Allow `:move` command to accept directories as target (#13922)

Co-authored-by: Martin Below <martin@below.cologne>

helix-term/src/commands/typed.rs

@@ -2463,7 +2463,16 @@ fn move_buffer(cx: &mut compositor::Context, args: Args, event: PromptEvent) ->
         .path()
         .context("Scratch buffer cannot be moved. Use :write instead")?
         .clone();
-    let new_path = args.first().unwrap().to_string();
+    let new_path: PathBuf = args.first().unwrap().into();
+
+    // if new_path is a directory, append the original file name
+    // to move the file into that directory.
+    let new_path = old_path
+        .file_name()
+        .filter(|_| new_path.is_dir())
+        .map(|old_file_name| new_path.join(old_file_name))
+        .unwrap_or(new_path);
+
     if let Err(err) = cx.editor.move_path(&old_path, new_path.as_ref()) {
         bail!("Could not move file: {err}");
     }

helix-term/tests/test/commands/write.rs

@@ -772,3 +772,70 @@ async fn edit_file_with_content(file_content: &[u8]) -> anyhow::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_move_file_when_given_dir_and_filename() -> anyhow::Result<()> {
+    let dir = tempfile::tempdir()?;
+    let source_file = tempfile::NamedTempFile::new_in(&dir)?;
+    let target_file = dir.path().join("new_name.ext");
+
+    let mut app = helpers::AppBuilder::new()
+        .with_file(source_file.path(), None)
+        .build()?;
+
+    test_key_sequence(
+        &mut app,
+        Some(format!(":move {}<ret>", target_file.to_string_lossy()).as_ref()),
+        None,
+        false,
+    )
+    .await?;
+
+    assert!(
+        target_file.is_file(),
+        "target file '{}' should have been created",
+        target_file.display()
+    );
+    assert!(
+        !source_file.path().exists(),
+        "Source file '{}' should have been removed",
+        source_file.path().display()
+    );
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_move_file_when_given_dir_only() -> anyhow::Result<()> {
+    let source_dir = tempfile::tempdir()?;
+    let target_dir = tempfile::tempdir()?;
+    let source_file = source_dir.path().join("file.ext");
+    std::fs::File::create(&source_file)?;
+
+    let mut app = helpers::AppBuilder::new()
+        .with_file(&source_file, None)
+        .build()?;
+
+    test_key_sequence(
+        &mut app,
+        Some(format!(":move {}<ret>", target_dir.path().to_string_lossy()).as_ref()),
+        None,
+        false,
+    )
+    .await?;
+
+    let target_file = target_dir.path().join("file.ext");
+
+    assert!(
+        target_file.is_file(),
+        "target file '{}' should have been created",
+        target_file.display()
+    );
+    assert!(
+        !source_file.exists(),
+        "Source file '{}' should have been removed",
+        source_file.display()
+    );
+
+    Ok(())
+}