move into_iter_on_ref and single_char_pattern to their own modules

1 files changed, 23 insertions, 0 deletions

diff --git a/clippy_lints/src/methods/single_char_pattern.rs b/clippy_lints/src/methods/single_char_pattern.rs
new file mode 100644
index 00000000000..61cbc9d2f0a
--- /dev/null
+++ b/clippy_lints/src/methods/single_char_pattern.rs
@@ -0,0 +1,23 @@
+use crate::methods::get_hint_if_single_char_arg;
+use crate::utils::span_lint_and_sugg;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::LateContext;
+
+use super::SINGLE_CHAR_PATTERN;
+
+/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
+pub(super) fn check(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
+    let mut applicability = Applicability::MachineApplicable;
+    if let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability) {
+        span_lint_and_sugg(
+            cx,
+            SINGLE_CHAR_PATTERN,
+            arg.span,
+            "single-character string constant used as pattern",
+            "try using a `char` instead",
+            hint,
+            applicability,
+        );
+    }
+}