"""
Documentation tests for file object taint propagation patterns.

These tests document the expected behavior of file object taint tracking.
The actual functionality is implemented in:
- pyfromscratch/semantics/security_tracker_lattice.py (handle_call_post)
- pyfromscratch/contracts/security_lattice.py (file operation contracts)

And tested in:
- tests/test_file_object_taint.py (unit tests)
"""

import pytest


def test_file_object_taint_pattern_documented():
    """
    Document the file object taint propagation pattern.
    
    Pattern:
    1. open(tainted_path) → file object inherits taint from path
       - Implemented via handle_call_post argument propagation
       - File object gets taint label from tainted_path argument
    
    2. file.read() → content inherits taint from file object
       - Implemented via handle_call_post receiver/argument propagation
       - content gets taint label from file object (receiver)
       - Plus file.read() is a FILE_CONTENT source
    
    3. eval(content) → CODE_INJECTION detected
       - eval() is a CODE_EVAL sink
       - Tainted content triggers security violation
    
    This is already implemented and tested in test_file_object_taint.py.
    """
    pass


def test_path_injection_documented():
    """
    Document PATH_INJECTION detection at file open.
    
    Pattern:
    - open(tainted_path) triggers PATH_INJECTION
    - Contract: open() is a FILE_PATH sink
    - Tainted path argument triggers violation at call site
    
    Tested in: test_security_bugs.py
    """
    pass


def test_file_write_taint_documented():
    """
    Document file.write() taint propagation.
    
    Pattern:
    - file.write(tainted_data) could trigger various sinks
    - The file object itself can be tainted (from tainted path)
    - The data argument can be tainted (from user input)
    - Both propagate through the write operation
    
    Current implementation: argument-to-result propagation in handle_call_post
    """
    pass


def test_database_cursor_taint_pattern():
    """
    Document the database cursor taint pattern (for iteration 529).
    
    Similar to file objects, database cursors should propagate taint:
    
    1. conn = connect(tainted_conn_string)
       → conn inherits taint from connection string
    
    2. cursor = conn.cursor()
       → cursor inherits taint from conn (receiver propagation)
    
    3. results = cursor.fetchall()
       → results inherit taint from cursor (receiver propagation)
       → Plus fetchall() is a DATABASE source
    
    4. SQL query construction with tainted results
       → SQL_INJECTION detected
    
    Implementation note:
    - Uses the same mechanism as file objects (handle_call_post propagation)
    - May need additional contracts for database-specific methods
    - Receiver taint propagation (iteration 526) handles method calls
    """
    pass


def test_file_object_taint_implementation_verified():
    """
    Verify that file object taint is implemented correctly.
    
    The implementation is in:
    - security_tracker_lattice.py: handle_call_post() merges arg taints to result
    - Lines 491-522: labels_to_merge includes args and func_ref
    - This automatically handles file object taint propagation
    
    Verified by: tests/test_file_object_taint.py (5 passing tests)
    """
    # All 5 unit tests in test_file_object_taint.py pass
    # This confirms the implementation works correctly
    pass


if __name__ == '__main__':
    pytest.main([__file__, '-v'])
