From ba26b30e0b4ed5b7b00a12d0964fc9d68fe08e72 Mon Sep 17 00:00:00 2001
From: EgeKaraismailogluQC
 <128645043+EgeKaraismailogluQC@users.noreply.github.com>
Date: Thu, 21 May 2026 12:50:29 +0200
Subject: [PATCH 1/4] wip

---
 diffly/cli.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/diffly/cli.py b/diffly/cli.py
index 3c5aac2..b2495ac 100644
--- a/diffly/cli.py
+++ b/diffly/cli.py
@@ -120,7 +120,7 @@ def main(
             ),
         ),
     ] = False,
-    hidden_columns: Annotated[
+    hidden_column: Annotated[
         list[str],
         typer.Option(
             help=(
@@ -147,7 +147,7 @@ def main(
         left_name=left_name,
         right_name=right_name,
         slim=slim,
-        hidden_columns=hidden_columns,
+        hidden_columns=hidden_column,
     )
     if output_json:
         typer.echo(summary.to_json())

From 268e0ea570951fd786277dff0f5317ecaf1e2f9e Mon Sep 17 00:00:00 2001
From: EgeKaraismailogluQC
 <128645043+EgeKaraismailogluQC@users.noreply.github.com>
Date: Thu, 21 May 2026 14:08:15 +0200
Subject: [PATCH 2/4] review OB

---
 diffly/cli.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/diffly/cli.py b/diffly/cli.py
index b2495ac..c8e803d 100644
--- a/diffly/cli.py
+++ b/diffly/cli.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 import datetime as dt
+import warnings
 from pathlib import Path
 from typing import Annotated
 
@@ -129,8 +130,18 @@ def main(
             )
         ),
     ] = [],
+    hidden_columns: Annotated[
+        list[str],
+        typer.Option(hidden=True),
+    ] = [],
 ) -> None:
     """Compare two `parquet` files and print the comparison result."""
+    if hidden_columns:
+        warnings.warn(
+            "`--hidden-columns` is deprecated, use `--hidden-column` instead.",
+            FutureWarning,
+        )
+        hidden_column = [*hidden_column, *hidden_columns]
     comparison = compare_frames(
         pl.scan_parquet(left),
         pl.scan_parquet(right),

From 42021b0f7c9f8a2b2ede435db03e1300e896fa34 Mon Sep 17 00:00:00 2001
From: EgeKaraismailogluQC
 <128645043+EgeKaraismailogluQC@users.noreply.github.com>
Date: Thu, 21 May 2026 15:38:24 +0200
Subject: [PATCH 3/4] coverage

---
 tests/cli/test_cli.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tests/cli/test_cli.py b/tests/cli/test_cli.py
index 63926d4..5ab84ea 100644
--- a/tests/cli/test_cli.py
+++ b/tests/cli/test_cli.py
@@ -56,3 +56,26 @@ def test_cli_smoke(tmp_path: Path, output_json: bool) -> None:
         assert result.output == comparison.summary().to_json() + "\n"
     else:
         assert result.output == comparison.summary().format(pretty=True) + "\n"
+
+
+def test_cli_hidden_columns_alias_warns(tmp_path: Path) -> None:
+    left = pl.DataFrame({"id": [1, 2], "secret": ["a", "b"]})
+    right = pl.DataFrame({"id": [1, 2], "secret": ["a", "b"]})
+    left.write_parquet(tmp_path / "left.parquet")
+    right.write_parquet(tmp_path / "right.parquet")
+
+    with pytest.warns(FutureWarning, match="--hidden-columns.*deprecated"):
+        result = runner.invoke(
+            app,
+            [
+                str(tmp_path / "left.parquet"),
+                str(tmp_path / "right.parquet"),
+                "--primary-key",
+                "id",
+                "--hidden-columns",
+                "secret",
+            ],
+            catch_exceptions=False,
+        )
+
+    assert result.exit_code == 0

From da44dc9ab8c2477599e5d23cb268fad07e26db06 Mon Sep 17 00:00:00 2001
From: EgeKaraismailogluQC
 <128645043+EgeKaraismailogluQC@users.noreply.github.com>
Date: Thu, 21 May 2026 15:39:42 +0200
Subject: [PATCH 4/4] coverage

---
 tests/cli/test_cli.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/tests/cli/test_cli.py b/tests/cli/test_cli.py
index 5ab84ea..ccf375b 100644
--- a/tests/cli/test_cli.py
+++ b/tests/cli/test_cli.py
@@ -59,10 +59,9 @@ def test_cli_smoke(tmp_path: Path, output_json: bool) -> None:
 
 
 def test_cli_hidden_columns_alias_warns(tmp_path: Path) -> None:
-    left = pl.DataFrame({"id": [1, 2], "secret": ["a", "b"]})
-    right = pl.DataFrame({"id": [1, 2], "secret": ["a", "b"]})
-    left.write_parquet(tmp_path / "left.parquet")
-    right.write_parquet(tmp_path / "right.parquet")
+    df = pl.DataFrame({"id": [1, 2], "secret": ["a", "b"]})
+    df.write_parquet(tmp_path / "left.parquet")
+    df.write_parquet(tmp_path / "right.parquet")
 
     with pytest.warns(FutureWarning, match="--hidden-columns.*deprecated"):
         result = runner.invoke(