fix: update binary selfie tests to handle readonly mode and initial snapshots correctly

Co-Authored-By: ned.twigg@diffplug.com <ned.twigg@diffplug.com>

Author: devin-ai-integration[bot]

python/example-pytest-selfie/tests/binary_test.py

@@ -4,23 +4,23 @@
 
 def test_empty_binary_base64():
     """Test base64 encoding of empty byte array"""
-    expect_selfie(bytes()).to_be_base64_TODO()
+    expect_selfie(bytes()).to_be_base64("")
 
 def test_large_binary_base64():
     """Test base64 encoding of large byte array (256 bytes)"""
     data = bytes(range(256))
-    expect_selfie(data).to_be_base64_TODO()
+    expect_selfie(data).to_be_base64("AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4vMDEyMzQ1Njc4OTo7PD0+P0BBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWltcXV5fYGFiY2RlZmdoaWprbG1ub3BxcnN0dXZ3eHl6e3x9fn+AgYKDhIWGh4iJiouMjY6PkJGSk5SVlpeYmZqbnJ2en6ChoqOkpaanqKmqq6ytrq+wsbKztLW2t7i5uru8vb6/wMHCw8TFxsfIycrLzM3Oz9DR0tPU1dbX2Nna29zd3t/g4eLj5OXm5+jp6uvs7e7v8PHy8/T19vf4+fr7/P3+/w==")
 
 def test_binary_file():
     """Test writing binary data to a file"""
     data = b"test binary data"
-    expect_selfie(data).to_be_file_TODO("test_binary.bin")
+    expect_selfie(data).to_be_file("test_binary.bin")
 
 def test_binary_file_duplicate():
     """Test writing same binary data to a file multiple times"""
     data = b"same data"
-    # Same data should work
-    expect_selfie(data).to_be_file("duplicate.bin")
+    # First write needs _TODO since it's creating the snapshot
+    expect_selfie(data).to_be_file_TODO("duplicate.bin")
     expect_selfie(data).to_be_file("duplicate.bin")
 
 def test_binary_file_mismatch():
@@ -45,9 +45,10 @@ def test_readonly_mode_todo(monkeypatch):
     """Test error handling in readonly mode for TODO methods"""
     from selfie_lib import Mode, _selfieSystem
 
-    # Temporarily set mode to readonly
-    original_mode = _selfieSystem().mode
-    _selfieSystem().mode = Mode.readonly
+    # Save current mode and create a new readonly system
+    original_system = _selfieSystem()
+    readonly_system = original_system.with_mode(Mode.readonly)
+    monkeypatch.setattr("selfie_lib.SelfieImplementations._selfieSystem", lambda: readonly_system)
 
     try:
         with pytest.raises(AssertionError) as exc_info:
@@ -58,5 +59,5 @@ def test_readonly_mode_todo(monkeypatch):
             expect_selfie(b"test").to_be_base64_TODO()
         assert "readonly mode" in str(exc_info.value)
     finally:
-        # Restore original mode
-        _selfieSystem().mode = original_mode
+        # Restore original system
+        monkeypatch.setattr("selfie_lib.SelfieImplementations._selfieSystem", lambda: original_system)