Python: #6501 Increase anthropic chat completion test coverage (#8388)

### Motivation and Context
Increase Anthropic Chat Completion code coverage to 100%
(#6501)

### Description
Match the mocked API responses to realistic examples.

### Contribution Checklist
- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

python/tests/unit/connectors/anthropic/services/test_anthropic_chat_completion.py

@@ -3,6 +3,21 @@
 
 import pytest
 from anthropic import AsyncAnthropic
+from anthropic.lib.streaming import TextEvent
+from anthropic.types import (
+    ContentBlockStopEvent,
+    Message,
+    MessageDeltaUsage,
+    MessageStopEvent,
+    RawContentBlockDeltaEvent,
+    RawContentBlockStartEvent,
+    RawMessageDeltaEvent,
+    RawMessageStartEvent,
+    TextBlock,
+    TextDelta,
+    Usage,
+)
+from anthropic.types.raw_message_delta_event import Delta
 
 from semantic_kernel.connectors.ai.anthropic.prompt_execution_settings.anthropic_prompt_execution_settings import (
     AnthropicChatPromptExecutionSettings,
@@ -12,6 +27,7 @@
 from semantic_kernel.connectors.ai.open_ai.prompt_execution_settings.open_ai_prompt_execution_settings import (
     OpenAIChatPromptExecutionSettings,
 )
+from semantic_kernel.contents.chat_history import ChatHistory
 from semantic_kernel.contents.chat_message_content import ChatMessageContent
 from semantic_kernel.exceptions import ServiceInitializationError, ServiceResponseException
 from semantic_kernel.functions.kernel_arguments import KernelArguments
@@ -26,43 +42,120 @@ def mock_settings() -> AnthropicChatPromptExecutionSettings:
 @pytest.fixture
 def mock_anthropic_client_completion() -> AsyncAnthropic:
     client = MagicMock(spec=AsyncAnthropic)
+
     chat_completion_response = AsyncMock()
-
-    content = [MagicMock(finish_reason="stop", message=MagicMock(role="assistant", content="Test"))]
-    chat_completion_response.content = content
+    chat_completion_response.content = [TextBlock(text="Hello! It's nice to meet you.", type="text")]
+    chat_completion_response.id = "test_id"
+    chat_completion_response.model = "claude-3-opus-20240229"
+    chat_completion_response.role = "assistant"
+    chat_completion_response.stop_reason = "end_turn"
+    chat_completion_response.stop_sequence = None
+    chat_completion_response.type = "message"
+    chat_completion_response.usage = Usage(input_tokens=114, output_tokens=75)
 
     # Create a MagicMock for the messages attribute
     messages_mock = MagicMock()
-    messages_mock.create = chat_completion_response
+    messages_mock.create = AsyncMock(return_value=chat_completion_response)
 
     # Assign the messages_mock to the client.messages attribute
     client.messages = messages_mock
+
     return client
 
 
 @pytest.fixture
 def mock_anthropic_client_completion_stream() -> AsyncAnthropic:
     client = MagicMock(spec=AsyncAnthropic)
-    chat_completion_response = MagicMock()
 
