1 files changed, 204 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/never_loop.rs b/src/tools/clippy/tests/ui/never_loop.rs
new file mode 100644
index 00000000000..cbc4ca39161
--- /dev/null
+++ b/src/tools/clippy/tests/ui/never_loop.rs
@@ -0,0 +1,204 @@
+#![allow(
+    clippy::single_match,
+    unused_assignments,
+    unused_variables,
+    clippy::while_immutable_condition
+)]
+
+fn test1() {
+    let mut x = 0;
+    loop {
+        // clippy::never_loop
+        x += 1;
+        if x == 1 {
+            return;
+        }
+        break;
+    }
+}
+
+fn test2() {
+    let mut x = 0;
+    loop {
+        x += 1;
+        if x == 1 {
+            break;
+        }
+    }
+}
+
+fn test3() {
+    let mut x = 0;
+    loop {
+        // never loops
+        x += 1;
+        break;
+    }
+}
+
+fn test4() {
+    let mut x = 1;
+    loop {
+        x += 1;
+        match x {
+            5 => return,
+            _ => (),
+        }
+    }
+}
+
+fn test5() {
+    let i = 0;
+    loop {
+        // never loops
+        while i == 0 {
+            // never loops
+            break;
+        }
+        return;
+    }
+}
+
+fn test6() {
+    let mut x = 0;
+    'outer: loop {
+        x += 1;
+        loop {
+            // never loops
+            if x == 5 {
+                break;
+            }
+            continue 'outer;
+        }
+        return;
+    }
+}
+
+fn test7() {
+    let mut x = 0;
+    loop {
+        x += 1;
+        match x {
+            1 => continue,
+            _ => (),
+        }
+        return;
+    }
+}
+
+fn test8() {
+    let mut x = 0;
+    loop {
+        x += 1;
+        match x {
+            5 => return,
+            _ => continue,
+        }
+    }
+}
+
+fn test9() {
+    let x = Some(1);
+    while let Some(y) = x {
+        // never loops
+        return;
+    }
+}
+
+fn test10() {
+    for x in 0..10 {
+        // never loops
+        match x {
+            1 => break,
+            _ => return,
+        }
+    }
+}
+
+fn test11<F: FnMut() -> i32>(mut f: F) {
+    loop {
+        return match f() {
+            1 => continue,
+            _ => (),
+        };
+    }
+}
+
+pub fn test12(a: bool, b: bool) {
+    'label: loop {
+        loop {
+            if a {
+                continue 'label;
+            }
+            if b {
+                break;
+            }
+        }
+        break;
+    }
+}
+
+pub fn test13() {
+    let mut a = true;
+    loop {
+        // infinite loop
+        while a {
+            if true {
+                a = false;
+                continue;
+            }
+            return;
+        }
+    }
+}
+
+pub fn test14() {
+    let mut a = true;
+    'outer: while a {
+        // never loops
+        while a {
+            if a {
+                a = false;
+                continue;
+            }
+        }
+        break 'outer;
+    }
+}
+
+// Issue #1991: the outter loop should not warn.
+pub fn test15() {
+    'label: loop {
+        while false {
+            break 'label;
+        }
+    }
+}
+
+// Issue #4058: `continue` in `break` expression
+pub fn test16() {
+    let mut n = 1;
+    loop {
+        break if n != 5 {
+            n += 1;
+            continue;
+        };
+    }
+}
+
+fn main() {
+    test1();
+    test2();
+    test3();
+    test4();
+    test5();
+    test6();
+    test7();
+    test8();
+    test9();
+    test10();
+    test11(|| 0);
+    test12(true, false);
+    test13();
+    test14();
+}