Add `insert-final-newline` config option (#8157)

Co-authored-by: Xalfer <64538944+Xalfer@users.noreply.github.com>

3 files changed, 126 insertions, 7 deletions

diff --git a/helix-term/tests/test/commands/write.rs b/helix-term/tests/test/commands/write.rs
index f33c8aaf..376ba5e7 100644
--- a/helix-term/tests/test/commands/write.rs
+++ b/helix-term/tests/test/commands/write.rs
@@ -93,7 +93,7 @@ async fn test_buffer_close_concurrent() -> anyhow::Result<()> {
     )
     .await?;
 
-    helpers::assert_file_has_content(file.as_file_mut(), &RANGE.end().to_string())?;
+    helpers::assert_file_has_content(file.as_file_mut(), &platform_line(&RANGE.end().to_string()))?;
 
     Ok(())
 }
@@ -209,7 +209,7 @@ async fn test_write_concurrent() -> anyhow::Result<()> {
 
     let mut file_content = String::new();
     file.as_file_mut().read_to_string(&mut file_content)?;
-    assert_eq!(RANGE.end().to_string(), file_content);
+    assert_eq!(platform_line(&RANGE.end().to_string()), file_content);
 
     Ok(())
 }
@@ -424,13 +424,132 @@ async fn test_write_utf_bom_file() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn test_write_insert_final_newline_added_if_missing() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .with_input_text("#[h|]#ave you tried chamomile tea?")
+        .build()?;
+
+    test_key_sequence(&mut app, Some(":w<ret>"), None, false).await?;
+
+    helpers::assert_file_has_content(
+        file.as_file_mut(),
+        &helpers::platform_line("have you tried chamomile tea?\n"),
+    )?;
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_write_insert_final_newline_unchanged_if_not_missing() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .with_input_text(&helpers::platform_line("#[t|]#en minutes, please\n"))
+        .build()?;
+
+    test_key_sequence(&mut app, Some(":w<ret>"), None, false).await?;
+
+    helpers::assert_file_has_content(
+        file.as_file_mut(),
+        &helpers::platform_line("ten minutes, please\n"),
+    )?;
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_write_insert_final_newline_unchanged_if_missing_and_false() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_config(Config {
+            editor: helix_view::editor::Config {
+                insert_final_newline: false,
+                ..Default::default()
+            },
+            ..Default::default()
+        })
+        .with_file(file.path(), None)
+        .with_input_text("#[t|]#he quiet rain continued through the night")
+        .build()?;
+
+    test_key_sequence(&mut app, Some(":w<ret>"), None, false).await?;
+
+    helpers::assert_file_has_content(
+        file.as_file_mut(),
+        "the quiet rain continued through the night",
+    )?;
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_write_all_insert_final_newline_add_if_missing_and_modified() -> anyhow::Result<()> {
+    let mut file1 = tempfile::NamedTempFile::new()?;
+    let mut file2 = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file1.path(), None)
+        .with_input_text("#[w|]#e don't serve time travelers here")
+        .build()?;
+
+    test_key_sequence(
+        &mut app,
+        Some(&format!(
+            ":o {}<ret>ia time traveler walks into a bar<esc>:wa<ret>",
+            file2.path().to_string_lossy()
+        )),
+        None,
+        false,
+    )
+    .await?;
+
+    helpers::assert_file_has_content(
+        file1.as_file_mut(),
+        &helpers::platform_line("we don't serve time travelers here\n"),
+    )?;
+
+    helpers::assert_file_has_content(
+        file2.as_file_mut(),
+        &helpers::platform_line("a time traveler walks into a bar\n"),
+    )?;
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_write_all_insert_final_newline_do_not_add_if_unmodified() -> anyhow::Result<()> {
+    let mut file = tempfile::NamedTempFile::new()?;
+    let mut app = helpers::AppBuilder::new()
+        .with_file(file.path(), None)
+        .build()?;
+
+    file.write_all(b"i lost on Jeopardy!")?;
+    file.rewind()?;
+
+    test_key_sequence(&mut app, Some(":wa<ret>"), None, false).await?;
+
+    helpers::assert_file_has_content(file.as_file_mut(), "i lost on Jeopardy!")?;
+
+    Ok(())
+}
+
 async fn edit_file_with_content(file_content: &[u8]) -> anyhow::Result<()> {
     let mut file = tempfile::NamedTempFile::new()?;
 
     file.as_file_mut().write_all(&file_content)?;
 
     helpers::test_key_sequence(
-        &mut helpers::AppBuilder::new().build()?,
+        &mut helpers::AppBuilder::new()
+            .with_config(Config {
+                editor: helix_view::editor::Config {
+                    insert_final_newline: false,
+                    ..Default::default()
+                },
+                ..Default::default()
+            })
+            .build()?,
         Some(&format!(":o {}<ret>:x<ret>", file.path().to_string_lossy())),
         None,
         true,
diff --git a/helix-term/tests/test/helpers.rs b/helix-term/tests/test/helpers.rs
index 6466bc76..e6762baf 100644
--- a/helix-term/tests/test/helpers.rs
+++ b/helix-term/tests/test/helpers.rs
@@ -350,7 +350,7 @@ pub fn assert_file_has_content(file: &mut File, content: &str) -> anyhow::Result
 
     let mut file_content = String::new();
     file.read_to_string(&mut file_content)?;
-    assert_eq!(content, file_content);
+    assert_eq!(file_content, content);
 
     Ok(())
 }
diff --git a/helix-term/tests/test/splits.rs b/helix-term/tests/test/splits.rs
index 1d70f24a..f010c86b 100644
--- a/helix-term/tests/test/splits.rs
+++ b/helix-term/tests/test/splits.rs
@@ -62,9 +62,9 @@ async fn test_split_write_quit_all() -> anyhow::Result<()> {
     )
     .await?;
 
-    helpers::assert_file_has_content(file1.as_file_mut(), "hello1")?;
-    helpers::assert_file_has_content(file2.as_file_mut(), "hello2")?;
-    helpers::assert_file_has_content(file3.as_file_mut(), "hello3")?;
+    helpers::assert_file_has_content(file1.as_file_mut(), &platform_line("hello1"))?;
+    helpers::assert_file_has_content(file2.as_file_mut(), &platform_line("hello2"))?;
+    helpers::assert_file_has_content(file3.as_file_mut(), &platform_line("hello3"))?;
 
     Ok(())
 }