Add Hugging Face Hub LLM support (#762)

tests/llm/test_hugging_face_hub.py

@@ -0,0 +1,64 @@
+import importlib
+import os
+import unittest
+from unittest.mock import patch, MagicMock
+
+from embedchain.config import BaseLlmConfig
+from embedchain.llm.hugging_face_hub import HuggingFaceHubLlm
+
+
+class TestHuggingFaceHubLlm(unittest.TestCase):
+    def setUp(self):
+        os.environ["HUGGINGFACEHUB_ACCESS_TOKEN"] = "test_access_token"
+        self.config = BaseLlmConfig(model="google/flan-t5-xxl", max_tokens=50, temperature=0.7, top_p=0.8)
+
+    def test_init_raises_value_error_without_api_key(self):
+        os.environ.pop("HUGGINGFACEHUB_ACCESS_TOKEN")
+        with self.assertRaises(ValueError):
+            HuggingFaceHubLlm()
+
+    def test_get_llm_model_answer_raises_value_error_for_system_prompt(self):
+        llm = HuggingFaceHubLlm(self.config)
+        llm.config.system_prompt = "system_prompt"
+        with self.assertRaises(ValueError):
+            llm.get_llm_model_answer("prompt")
+
+    def test_top_p_value_within_range(self):
+        config = BaseLlmConfig(top_p=1.0)
+        with self.assertRaises(ValueError):
+            HuggingFaceHubLlm._get_answer("test_prompt", config)
+
+    def test_dependency_is_imported(self):
+        importlib_installed = True
+        try:
+            importlib.import_module("huggingface_hub")
+        except ImportError:
+            importlib_installed = False
+        self.assertTrue(importlib_installed)
+
+    @patch("embedchain.llm.hugging_face_hub.HuggingFaceHubLlm._get_answer")
+    def test_get_llm_model_answer(self, mock_get_answer):
+        mock_get_answer.return_value = "Test answer"
+
+        llm = HuggingFaceHubLlm(self.config)
+        answer = llm.get_llm_model_answer("Test query")
+
+        self.assertEqual(answer, "Test answer")
+        mock_get_answer.assert_called_once()
+
+    @patch("embedchain.llm.hugging_face_hub.HuggingFaceHub")
+    def test_hugging_face_mock(self, mock_hugging_face_hub):
+        mock_llm_instance = MagicMock()
+        mock_llm_instance.return_value = "Test answer"
+        mock_hugging_face_hub.return_value = mock_llm_instance
+
+        llm = HuggingFaceHubLlm(self.config)
+        answer = llm.get_llm_model_answer("Test query")
+
+        self.assertEqual(answer, "Test answer")
+        mock_hugging_face_hub.assert_called_once_with(
+            huggingfacehub_api_token="test_access_token",
+            repo_id="google/flan-t5-xxl",
+            model_kwargs={"temperature": 0.7, "max_new_tokens": 50, "top_p": 0.8},
+        )
+        mock_llm_instance.assert_called_once_with("Test query")