feat(gitlab_glab): add diff content filtering to get_mr_diff

- Add filter_diff_content method to filter out unwanted file extensions
- Default filtering excludes .lock and .log files to reduce noise
- Smart lock file detection handles package-lock.json, yarn.lock, etc.
- Customizable filtering via filter_extensions parameter
- Filtering can be disabled by passing empty list
- Add comprehensive tests for all filtering scenarios
- Update README.md with filtering documentation
- Maintain backward compatibility with existing API

1 files changed, 287 insertions, 0 deletions

diff --git a/servers/gitlab_glab/tests/test_server.py b/servers/gitlab_glab/tests/test_server.py
index 867b2c0..13f90af 100644
--- a/servers/gitlab_glab/tests/test_server.py
+++ b/servers/gitlab_glab/tests/test_server.py
@@ -1020,3 +1020,290 @@ index 1234567..abcdefg 100644
             ["ci", "run"],
             working_dir,
         )
+
+    @patch.object(GitLabServer, "execute_glab_command")
+    def test_get_mr_diff_with_default_filtering(self, mock_execute: MagicMock) -> None:
+        """Test MR diff with default filtering (.lock and .log files)."""
+        # Mock diff content with .lock and .log files
+        diff_content = """diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,3 +1,4 @@
+ {
+   "name": "test",
++  "version": "1.0.0",
+   "lockfileVersion": 1
+}
+diff --git a/debug.log b/debug.log
+index 1234567..abcdefg 100644
+--- a/debug.log
++++ b/debug.log
+@@ -1,2 +1,3 @@
+ [INFO] Starting application
++[INFO] Loading configuration
+ [INFO] Application ready
+diff --git a/src/main.py b/src/main.py
+index 1234567..abcdefg 100644
+--- a/src/main.py
++++ b/src/main.py
+@@ -1,3 +1,4 @@
+ def main():
+     print("Hello")
++    print("World")
+     return 0"""
+        mock_execute.return_value = (True, diff_content)
+
+        server = GitLabServer()
+        working_dir = "/test/directory"
+        result = server.get_mr_diff(working_directory=working_dir)
+
+        # Check that .lock and .log files are filtered out
+        filtered_diff = result["diff"]
+        assert "package-lock.json" not in filtered_diff
+        assert "debug.log" not in filtered_diff
+        assert "src/main.py" in filtered_diff
+        assert 'print("World")' in filtered_diff
+
+    @patch.object(GitLabServer, "execute_glab_command")
+    def test_get_mr_diff_with_custom_filtering(self, mock_execute: MagicMock) -> None:
+        """Test MR diff with custom filtering extensions."""
+        # Mock diff content with various file types
+        diff_content = """diff --git a/test.txt b/test.txt
+index 1234567..abcdefg 100644
+--- a/test.txt
++++ b/test.txt
+@@ -1,2 +1,3 @@
+ line 1
++new line
+ line 2
+diff --git a/config.json b/config.json
+index 1234567..abcdefg 100644
+--- a/config.json
++++ b/config.json
+@@ -1,3 +1,4 @@
+ {
+   "setting": "value"
++  "new_setting": "new_value"
+ }
+diff --git a/temp.tmp b/temp.tmp
+index 1234567..abcdefg 100644
+--- a/temp.tmp
++++ b/temp.tmp
+@@ -1,2 +1,3 @@
+ temp data
++more temp data
+ end"""
+        mock_execute.return_value = (True, diff_content)
+
+        server = GitLabServer()
+        working_dir = "/test/directory"
+        result = server.get_mr_diff(
+            working_directory=working_dir,
+            filter_extensions=[".tmp", ".json"]
+        )
+
+        # Check that .tmp and .json files are filtered out
+        filtered_diff = result["diff"]
+        assert "temp.tmp" not in filtered_diff
+        assert "config.json" not in filtered_diff
+        assert "test.txt" in filtered_diff
+        assert "new line" in filtered_diff
+
+    @patch.object(GitLabServer, "execute_glab_command")
+    def test_get_mr_diff_with_no_filtering(self, mock_execute: MagicMock) -> None:
+        """Test MR diff with filtering disabled (empty list)."""
+        # Mock diff content with .lock file
+        diff_content = """diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,3 +1,4 @@
+ {
+   "name": "test",
++  "version": "1.0.0",
+   "lockfileVersion": 1
+}"""
+        mock_execute.return_value = (True, diff_content)
+
+        server = GitLabServer()
+        working_dir = "/test/directory"
+        result = server.get_mr_diff(
+            working_directory=working_dir,
+            filter_extensions=[]
+        )
+
+        # Check that no filtering occurred
+        filtered_diff = result["diff"]
+        assert "package-lock.json" in filtered_diff
+        assert '"version": "1.0.0"' in filtered_diff
+
+    def test_filter_diff_content_basic(self) -> None:
+        """Test basic diff content filtering."""
+        server = GitLabServer()
+        
+        diff_content = """diff --git a/src/main.py b/src/main.py
+index 1234567..abcdefg 100644
+--- a/src/main.py
++++ b/src/main.py
+@@ -1,3 +1,4 @@
+ def main():
+     print("Hello")
++    print("World")
+     return 0
+diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,3 +1,4 @@
+ {
+   "name": "test",
++  "version": "1.0.0",
+   "lockfileVersion": 1
+}"""
+
+        filtered = server.filter_diff_content(diff_content, [".lock"])
+        
+        assert "src/main.py" in filtered
+        assert 'print("World")' in filtered
+        assert "package-lock.json" not in filtered
+        assert '"version": "1.0.0"' not in filtered
+
+    def test_filter_diff_content_multiple_extensions(self) -> None:
+        """Test filtering with multiple extensions."""
+        server = GitLabServer()
+        
+        diff_content = """diff --git a/app.py b/app.py
+index 1234567..abcdefg 100644
+--- a/app.py
++++ b/app.py
+@@ -1,2 +1,3 @@
+ import logging
++logging.basicConfig()
+ app = Flask(__name__)
+diff --git a/debug.log b/debug.log
+index 1234567..abcdefg 100644
+--- a/debug.log
++++ b/debug.log
+@@ -1,2 +1,3 @@
+ [INFO] Starting
++[DEBUG] Debug message
+ [INFO] Ready
+diff --git a/yarn.lock b/yarn.lock
+index 1234567..abcdefg 100644
+--- a/yarn.lock
++++ b/yarn.lock
+@@ -1,3 +1,4 @@
+ # THIS IS AN AUTOGENERATED FILE
++# Dependencies
+ package@1.0.0:
+   version "1.0.0"""
+
+        filtered = server.filter_diff_content(diff_content, [".log", ".lock"])
+        
+        assert "app.py" in filtered
+        assert "logging.basicConfig()" in filtered
+        assert "debug.log" not in filtered
+        assert "yarn.lock" not in filtered
+        assert "[DEBUG] Debug message" not in filtered
+        assert "# Dependencies" not in filtered
+
+    def test_filter_diff_content_empty_extensions(self) -> None:
+        """Test filtering with empty extensions list."""
+        server = GitLabServer()
+        
+        diff_content = """diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,2 +1,3 @@
+ {
++  "name": "test",
+   "lockfileVersion": 1
+}"""
+
+        filtered = server.filter_diff_content(diff_content, [])
+        
+        # Should return original content when no extensions to filter
+        assert filtered == diff_content
+
+    def test_filter_diff_content_malformed_diff_header(self) -> None:
+        """Test filtering with malformed diff headers."""
+        server = GitLabServer()
+        
+        diff_content = """diff --git a/file.py
+index 1234567..abcdefg 100644
+--- a/file.py
++++ b/file.py
+@@ -1,2 +1,3 @@
+ line 1
++new line
+ line 2
+diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,2 +1,3 @@
+ {
++  "version": "1.0.0",
+   "lockfileVersion": 1
+}"""
+
+        filtered = server.filter_diff_content(diff_content, [".lock"])
+        
+        # Malformed header should not be filtered
+        assert "diff --git a/file.py" in filtered
+        assert "new line" in filtered
+        # Properly formed header with .lock extension should be filtered
+        assert "package-lock.json" not in filtered
+        assert '"version": "1.0.0"' not in filtered
+
+    @patch.object(GitLabServer, "execute_glab_command")
+    def test_get_mr_diff_filtering_with_large_file(self, mock_execute: MagicMock) -> None:
+        """Test that filtering works correctly even when creating temp files."""
+        # Create a large diff that will still be large after filtering
+        large_diff_base = """diff --git a/src/main.py b/src/main.py
+index 1234567..abcdefg 100644
+--- a/src/main.py
++++ b/src/main.py
+@@ -1,3 +1,4 @@
+ def main():
+     print("Hello")
++    print("World")
+     return 0
+"""
+        # Add a lot of content to main.py to make it large
+        large_diff = large_diff_base + "+    # " + "Large comment line\n" * 3000
+        
+        # Add package-lock.json content that should be filtered out
+        large_diff += """diff --git a/package-lock.json b/package-lock.json
+index 1234567..abcdefg 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,500 +1,501 @@
+ {
+   "name": "test",
++  "version": "1.0.0",
+""" + "  \"dependency\": \"^1.0.0\",\n" * 1000 + "}\n"
+        
+        mock_execute.return_value = (True, large_diff)
+
+        server = GitLabServer()
+        working_dir = "/test/directory"
+        
+        with patch("tempfile.NamedTemporaryFile") as mock_temp:
+            mock_file = MagicMock()
+            mock_file.name = "/tmp/test_diff.diff"
+            mock_temp.return_value.__enter__.return_value = mock_file
+            
+            result = server.get_mr_diff(
+                working_directory=working_dir,
+                max_size_kb=1  # Force temp file creation
+            )
+
+            # Should still filter before saving to temp file
+            assert result["diff_too_large"] is True
+            # The filtered content should be written to temp file
+            written_content = mock_file.write.call_args[0][0]
+            assert "src/main.py" in written_content
+            assert "package-lock.json" not in written_content