ref: Some ruff fixes from preview (#5420)

* Some ruff fixes from preview

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 2/3)

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/utils/test_image_utils.py

@@ -16,51 +16,57 @@ def sample_image(tmp_path):
     return image_path
 
 
-class TestImageUtils:
-    def test_convert_image_to_base64_success(self, sample_image):
-        """Test successful conversion of image to base64."""
-        base64_str = convert_image_to_base64(sample_image)
-        assert isinstance(base64_str, str)
-        # Verify it's valid base64
-        assert base64.b64decode(base64_str)
+def test_convert_image_to_base64_success(sample_image):
+    """Test successful conversion of image to base64."""
+    base64_str = convert_image_to_base64(sample_image)
+    assert isinstance(base64_str, str)
+    # Verify it's valid base64
+    assert base64.b64decode(base64_str)
 
-    def test_convert_image_to_base64_empty_path(self):
-        """Test conversion with empty path."""
-        with pytest.raises(ValueError, match="Image path cannot be empty"):
-            convert_image_to_base64("")
 
-    def test_convert_image_to_base64_nonexistent_file(self):
-        """Test conversion with non-existent file."""
-        with pytest.raises(FileNotFoundError, match="Image file not found"):
-            convert_image_to_base64("nonexistent.png")
+def test_convert_image_to_base64_empty_path():
+    """Test conversion with empty path."""
+    with pytest.raises(ValueError, match="Image path cannot be empty"):
+        convert_image_to_base64("")
 
-    def test_convert_image_to_base64_directory(self, tmp_path):
-        """Test conversion with directory path instead of file."""
-        with pytest.raises(ValueError, match="Path is not a file"):
-            convert_image_to_base64(tmp_path)
 
-    def test_create_data_url_success(self, sample_image):
-        """Test successful creation of data URL."""
-        data_url = create_data_url(sample_image)
-        assert data_url.startswith("data:image/png;base64,")
-        # Verify the base64 part is valid
-        base64_part = data_url.split(",")[1]
-        assert base64.b64decode(base64_part)
+def test_convert_image_to_base64_nonexistent_file():
+    """Test conversion with non-existent file."""
+    with pytest.raises(FileNotFoundError, match="Image file not found"):
+        convert_image_to_base64("nonexistent.png")
 
-    def test_create_data_url_with_custom_mime(self, sample_image):
-        """Test creation of data URL with custom MIME type."""
-        custom_mime = "image/custom"
-        data_url = create_data_url(sample_image, mime_type=custom_mime)
-        assert data_url.startswith(f"data:{custom_mime};base64,")
 
-    def test_create_data_url_invalid_file(self):
-        """Test creation of data URL with invalid file."""
-        with pytest.raises(FileNotFoundError):
-            create_data_url("nonexistent.jpg")
+def test_convert_image_to_base64_directory(tmp_path):
+    """Test conversion with directory path instead of file."""
+    with pytest.raises(ValueError, match="Path is not a file"):
+        convert_image_to_base64(tmp_path)
 
-    def test_create_data_url_unrecognized_extension(self, tmp_path):
-        """Test creation of data URL with unrecognized file extension."""
-        invalid_file = tmp_path / "test.unknown"
-        invalid_file.touch()
-        with pytest.raises(ValueError, match="Could not determine MIME type"):
-            create_data_url(invalid_file)
+
+def test_create_data_url_success(sample_image):
+    """Test successful creation of data URL."""
+    data_url = create_data_url(sample_image)
+    assert data_url.startswith("data:image/png;base64,")
+    # Verify the base64 part is valid
+    base64_part = data_url.split(",")[1]
+    assert base64.b64decode(base64_part)
+
+
+def test_create_data_url_with_custom_mime(sample_image):
+    """Test creation of data URL with custom MIME type."""
+    custom_mime = "image/custom"
+    data_url = create_data_url(sample_image, mime_type=custom_mime)
+    assert data_url.startswith(f"data:{custom_mime};base64,")
+
+
+def test_create_data_url_invalid_file():
+    """Test creation of data URL with invalid file."""
+    with pytest.raises(FileNotFoundError):
+        create_data_url("nonexistent.jpg")
+
+
+def test_create_data_url_unrecognized_extension(tmp_path):
+    """Test creation of data URL with unrecognized file extension."""
+    invalid_file = tmp_path / "test.unknown"
+    invalid_file.touch()
+    with pytest.raises(ValueError, match="Could not determine MIME type"):
+        create_data_url(invalid_file)

src/backend/tests/unit/utils/test_truncate_long_strings.py

@@ -1,6 +1,7 @@
 import math
 
 import pytest
+from langflow.utils.constants import MAX_TEXT_LENGTH
 from langflow.utils.util_strings import truncate_long_strings
 
 
@@ -48,8 +49,6 @@ def test_truncate_long_strings_negative_max_length():
 
 # Test for None max_length (should use default MAX_TEXT_LENGTH)
 def test_truncate_long_strings_none_max_length():
-    from langflow.utils.constants import MAX_TEXT_LENGTH
-
     long_string = "a" * (MAX_TEXT_LENGTH + 10)
     result = truncate_long_strings(long_string, None)
     assert len(result) == MAX_TEXT_LENGTH + 3  # +3 for "..."