From 7a7fcc0eda1d62f44ec374bad3d14226888238ad Mon Sep 17 00:00:00 2001
From: Takayuki Maeda <takoyaki0316@gmail.com>
Date: Wed, 17 Mar 2021 14:14:06 +0900
Subject: [PATCH] extract condition for into_iter_on_ref to its own module

---
 clippy_lints/src/methods/into_iter_on_ref.rs | 47 ++++++++++++--------
 clippy_lints/src/methods/mod.rs              |  7 +--
 2 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/clippy_lints/src/methods/into_iter_on_ref.rs b/clippy_lints/src/methods/into_iter_on_ref.rs
index cfe749cf361..5d59fa86c9e 100644
--- a/clippy_lints/src/methods/into_iter_on_ref.rs
+++ b/clippy_lints/src/methods/into_iter_on_ref.rs
@@ -1,32 +1,43 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::ty::has_iter_method;
 use clippy_utils::{match_trait_method, paths};
+use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::source_map::Span;
-use rustc_span::symbol::Symbol;
+use rustc_span::symbol::{sym, Symbol};
 
 use super::INTO_ITER_ON_REF;
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_>, method_span: Span) {
-    if !match_trait_method(cx, expr, &paths::INTO_ITERATOR) {
-        return;
-    }
-    if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ref_ty) {
-        span_lint_and_sugg(
-            cx,
-            INTO_ITER_ON_REF,
-            method_span,
-            &format!(
-                "this `.into_iter()` call is equivalent to `.{}()` and will not consume the `{}`",
-                method_name, kind,
-            ),
-            "call directly",
-            method_name.to_string(),
-            Applicability::MachineApplicable,
-        );
+pub(super) fn check(
+    cx: &LateContext<'_>,
+    expr: &hir::Expr<'_>,
+    method_span: Span,
+    method_name: Symbol,
+    args: &[hir::Expr<'_>],
+) {
+    let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]);
+    if_chain! {
+        if let ty::Ref(..) = self_ty.kind();
+        if method_name == sym::into_iter;
+        if match_trait_method(cx, expr, &paths::INTO_ITERATOR);
+        if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ty);
+        then {
+            span_lint_and_sugg(
+                cx,
+                INTO_ITER_ON_REF,
+                method_span,
+                &format!(
+                    "this `.into_iter()` call is equivalent to `.{}()` and will not consume the `{}`",
+                    method_name, kind,
+                ),
+                "call directly",
+                method_name.to_string(),
+                Applicability::MachineApplicable,
+            );
+        }
     }
 }
 
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index 808b64d9493..e8cefbd7422 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -1786,9 +1786,9 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                 clone_on_ref_ptr::check(cx, expr, method_call.ident.name, args);
                 inefficient_to_string::check(cx, expr, method_call.ident.name, args);
                 single_char_add_str::check(cx, expr, args);
+                into_iter_on_ref::check(cx, expr, *method_span, method_call.ident.name, args);
 
-                let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]);
-                match self_ty.kind() {
+                match cx.typeck_results().expr_ty_adjusted(&args[0]).kind() {
                     ty::Ref(_, ty, _) if *ty.kind() == ty::Str => {
                         for &(method, pos) in &PATTERN_METHODS {
                             if method_call.ident.name.as_str() == method && args.len() > pos {
@@ -1796,9 +1796,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                             }
                         }
                     },
-                    ty::Ref(..) if method_call.ident.name == sym::into_iter => {
-                        into_iter_on_ref::check(cx, expr, self_ty, *method_span);
-                    },
                     _ => (),
                 }
             },