Loops return external stream when external command failed. (#8646)

crates/nu-command/tests/commands/for_.rs

@@ -28,3 +28,27 @@ fn for_break_on_external_failed() {
     // so our output will be `1`
     assert_eq!(actual.out, "1");
 }
+
+#[test]
+fn failed_for_should_break_running() {
+    let actual = nu!(
+        cwd: ".",
+        r#"
+        for i in 1..2 {
+            nu --testbin fail
+        }
+        print 3"#
+    );
+    assert!(!actual.out.contains('3'));
+
+    let actual = nu!(
+        cwd: ".",
+        r#"
+        let x = [1 2]
+        for i in $x {
+            nu --testbin fail
+        }
+        print 3"#
+    );
+    assert!(!actual.out.contains('3'));
+}

crates/nu-command/tests/commands/loop_.rs

@@ -40,3 +40,22 @@ fn loop_break_on_external_failed() {
     // so our output will be `1`.
     assert_eq!(actual.out, "1");
 }
+
+#[test]
+fn failed_loop_should_break_running() {
+    let actual = nu!(
+        cwd: ".",
+        r#"
+        mut total = 0;
+        loop {
+            if $total == 3 {
+                break;
+            } else {
+                $total += 1;
+            }
+            nu --testbin fail;
+        }
+        print 3"#
+    );
+    assert!(!actual.out.contains('3'));
+}

crates/nu-command/tests/commands/while_.rs

@@ -31,3 +31,12 @@ fn while_break_on_external_failed() {
     // so our output will be `1`
     assert_eq!(actual.out, "1");
 }
+
+#[test]
+fn failed_while_should_break_running() {
+    let actual = nu!(
+        cwd: ".",
+        "mut total = 0; while $total < 2 { $total = $total + 1; nu --testbin fail }; print 3"
+    );
+    assert!(!actual.out.contains('3'));
+}