From b22d13127945a5f49d98efea6b9d03761c6e5b76 Mon Sep 17 00:00:00 2001
From: pwygab <88221256+merelymyself@users.noreply.github.com>
Date: Thu, 2 May 2024 06:24:54 +0800
Subject: [PATCH] Prevent `each` from swallowing errors when `eval_block`
 returns a `ListStream` (#12412)
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# Description
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Prior, it seemed that nested errors would not get detected and shown.
This PR fixes that.

Resolves #10176:
```
~/CodingProjects/nushell> [[1,2]] | each {|x| $x | each {|y| error make {msg: "oh noes"} } }                        05/04/2024 21:34:08
Error: nu::shell::eval_block_with_input

  × Eval block failed with pipeline input
   ╭─[entry #1:1:3]
 1 │ [[1,2]] | each {|x| $x | each {|y| error make {msg: "oh noes"} } }
   ·   ┬
   ·   ╰── source value
   ╰────

Error:   × oh noes
   ╭─[entry #1:1:36]
 1 │ [[1,2]] | each {|x| $x | each {|y| error make {msg: "oh noes"} } }
   ·                                    ─────┬────
   ·                                         ╰── originates from here
   ╰────
```

Resolves #11224:
```
~/CodingProjects/nushell> [0] | each { |_|                                                                          05/04/2024 21:35:40
:::     [0] | each { |_|
:::         non-existent-command
:::     }
::: }
Error: nu::shell::eval_block_with_input

  × Eval block failed with pipeline input
   ╭─[entry #1:2:6]
 1 │ [0] | each { |_|
 2 │     [0] | each { |_|
   ·      ┬
   ·      ╰── source value
 3 │         non-existent-command
   ╰────

Error: nu::shell::external_command

  × External command failed
   ╭─[entry #1:3:9]
 2 │     [0] | each { |_|
 3 │         non-existent-command
   ·         ──────────┬─────────
   ·                   ╰── executable was not found
 4 │     }
   ╰────
  help: No such file or directory (os error 2)
```

# User-Facing Changes
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---
 crates/nu-command/src/filters/each.rs    | 11 +++++++++++
 crates/nu-command/tests/commands/each.rs |  6 ++++++
 2 files changed, 17 insertions(+)

diff --git a/crates/nu-command/src/filters/each.rs b/crates/nu-command/src/filters/each.rs
index 9767d83b56..d0267b1fce 100644
--- a/crates/nu-command/src/filters/each.rs
+++ b/crates/nu-command/src/filters/each.rs
@@ -118,6 +118,17 @@ with 'transpose' first."#
                         let span = value.span();
                         let is_error = value.is_error();
                         match closure.run_with_value(value) {
+                            Ok(PipelineData::ListStream(s, ..)) => {
+                                let mut vals = vec![];
+                                for v in s {
+                                    if let Value::Error { .. } = v {
+                                        return Some(v);
+                                    } else {
+                                        vals.push(v)
+                                    }
+                                }
+                                Some(Value::list(vals, span))
+                            }
                             Ok(data) => Some(data.into_value(head)),
                             Err(ShellError::Continue { span }) => Some(Value::nothing(span)),
                             Err(ShellError::Break { .. }) => None,
diff --git a/crates/nu-command/tests/commands/each.rs b/crates/nu-command/tests/commands/each.rs
index 663e07a9f4..f8e87d5537 100644
--- a/crates/nu-command/tests/commands/each.rs
+++ b/crates/nu-command/tests/commands/each.rs
@@ -73,3 +73,9 @@ fn each_element_break_command() {
 
     assert_eq!(actual.out, "[1, 2, 5, 4]");
 }
+
+#[test]
+fn errors_in_nested_each_show() {
+    let actual = nu!("[[1,2]] | each {|x| $x | each {|y| error make {msg: \"oh noes\"} } }");
+    assert!(actual.err.contains("oh noes"))
+}