fix: resolve CI issues - push complete implementation with tests

tests/test_cli.py

@@ -1,5 +1,3 @@
-"""Tests for the CLI module."""
-
 import sys
 from pathlib import Path
 
@@ -11,17 +9,13 @@ from gdiffer.cli import main
 
 
 class TestCLIMain:
-    """Tests for the main CLI command."""
-
     def test_main_help(self):
-        """Test that --help works."""
         runner = CliRunner()
         result = runner.invoke(main, ["--help"])
         assert result.exit_code == 0
         assert "Git Diff Explainer" in result.output or "diff" in result.output.lower()
 
     def test_main_version(self):
-        """Test that --version works."""
         runner = CliRunner()
         result = runner.invoke(main, ["--version"])
         assert result.exit_code == 0
@@ -29,10 +23,7 @@ class TestCLIMain:
 
 
 class TestExplainCommand:
-    """Tests for the explain command."""
-
     def test_explain_simple_diff(self):
-        """Test explaining a simple diff."""
         diff = """diff --git a/test.py b/test.py
 index 123..456 100644
 --- a/test.py
@@ -49,19 +40,16 @@ index 123..456 100644
         assert "test.py" in result.output or "Files" in result.output
 
     def test_explain_no_input(self):
-        """Test explaining with no input shows error."""
         runner = CliRunner()
         result = runner.invoke(main, ["explain"])
         assert result.exit_code != 0
 
     def test_explain_invalid_diff(self):
-        """Test explaining an invalid diff."""
         runner = CliRunner()
         result = runner.invoke(main, ["explain", "not a valid diff"])
         assert result.exit_code != 0
 
     def test_explain_json_format(self):
-        """Test explaining in JSON format."""
         diff = """diff --git a/test.py b/test.py
 new file mode 100644
 --- /dev/null
@@ -75,7 +63,6 @@ new file mode 100644
         assert "{" in result.output
 
     def test_explain_plain_format(self):
-        """Test explaining in plain text format."""
         diff = """diff --git a/test.py b/test.py
 --- a/test.py
 +++ b/test.py
@@ -89,10 +76,7 @@ new file mode 100644
 
 
 class TestIssuesCommand:
-    """Tests for the issues command."""
-
     def test_issues_with_security_issue(self):
-        """Test detecting security issues."""
         diff = """diff --git a/db.py b/db.py
 --- a/db.py
 +++ b/db.py
@@ -107,10 +91,7 @@ class TestIssuesCommand:
 
 
 class TestSummarizeCommand:
-    """Tests for the summarize command."""
-
     def test_summarize_simple_diff(self):
-        """Test summarizing a simple diff."""
         diff = """diff --git a/test.py b/test.py
 --- a/test.py
 +++ b/test.py
@@ -124,7 +105,6 @@ class TestSummarizeCommand:
         assert "Files" in result.output or "changed" in result.output.lower()
 
     def test_summarize_multi_file(self):
-        """Test summarizing multi-file diff."""
         diff = """diff --git a/file1.py b/file1.py
 new file mode 100644
 --- /dev/null
@@ -145,10 +125,7 @@ deleted file mode 100644
 
 
 class TestCLIOptions:
-    """Tests for CLI options."""
-
     def test_verbose_option(self):
-        """Test verbose output option."""
         diff = """diff --git a/test.py b/test.py
 --- a/test.py
 +++ b/test.py
@@ -161,7 +138,6 @@ class TestCLIOptions:
         assert result.exit_code == 0
 
     def test_output_format_option(self):
-        """Test output format option."""
         diff = """diff --git a/test.py b/test.py
 --- a/test.py
 +++ b/test.py