-    content = [
-        MagicMock(finish_reason="stop", delta=MagicMock(role="assistant", content="Test")),
-        MagicMock(finish_reason="stop", delta=MagicMock(role="assistant", content="Test", tool_calls=None)),
+    # Create MagicMock instances for each event with the spec set to the appropriate class
+    mock_raw_message_start_event = MagicMock(spec=RawMessageStartEvent)
+    mock_raw_message_start_event.message = MagicMock(spec=Message)
+    mock_raw_message_start_event.message.id = "test_message_id"
+    mock_raw_message_start_event.message.content = []
+    mock_raw_message_start_event.message.model = "claude-3-opus-20240229"
+    mock_raw_message_start_event.message.role = "assistant"
+    mock_raw_message_start_event.message.stop_reason = None
+    mock_raw_message_start_event.message.stop_sequence = None
+    mock_raw_message_start_event.message.type = "message"
+    mock_raw_message_start_event.message.usage = MagicMock(spec=Usage)
+    mock_raw_message_start_event.message.usage.input_tokens = 41
+    mock_raw_message_start_event.message.usage.output_tokens = 3
+    mock_raw_message_start_event.type = "message_start"
+
+    mock_raw_content_block_start_event = MagicMock(spec=RawContentBlockStartEvent)
+    mock_raw_content_block_start_event.content_block = MagicMock(spec=TextBlock)
+    mock_raw_content_block_start_event.content_block.text = ""
+    mock_raw_content_block_start_event.content_block.type = "text"
+    mock_raw_content_block_start_event.index = 0
+    mock_raw_content_block_start_event.type = "content_block_start"
+
+    mock_raw_content_block_delta_event = MagicMock(spec=RawContentBlockDeltaEvent)
+    mock_raw_content_block_delta_event.delta = MagicMock(spec=TextDelta)
+    mock_raw_content_block_delta_event.delta.text = "Hello! It"
+    mock_raw_content_block_delta_event.delta.type = "text_delta"
+    mock_raw_content_block_delta_event.index = 0
+    mock_raw_content_block_delta_event.type = "content_block_delta"
+
+    mock_text_event = MagicMock(spec=TextEvent)
+    mock_text_event.type = "text"
+    mock_text_event.text = "Hello! It"
+    mock_text_event.snapshot = "Hello! It"
+
+    mock_content_block_stop_event = MagicMock(spec=ContentBlockStopEvent)
+    mock_content_block_stop_event.index = 0
+    mock_content_block_stop_event.type = "content_block_stop"
+    mock_content_block_stop_event.content_block = MagicMock(spec=TextBlock)
+    mock_content_block_stop_event.content_block.text = "Hello! It's nice to meet you."
+    mock_content_block_stop_event.content_block.type = "text"
+
+    mock_raw_message_delta_event = MagicMock(spec=RawMessageDeltaEvent)
+    mock_raw_message_delta_event.delta = MagicMock(spec=Delta)
+    mock_raw_message_delta_event.delta.stop_reason = "end_turn"
+    mock_raw_message_delta_event.delta.stop_sequence = None
+    mock_raw_message_delta_event.type = "message_delta"
+    mock_raw_message_delta_event.usage = MagicMock(spec=MessageDeltaUsage)
+    mock_raw_message_delta_event.usage.output_tokens = 84
+
+    mock_message_stop_event = MagicMock(spec=MessageStopEvent)
+    mock_message_stop_event.type = "message_stop"
+    mock_message_stop_event.message = MagicMock(spec=Message)
+    mock_message_stop_event.message.id = "test_message_stop_id"
+    mock_message_stop_event.message.content = [MagicMock(spec=TextBlock)]
+    mock_message_stop_event.message.content[0].text = "Hello! It's nice to meet you."
+    mock_message_stop_event.message.content[0].type = "text"
+    mock_message_stop_event.message.model = "claude-3-opus-20240229"
+    mock_message_stop_event.message.role = "assistant"
+    mock_message_stop_event.message.stop_reason = "end_turn"
+    mock_message_stop_event.message.stop_sequence = None
+    mock_message_stop_event.message.type = "message"
+    mock_message_stop_event.message.usage = MagicMock(spec=Usage)
+    mock_message_stop_event.message.usage.input_tokens = 41
+    mock_message_stop_event.message.usage.output_tokens = 84
+
+    # Combine all mock events into a list
+    stream_events = [
+        mock_raw_message_start_event,
+        mock_raw_content_block_start_event,
+        mock_raw_content_block_delta_event,
+        mock_text_event,
+        mock_content_block_stop_event,
+        mock_raw_message_delta_event,
+        mock_message_stop_event,
     ]
-    chat_completion_response.content = content
 
-    chat_completion_response_empty = MagicMock()
-    chat_completion_response_empty.content = []
+    async def async_generator():
+        for event in stream_events:
+            yield event
+
+    # Create an AsyncMock for the stream
+    stream_mock = AsyncMock()
+    stream_mock.__aenter__.return_value = async_generator()
 
-    # Create a MagicMock for the messages attribute
     messages_mock = MagicMock()
-    messages_mock.stream = chat_completion_response
-
-    generator_mock = MagicMock()
-    generator_mock.__aiter__.return_value = [chat_completion_response_empty, chat_completion_response]
-
+    messages_mock.stream.return_value = stream_mock
+
     client.messages = messages_mock
-    
+
     return client
 
 
@@ -72,7 +165,10 @@ async def test_complete_chat_contents(
     mock_settings: AnthropicChatPromptExecutionSettings,
     mock_anthropic_client_completion: AsyncAnthropic,
 ):
-    chat_history = MagicMock()
+    chat_history = ChatHistory()
+    chat_history.add_user_message("test_user_message")
+    chat_history.add_assistant_message("test_assistant_message")
+
     arguments = KernelArguments()
     chat_completion_base = AnthropicChatCompletion(
         ai_model_id="test_model_id", service_id="test", api_key="", async_client=mock_anthropic_client_completion
@@ -81,6 +177,7 @@ async def test_complete_chat_contents(
     content: list[ChatMessageContent] = await chat_completion_base.get_chat_message_contents(
         chat_history=chat_history, settings=mock_settings, kernel=kernel, arguments=arguments
     )
+
     assert content is not None