[Feature] Add support for AWS Bedrock LLM (#1189)

Co-authored-by: Deven Patel <deven298@yahoo.com>

tests/llm/test_aws_bedrock.py

@@ -0,0 +1,56 @@
+import pytest
+from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
+
+from embedchain.config import BaseLlmConfig
+from embedchain.llm.aws_bedrock import AWSBedrockLlm
+
+
+@pytest.fixture
+def config(monkeypatch):
+    monkeypatch.setenv("AWS_ACCESS_KEY_ID", "test_access_key_id")
+    monkeypatch.setenv("AWS_SECRET_ACCESS_KEY", "test_secret_access_key")
+    monkeypatch.setenv("OPENAI_API_KEY", "test_api_key")
+    config = BaseLlmConfig(
+        model="amazon.titan-text-express-v1",
+        model_kwargs={
+            "temperature": 0.5,
+            "topP": 1,
+            "maxTokenCount": 1000,
+        },
+    )
+    yield config
+    monkeypatch.delenv("AWS_ACCESS_KEY_ID")
+    monkeypatch.delenv("AWS_SECRET_ACCESS_KEY")
+    monkeypatch.delenv("OPENAI_API_KEY")
+
+
+def test_get_llm_model_answer(config, mocker):
+    mocked_get_answer = mocker.patch("embedchain.llm.aws_bedrock.AWSBedrockLlm._get_answer", return_value="Test answer")
+
+    llm = AWSBedrockLlm(config)
+    answer = llm.get_llm_model_answer("Test query")
+
+    assert answer == "Test answer"
+    mocked_get_answer.assert_called_once_with("Test query", config)
+
+
+def test_get_llm_model_answer_empty_prompt(config, mocker):
+    mocked_get_answer = mocker.patch("embedchain.llm.aws_bedrock.AWSBedrockLlm._get_answer", return_value="Test answer")
+
+    llm = AWSBedrockLlm(config)
+    answer = llm.get_llm_model_answer("")
+
+    assert answer == "Test answer"
+    mocked_get_answer.assert_called_once_with("", config)
+
+
+def test_get_llm_model_answer_with_streaming(config, mocker):
+    config.stream = True
+    mocked_bedrock_chat = mocker.patch("embedchain.llm.aws_bedrock.Bedrock")
+
+    llm = AWSBedrockLlm(config)
+    llm.get_llm_model_answer("Test query")
+
+    mocked_bedrock_chat.assert_called_once()
+    callbacks = [callback[1]["callbacks"] for callback in mocked_bedrock_chat.call_args_list]
+    assert any(isinstance(callback[0], StreamingStdOutCallbackHandler) for callback in callbacks)