feat: add EmbeddingModelComponent for generating embeddings (#7204)

* feat: add EmbeddingModelComponent for generating embeddings

- Introduced a new EmbeddingModelComponent to generate embeddings using specified providers, starting with OpenAI.
- Updated the __init__.py file to include the new component in the exports.
- The component includes various input fields for configuration, such as provider selection, model name, API key, and additional parameters.

* update the tests.

---------

Co-authored-by: Edwin Jose <edwin.jose@datastax.com>

src/backend/tests/unit/components/embeddings/test_embedding_model_component.py

@@ -0,0 +1,89 @@
+from unittest.mock import MagicMock, patch
+
+import pytest
+from langflow.base.models.openai_constants import OPENAI_EMBEDDING_MODEL_NAMES
+from langflow.components.embeddings.embedding_model import EmbeddingModelComponent
+
+from tests.base import ComponentTestBaseWithClient
+
+
+@pytest.mark.usefixtures("client")
+class TestEmbeddingModelComponent(ComponentTestBaseWithClient):
+    @pytest.fixture
+    def component_class(self):
+        return EmbeddingModelComponent
+
+    @pytest.fixture
+    def default_kwargs(self):
+        return {
+            "provider": "OpenAI",
+            "model": "text-embedding-3-small",
+            "api_key": "test-api-key",
+            "chunk_size": 1000,
+            "max_retries": 3,
+            "show_progress_bar": False,
+        }
+
+    @pytest.fixture
+    def file_names_mapping(self):
+        """Return the file names mapping for version-specific files."""
+
+    async def test_update_build_config_openai(self, component_class, default_kwargs):
+        component = component_class(**default_kwargs)
+        build_config = {
+            "model": {"options": [], "value": ""},
+            "api_key": {"display_name": "API Key"},
+            "api_base": {"display_name": "API Base URL"},
+        }
+        updated_config = component.update_build_config(build_config, "OpenAI", "provider")
+        assert updated_config["model"]["options"] == OPENAI_EMBEDDING_MODEL_NAMES
+        assert updated_config["model"]["value"] == OPENAI_EMBEDDING_MODEL_NAMES[0]
+        assert updated_config["api_key"]["display_name"] == "OpenAI API Key"
+        assert updated_config["api_base"]["display_name"] == "OpenAI API Base URL"
+
+    @patch("langflow.components.embeddings.embedding_model.OpenAIEmbeddings")
+    async def test_build_embeddings_openai(self, mock_openai_embeddings, component_class, default_kwargs):
+        # Setup mock
+        mock_instance = MagicMock()
+        mock_openai_embeddings.return_value = mock_instance
+
+        # Create and configure the component
+        component = component_class(**default_kwargs)
+        component.provider = "OpenAI"
+        component.model = "text-embedding-3-small"
+        component.api_key = "test-key"
+        component.chunk_size = 1000
+        component.max_retries = 3
+        component.show_progress_bar = False
+
+        # Build the embeddings
+        embeddings = component.build_embeddings()
+
+        # Verify the OpenAIEmbeddings was called with the correct parameters
+        mock_openai_embeddings.assert_called_once_with(
+            model="text-embedding-3-small",
+            dimensions=None,
+            base_url=None,
+            api_key="test-key",
+            chunk_size=1000,
+            max_retries=3,
+            timeout=None,
+            show_progress_bar=False,
+            model_kwargs={},
+        )
+        assert embeddings == mock_instance
+
+    async def test_build_embeddings_openai_missing_api_key(self, component_class, default_kwargs):
+        component = component_class(**default_kwargs)
+        component.provider = "OpenAI"
+        component.api_key = None
+
+        with pytest.raises(ValueError, match="OpenAI API key is required when using OpenAI provider"):
+            component.build_embeddings()
+
+    async def test_build_embeddings_unknown_provider(self, component_class, default_kwargs):
+        component = component_class(**default_kwargs)
+        component.provider = "Unknown"
+
+        with pytest.raises(ValueError, match="Unknown provider: Unknown"):
+            component.build_embeddings()