From db3177a5aa5cf8a4c712fc17ef1407dd1e4f883e Mon Sep 17 00:00:00 2001
From: WindSoilder <WindSoilder@outlook.com>
Date: Wed, 14 Dec 2022 23:20:18 +0800
Subject: [PATCH] break `for`, `loop`, `while` execution when external command
 runs to failed (#7475)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixes: #7467

# User-Facing Changes

## for
```
❯ for i in 1..2 { echo 1;  ^false }
1
```

## loop
```
❯ loop { echo bb; ^false }
bb
```

## while
```
❯ mut x = 1; while $x < 3 { $x = $x + 1; echo bb; ^false }
bb
```
---
 crates/nu-command/src/core_commands/for_.rs   | 10 +++++++--
 crates/nu-command/src/core_commands/loop_.rs  |  5 ++++-
 crates/nu-command/src/core_commands/while_.rs |  6 +++++-
 crates/nu-command/tests/commands/for_.rs      | 15 +++++++++++++
 crates/nu-command/tests/commands/loop_.rs     | 21 +++++++++++++++++++
 crates/nu-command/tests/commands/while_.rs    | 11 ++++++++++
 6 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/crates/nu-command/src/core_commands/for_.rs b/crates/nu-command/src/core_commands/for_.rs
index 3889d9ec7c..c56fd1fca6 100644
--- a/crates/nu-command/src/core_commands/for_.rs
+++ b/crates/nu-command/src/core_commands/for_.rs
@@ -118,7 +118,10 @@ impl Command for For {
                             return Err(err);
                         }
                         Ok(pipeline) => {
-                            let _ = pipeline.print(&engine_state, stack, false, false)?;
+                            let exit_code = pipeline.print(&engine_state, stack, false, false)?;
+                            if exit_code != 0 {
+                                break;
+                            }
                         }
                     }
                 }
@@ -157,7 +160,10 @@ impl Command for For {
                             return Err(err);
                         }
                         Ok(pipeline) => {
-                            let _ = pipeline.print(&engine_state, stack, false, false)?;
+                            let exit_code = pipeline.print(&engine_state, stack, false, false)?;
+                            if exit_code != 0 {
+                                break;
+                            }
                         }
                     }
                 }
diff --git a/crates/nu-command/src/core_commands/loop_.rs b/crates/nu-command/src/core_commands/loop_.rs
index 3ca8188f71..1b4befd871 100644
--- a/crates/nu-command/src/core_commands/loop_.rs
+++ b/crates/nu-command/src/core_commands/loop_.rs
@@ -69,7 +69,10 @@ impl Command for Loop {
                     return Err(err);
                 }
                 Ok(pipeline) => {
-                    let _ = pipeline.print(engine_state, stack, false, false)?;
+                    let exit_code = pipeline.print(engine_state, stack, false, false)?;
+                    if exit_code != 0 {
+                        break;
+                    }
                 }
             }
         }
diff --git a/crates/nu-command/src/core_commands/while_.rs b/crates/nu-command/src/core_commands/while_.rs
index eb4237a85c..57b4da9b4c 100644
--- a/crates/nu-command/src/core_commands/while_.rs
+++ b/crates/nu-command/src/core_commands/while_.rs
@@ -77,7 +77,11 @@ impl Command for While {
                                 return Err(err);
                             }
                             Ok(pipeline) => {
-                                let _ = pipeline.print(engine_state, stack, false, false)?;
+                                let exit_code =
+                                    pipeline.print(engine_state, stack, false, false)?;
+                                if exit_code != 0 {
+                                    break;
+                                }
                             }
                         }
                     } else {
diff --git a/crates/nu-command/tests/commands/for_.rs b/crates/nu-command/tests/commands/for_.rs
index 0e480db355..2a6e3ca83f 100644
--- a/crates/nu-command/tests/commands/for_.rs
+++ b/crates/nu-command/tests/commands/for_.rs
@@ -14,3 +14,18 @@ fn for_auto_print_in_each_iteration() {
     // that's ok, our main concern is it auto print value in each iteration.
     assert_eq!(actual.out, "11");
 }
+
+#[test]
+fn for_break_on_external_failed() {
+    let actual = nu!(
+        cwd: ".",
+        r#"
+        for i in 1..2 {
+            echo 1;
+            nu --testbin fail
+        }"#
+    );
+    // Note: nu! macro auto repalce "\n" and "\r\n" with ""
+    // so our output will be `1`
+    assert_eq!(actual.out, "1");
+}
diff --git a/crates/nu-command/tests/commands/loop_.rs b/crates/nu-command/tests/commands/loop_.rs
index fef9ce78a2..c61ad6cf78 100644
--- a/crates/nu-command/tests/commands/loop_.rs
+++ b/crates/nu-command/tests/commands/loop_.rs
@@ -20,3 +20,24 @@ fn loop_auto_print_in_each_iteration() {
     // that's ok, our main concern is it auto print value in each iteration.
     assert_eq!(actual.out, "111");
 }
+
+#[test]
+fn loop_break_on_external_failed() {
+    let actual = nu!(
+        cwd: ".",
+        r#"
+        mut total = 0;
+        loop {
+            if $total == 3 {
+                break;
+            } else {
+                $total += 1;
+            }
+            echo 1;
+            nu --testbin fail;
+        }"#
+    );
+    // Note: nu! macro auto repalce "\n" and "\r\n" with ""
+    // so our output will be `1`.
+    assert_eq!(actual.out, "1");
+}
diff --git a/crates/nu-command/tests/commands/while_.rs b/crates/nu-command/tests/commands/while_.rs
index 77b430ec56..66556f45e1 100644
--- a/crates/nu-command/tests/commands/while_.rs
+++ b/crates/nu-command/tests/commands/while_.rs
@@ -21,3 +21,14 @@ fn while_auto_print_in_each_iteration() {
     // that's ok, our main concern is it auto print value in each iteration.
     assert_eq!(actual.out, "11");
 }
+
+#[test]
+fn while_break_on_external_failed() {
+    let actual = nu!(
+        cwd: ".",
+        "mut total = 0; while $total < 2 { $total = $total + 1; echo 1; nu --testbin fail }"
+    );
+    // Note: nu! macro auto repalce "\n" and "\r\n" with ""
+    // so our output will be `1`
+    assert_eq!(actual.out, "1");
+}