From fb197f562a778b687822a15b7e9374713324a5bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Braulio=20Valdivielso=20Mart=C3=ADnez?=
 <brlvldvlsmrtnz@gmail.com>
Date: Fri, 26 Nov 2021 18:27:41 +0000
Subject: [PATCH] save --append: create file if it doesn't exist (#4156)

* have save --append create file if not exists

Currently, doing:

echo a | save --raw --append file.txt

will fail if file.txt does not exist. This PR changes that

* test that `save --append` will create new file
---
 crates/nu-command/tests/commands/save.rs       | 18 ++++++++++++++++++
 .../src/filesystem/filesystem_shell.rs         |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/crates/nu-command/tests/commands/save.rs b/crates/nu-command/tests/commands/save.rs
index 70eb3937bf..ff953bcfb6 100644
--- a/crates/nu-command/tests/commands/save.rs
+++ b/crates/nu-command/tests/commands/save.rs
@@ -47,3 +47,21 @@ fn writes_out_csv() {
         assert!(actual.contains("nu,0.14,A new type of shell,MIT,2018"));
     })
 }
+
+#[test]
+fn save_append_will_create_file_if_not_exists() {
+    Playground::setup("save_test_3", |dirs, sandbox| {
+        sandbox.with_files(vec![]);
+
+        let expected_file = dirs.test().join("new-file.txt");
+
+        nu!(
+            cwd: dirs.root(),
+            r#"echo hello | save --raw --append save_test_3/new-file.txt"#,
+        );
+
+        let actual = file_contents(expected_file);
+        println!("{}", actual);
+        assert!(actual == "hello");
+    })
+}
diff --git a/crates/nu-engine/src/filesystem/filesystem_shell.rs b/crates/nu-engine/src/filesystem/filesystem_shell.rs
index 1f74919c1b..1967d99c9f 100644
--- a/crates/nu-engine/src/filesystem/filesystem_shell.rs
+++ b/crates/nu-engine/src/filesystem/filesystem_shell.rs
@@ -884,7 +884,7 @@ impl Shell for FilesystemShell {
     ) -> Result<OutputStream, ShellError> {
         let mut options = OpenOptions::new();
         if append {
-            options.append(true)
+            options.append(true).create(true)
         } else {
             options.write(true).create(true).truncate(true)
         };