From dc3b8bef8052a6dbd877cd9ecc4c26592685aa4c Mon Sep 17 00:00:00 2001
From: klensy <klensy@users.noreply.github.com>
Date: Tue, 17 Jun 2025 17:21:46 +0300
Subject: [PATCH 1/2] precommit test

---
 tests/ui/or_fun_call.fixed | 18 ++++++++++++++++++
 tests/ui/or_fun_call.rs    | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/tests/ui/or_fun_call.fixed b/tests/ui/or_fun_call.fixed
index 34f3e0468419..bb46ce044661 100644
--- a/tests/ui/or_fun_call.fixed
+++ b/tests/ui/or_fun_call.fixed
@@ -439,4 +439,22 @@ fn test_option_get_or_insert() {
     //~^ or_fun_call
 }
 
+fn test_option_and() {
+    // assume that this is slow call
+    fn g() -> Option<u8> {
+        Some(99)
+    }
+    let mut x = Some(42_u8);
+    let _ = x.and(g());
+}
+
+fn test_result_and() {
+    // assume that this is slow call
+    fn g() -> Result<u8, ()> {
+        Ok(99)
+    }
+    let mut x: Result<u8, ()> = Ok(42);
+    let _ = x.and(g());
+}
+
 fn main() {}
diff --git a/tests/ui/or_fun_call.rs b/tests/ui/or_fun_call.rs
index dc57bd6060ac..68ef244a019b 100644
--- a/tests/ui/or_fun_call.rs
+++ b/tests/ui/or_fun_call.rs
@@ -439,4 +439,22 @@ fn test_option_get_or_insert() {
     //~^ or_fun_call
 }
 
+fn test_option_and() {
+    // assume that this is slow call
+    fn g() -> Option<u8> {
+        Some(99)
+    }
+    let mut x = Some(42_u8);
+    let _ = x.and(g());
+}
+
+fn test_result_and() {
+    // assume that this is slow call
+    fn g() -> Result<u8, ()> {
+        Ok(99)
+    }
+    let mut x: Result<u8, ()> = Ok(42);
+    let _ = x.and(g());
+}
+
 fn main() {}

From a82c142f3e0be8f88e588a18bf897899d30f179d Mon Sep 17 00:00:00 2001
From: klensy <klensy@users.noreply.github.com>
Date: Tue, 17 Jun 2025 17:27:56 +0300
Subject: [PATCH 2/2] or_fun_call: lint Option/Result::and(_then) too

---
 clippy_lints/src/methods/or_fun_call.rs |  4 +++-
 tests/ui/or_fun_call.fixed              |  6 ++++--
 tests/ui/or_fun_call.rs                 |  2 ++
 tests/ui/or_fun_call.stderr             | 14 +++++++++++++-
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/clippy_lints/src/methods/or_fun_call.rs b/clippy_lints/src/methods/or_fun_call.rs
index 2139466ce746..6ce7dd3d4d0a 100644
--- a/clippy_lints/src/methods/or_fun_call.rs
+++ b/clippy_lints/src/methods/or_fun_call.rs
@@ -136,7 +136,7 @@ pub(super) fn check<'tcx>(
         fun_span: Option<Span>,
     ) -> bool {
         // (path, fn_has_argument, methods, suffix)
-        const KNOW_TYPES: [(Symbol, bool, &[Symbol], &str); 5] = [
+        const KNOW_TYPES: [(Symbol, bool, &[Symbol], &str); 7] = [
             (sym::BTreeEntry, false, &[sym::or_insert], "with"),
             (sym::HashMapEntry, false, &[sym::or_insert], "with"),
             (
@@ -146,7 +146,9 @@ pub(super) fn check<'tcx>(
                 "else",
             ),
             (sym::Option, false, &[sym::get_or_insert], "with"),
+            (sym::Option, true, &[sym::and], "then"),
             (sym::Result, true, &[sym::map_or, sym::or, sym::unwrap_or], "else"),
+            (sym::Result, true, &[sym::and], "then"),
         ];
 
         if KNOW_TYPES.iter().any(|k| k.2.contains(&name))
diff --git a/tests/ui/or_fun_call.fixed b/tests/ui/or_fun_call.fixed
index bb46ce044661..bcd2602edb6a 100644
--- a/tests/ui/or_fun_call.fixed
+++ b/tests/ui/or_fun_call.fixed
@@ -445,7 +445,8 @@ fn test_option_and() {
         Some(99)
     }
     let mut x = Some(42_u8);
-    let _ = x.and(g());
+    let _ = x.and_then(|_| g());
+    //~^ or_fun_call
 }
 
 fn test_result_and() {
@@ -454,7 +455,8 @@ fn test_result_and() {
         Ok(99)
     }
     let mut x: Result<u8, ()> = Ok(42);
-    let _ = x.and(g());
+    let _ = x.and_then(|_| g());
+    //~^ or_fun_call
 }
 
 fn main() {}
diff --git a/tests/ui/or_fun_call.rs b/tests/ui/or_fun_call.rs
index 68ef244a019b..8d1202ebf914 100644
--- a/tests/ui/or_fun_call.rs
+++ b/tests/ui/or_fun_call.rs
@@ -446,6 +446,7 @@ fn test_option_and() {
     }
     let mut x = Some(42_u8);
     let _ = x.and(g());
+    //~^ or_fun_call
 }
 
 fn test_result_and() {
@@ -455,6 +456,7 @@ fn test_result_and() {
     }
     let mut x: Result<u8, ()> = Ok(42);
     let _ = x.and(g());
+    //~^ or_fun_call
 }
 
 fn main() {}
diff --git a/tests/ui/or_fun_call.stderr b/tests/ui/or_fun_call.stderr
index 0f159fe8bff4..585ee2d0e19d 100644
--- a/tests/ui/or_fun_call.stderr
+++ b/tests/ui/or_fun_call.stderr
@@ -264,5 +264,17 @@ error: function call inside of `get_or_insert`
 LL |     let _ = x.get_or_insert(g());
    |               ^^^^^^^^^^^^^^^^^^ help: try: `get_or_insert_with(g)`
 
-error: aborting due to 41 previous errors
+error: function call inside of `and`
+  --> tests/ui/or_fun_call.rs:448:15
+   |
+LL |     let _ = x.and(g());
+   |               ^^^^^^^^ help: try: `and_then(|_| g())`
+
+error: function call inside of `and`
+  --> tests/ui/or_fun_call.rs:458:15
+   |
+LL |     let _ = x.and(g());
+   |               ^^^^^^^^ help: try: `and_then(|_| g())`
+
+error: aborting due to 43 previous errors