chore: filecmp add unittest

Author: fatelei

Lib/test/test_filecmp.py

@@ -2,6 +2,7 @@
 import os
 import re
 import shutil
+import sys
 import tempfile
 import unittest
 
@@ -367,5 +368,212 @@ def _assert_report(self, dircmp_report, expected_report_lines):
             self.assertEqual(report_lines, expected_report_lines)
 
 
+class TestFilecmpCLI(unittest.TestCase):
+    """Test the command line interface of filecmp module"""
+    
+    def setUp(self):
+        self.temp_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self.temp_dir)
+        
+        # Create test directories and files
+        self.dir1 = os.path.join(self.temp_dir, 'dir1')
+        self.dir2 = os.path.join(self.temp_dir, 'dir2')
+        os.makedirs(self.dir1)
+        os.makedirs(self.dir2)
+        
+        # Create identical files
+        with open(os.path.join(self.dir1, 'same.txt'), 'w') as f:
+            f.write('same content')
+        with open(os.path.join(self.dir2, 'same.txt'), 'w') as f:
+            f.write('same content')
+            
+        # Create different files
+        with open(os.path.join(self.dir1, 'different.txt'), 'w') as f:
+            f.write('content in dir1')
+        with open(os.path.join(self.dir2, 'different.txt'), 'w') as f:
+            f.write('content in dir2')
+            
+        # Create file only in dir1
+        with open(os.path.join(self.dir1, 'only_in_dir1.txt'), 'w') as f:
+            f.write('unique to dir1')
+            
+        # Create file only in dir2
+        with open(os.path.join(self.dir2, 'only_in_dir2.txt'), 'w') as f:
+            f.write('unique to dir2')
+            
+        # Create subdirectories for recursive testing
+        self.subdir1 = os.path.join(self.dir1, 'subdir')
+        self.subdir2 = os.path.join(self.dir2, 'subdir')
+        os.makedirs(self.subdir1)
+        os.makedirs(self.subdir2)
+        
+        with open(os.path.join(self.subdir1, 'subfile.txt'), 'w') as f:
+            f.write('sub content')
+        with open(os.path.join(self.subdir2, 'subfile.txt'), 'w') as f:
+            f.write('different sub content')
+
+    def test_demo_basic_comparison(self):
+        """Test basic directory comparison via demo()"""
+        import sys
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', self.dir1, self.dir2]
+            with support.captured_stdout() as stdout:
+                filecmp.__dict__['demo']()
+                output = stdout.getvalue()
+            
+            # Check that output contains expected comparison results
+            self.assertIn('diff', output)
+            self.assertIn('same.txt', output)
+            self.assertIn('different.txt', output)
+            self.assertIn('only_in_dir1.txt', output)
+            self.assertIn('only_in_dir2.txt', output)
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_recursive_comparison(self):
+        """Test recursive directory comparison via demo() with -r flag"""
+        import sys
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', '-r', self.dir1, self.dir2]
+            with support.captured_stdout() as stdout:
+                filecmp.__dict__['demo']()
+                output = stdout.getvalue()
+            
+            # Check that output contains subdirectory comparison
+            self.assertIn('subdir', output)
+            self.assertIn('subfile.txt', output)
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_long_flag(self):
+        """Test demo with long --recursive flag (should fail as only -r is supported)"""
+        import sys
+        import getopt
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', '--recursive', self.dir1, self.dir2]
+            with self.assertRaises(getopt.GetoptError):
+                filecmp.__dict__['demo']()
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_no_arguments(self):
+        """Test demo with no arguments (should raise GetoptError)"""
+        import sys
+        import getopt
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp']
+            with self.assertRaises(getopt.GetoptError) as cm:
+                filecmp.__dict__['demo']()
+            self.assertIn('need exactly two args', str(cm.exception))
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_one_argument(self):
+        """Test demo with only one directory argument (should raise GetoptError)"""
+        import sys
+        import getopt
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', self.dir1]
+            with self.assertRaises(getopt.GetoptError) as cm:
+                filecmp.__dict__['demo']()
+            self.assertIn('need exactly two args', str(cm.exception))
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_three_arguments(self):
+        """Test demo with three arguments (should raise GetoptError)"""
+        import sys
+        import getopt
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', self.dir1, self.dir2, 'extra']
+            with self.assertRaises(getopt.GetoptError) as cm:
+                filecmp.__dict__['demo']()
+            self.assertIn('need exactly two args', str(cm.exception))
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_nonexistent_directory(self):
+        """Test demo with nonexistent directory"""
+        import sys
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', self.dir1, '/nonexistent/path']
+            # This should raise an exception during comparison
+            with self.assertRaises((FileNotFoundError, OSError)):
+                filecmp.__dict__['demo']()
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_identical_directories(self):
+        """Test demo with identical directories"""
+        import sys
+        
+        dir3 = os.path.join(self.temp_dir, 'dir3')
+        dir4 = os.path.join(self.temp_dir, 'dir4')
+        os.makedirs(dir3)
+        os.makedirs(dir4)
+        
+        with open(os.path.join(dir3, 'file1.txt'), 'w') as f:
+            f.write('same content')
+        with open(os.path.join(dir4, 'file1.txt'), 'w') as f:
+            f.write('same content')
+            
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', dir3, dir4]
+            with support.captured_stdout() as stdout:
+                filecmp.__dict__['demo']()
+                output = stdout.getvalue()
+            
+            # Should indicate identical files
+            self.assertIn('Identical files', output)
+            self.assertIn('file1.txt', output)
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_empty_directories(self):
+        """Test demo with empty directories"""
+        import sys
+        
+        dir3 = os.path.join(self.temp_dir, 'empty1')
+        dir4 = os.path.join(self.temp_dir, 'empty2')
+        os.makedirs(dir3)
+        os.makedirs(dir4)
+        
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', dir3, dir4]
+            with support.captured_stdout() as stdout:
+                filecmp.__dict__['demo']()
+                output = stdout.getvalue()
+            
+            # Should handle empty directories gracefully
+            self.assertTrue(len(output) > 0)
+        finally:
+            sys.argv = old_argv
+
+    def test_demo_with_files_instead_of_directories(self):
+        """Test demo when file paths are given instead of directories"""
+        import sys
+        
+        file1 = os.path.join(self.dir1, 'same.txt')
+        file2 = os.path.join(self.dir2, 'same.txt')
+        
+        old_argv = sys.argv
+        try:
+            sys.argv = ['filecmp', file1, file2]
+            # This should raise an exception as files are not directories
+            with self.assertRaises((NotADirectoryError, OSError)):
+                filecmp.__dict__['demo']()
+        finally:
+            sys.argv = old_argv
+
+
 if __name__ == "__main__":
     unittest.main()