From 1ba5094492a647b6b0290bbbed60c1b8bf4f6782 Mon Sep 17 00:00:00 2001
From: Victor Nilsson <vicnilss@student.chalmers.se>
Date: Fri, 10 Feb 2023 15:14:59 +0100
Subject: [PATCH] fix!: add newline at the end of formatted notebooks (#36)

Fixes #37 and closes #38.

BREAKING CHANGE: All notebooks will now have a newline character `\n` at the end of the file.
---
 blackbricks/blackbricks.py |  2 +-
 blackbricks/cli.py         |  1 -
 blackbricks/files.py       | 26 +++++++++++++++++++++++---
 test_notebooks/test.py     |  2 +-
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/blackbricks/blackbricks.py b/blackbricks/blackbricks.py
index 89b97a3..8ae6f8c 100644
--- a/blackbricks/blackbricks.py
+++ b/blackbricks/blackbricks.py
@@ -72,7 +72,7 @@ def format_str(content: str, config: FormatConfig = FormatConfig()) -> str:
 
         output_ws_normalized += line + "\n"
 
-    return output_ws_normalized.strip()
+    return output_ws_normalized.strip() + "\n"
 
 
 def _format_sql_cell(
diff --git a/blackbricks/cli.py b/blackbricks/cli.py
index 7e17cd7..778cd83 100644
--- a/blackbricks/cli.py
+++ b/blackbricks/cli.py
@@ -31,7 +31,6 @@ def process_files(
     n_notebooks = 0
 
     for file_ in files:
-
         try:
             content = file_.content
         except UnicodeDecodeError:
diff --git a/blackbricks/files.py b/blackbricks/files.py
index 694aaef..48490d9 100644
--- a/blackbricks/files.py
+++ b/blackbricks/files.py
@@ -42,10 +42,32 @@ class RemoteNotebook(File):
 
     @property
     def content(self) -> str:
-        return self.api_client.read_notebook(self.path)
+        """
+        Get the content of the notebook as a string.
+
+        Note: Databricks will not include a trailing newlines from a notebook.
+        That is, even if you checkout a notebook from a repo where there is a trailing
+        newline, Databricks won't "show" an empty line in the UI. And similarly, this
+        API doesn't include it. This contrasts with the prefered style of terminating
+        the files with a newline, as enforced by black and blackbricks. To avoid
+        perpetually reporting diffs due to newlines, we add a trailing newline to the
+        content, _assuming_ that the
+        we assume it to be present and add it back if it is missing. Failing to do this
+        will cause blackbricks to perpetually report that it wants to add a trailing
+        newline to remote notebooks.
+        """
+        return self.api_client.read_notebook(self.path) + "\n"
 
     @content.setter
     def content(self, new_content: str, /) -> None:
+        """
+        Set the content of the notebook to the given string.
+
+        Note: We do _not_ need to do the inverse handling of trailing newlines as in
+        the getter. The new content here is presumably the output of blackbricks, and
+        we should let Databricks import that from the same source as it would find by
+        checking out a repo notebook that has been formatted with blackbricks.
+        """
         self.api_client.write_notebook(self.path, new_content)
 
 
@@ -71,12 +93,10 @@ def resolve_filepaths(paths: List[str]) -> List[str]:
             raise typer.Exit(1)
 
         if os.path.isdir(path):
-
             # Recursively  add all the files/dirs in path to the paths to be consumed.
             paths.extend([os.path.join(path, f) for f in os.listdir(path)])
 
         else:
-
             file_paths.append(path)
 
     return file_paths
diff --git a/test_notebooks/test.py b/test_notebooks/test.py
index e8380ed..d1877dd 100644
--- a/test_notebooks/test.py
+++ b/test_notebooks/test.py
@@ -78,4 +78,4 @@ def test_func(input_param):
 # MAGIC %sql
 # MAGIC SELECT id
 # MAGIC FROM test_table
-# MAGIC LIMIT 1
\ No newline at end of file
+# MAGIC LIMIT 1