 2 == 0)).map(|i| i + 1)`
 
 error: usage of `bool::then` in `filter_map`
-  --> $DIR/filter_map_bool_then.rs:18:10
+  --> $DIR/filter_map_bool_then.rs:27:10
    |
 LL |         .filter_map(|i| (i % 2 == 0).then(|| i + 1));
-   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|i| (i % 2 == 0)).map(|i| i + 1)`
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|&i| (i % 2 == 0)).map(|i| i + 1)`
 
 error: usage of `bool::then` in `filter_map`
-  --> $DIR/filter_map_bool_then.rs:22:10
+  --> $DIR/filter_map_bool_then.rs:31:10
    |
 LL |         .filter_map(|i| (i.clone() % 2 == 0).then(|| i + 1));
-   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|i| (i.clone() % 2 == 0)).map(|i| i + 1)`
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `filter` then `map` instead: `filter(|&i| (i.clone() % 2 == 0)).map(|i| i + 1)`
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors