fix: add check for interleavedContent (#1973)

# What does this PR do?
Checks for RAGDocument of type InterleavedContent

I noticed when stepping through the code that the supported types for
`RAGDocument` included `InterleavedContent` as a content type. This type
is not checked against before putting the `doc.content` is regex matched
against. This would cause a runtime error. This change adds an explicit
check for type.

The only other part that I'm unclear on is how to handle the
`ImageContent` type since this would always just return `<image>` which
seems like an undesired behavior. Should the `InterleavedContent` type
be removed from `RAGDocument` and replaced with `URI | str`?

## Test Plan


[//]: # (## Documentation)

---------

Signed-off-by: Kevin <kpostlet@redhat.com>

tests/unit/providers/utils/__init__.py

@@ -0,0 +1,5 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.

tests/unit/providers/utils/memory/__init__.py

@@ -0,0 +1,5 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.

tests/unit/providers/utils/memory/test_vector_store.py

@@ -0,0 +1,145 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from llama_stack.apis.common.content_types import URL, TextContentItem
+from llama_stack.apis.tools import RAGDocument
+from llama_stack.providers.utils.memory.vector_store import content_from_doc
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_url():
+    """Test extracting content from RAGDocument with URL content."""
+    mock_url = URL(uri="https://example.com")
+    mock_doc = RAGDocument(document_id="foo", content=mock_url)
+
+    mock_response = MagicMock()
+    mock_response.text = "Sample content from URL"
+
+    with patch("httpx.AsyncClient") as mock_client:
+        mock_instance = AsyncMock()
+        mock_instance.get.return_value = mock_response
+        mock_client.return_value.__aenter__.return_value = mock_instance
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "Sample content from URL"
+        mock_instance.get.assert_called_once_with(mock_url.uri)
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_pdf_url():
+    """Test extracting content from RAGDocument with URL pointing to a PDF."""
+    mock_url = URL(uri="https://example.com/document.pdf")
+    mock_doc = RAGDocument(document_id="foo", content=mock_url, mime_type="application/pdf")
+
+    mock_response = MagicMock()
+    mock_response.content = b"PDF binary data"
+
+    with (
+        patch("httpx.AsyncClient") as mock_client,
+        patch("llama_stack.providers.utils.memory.vector_store.parse_pdf") as mock_parse_pdf,
+    ):
+        mock_instance = AsyncMock()
+        mock_instance.get.return_value = mock_response
+        mock_client.return_value.__aenter__.return_value = mock_instance
+        mock_parse_pdf.return_value = "Extracted PDF content"
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "Extracted PDF content"
+        mock_instance.get.assert_called_once_with(mock_url.uri)
+        mock_parse_pdf.assert_called_once_with(b"PDF binary data")
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_data_url():
+    """Test extracting content from RAGDocument with data URL content."""
+    data_url = "data:text/plain;base64,SGVsbG8gV29ybGQ="  # "Hello World" base64 encoded
+    mock_url = URL(uri=data_url)
+    mock_doc = RAGDocument(document_id="foo", content=mock_url)
+
+    with patch("llama_stack.providers.utils.memory.vector_store.content_from_data") as mock_content_from_data:
+        mock_content_from_data.return_value = "Hello World"
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "Hello World"
+        mock_content_from_data.assert_called_once_with(data_url)
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_string():
+    """Test extracting content from RAGDocument with string content."""
+    content_string = "This is plain text content"
+    mock_doc = RAGDocument(document_id="foo", content=content_string)
+
+    result = await content_from_doc(mock_doc)
+
+    assert result == content_string
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_string_url():
+    """Test extracting content from RAGDocument with string URL content."""
+    url_string = "https://example.com"
+    mock_doc = RAGDocument(document_id="foo", content=url_string)
+
+    mock_response = MagicMock()
+    mock_response.text = "Sample content from URL string"
+
+    with patch("httpx.AsyncClient") as mock_client:
+        mock_instance = AsyncMock()
+        mock_instance.get.return_value = mock_response
+        mock_client.return_value.__aenter__.return_value = mock_instance
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "Sample content from URL string"
+        mock_instance.get.assert_called_once_with(url_string)
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_string_pdf_url():
+    """Test extracting content from RAGDocument with string URL pointing to a PDF."""
+    url_string = "https://example.com/document.pdf"
+    mock_doc = RAGDocument(document_id="foo", content=url_string, mime_type="application/pdf")
+
+    mock_response = MagicMock()
+    mock_response.content = b"PDF binary data"
+
+    with (
+        patch("httpx.AsyncClient") as mock_client,
+        patch("llama_stack.providers.utils.memory.vector_store.parse_pdf") as mock_parse_pdf,
+    ):
+        mock_instance = AsyncMock()
+        mock_instance.get.return_value = mock_response
+        mock_client.return_value.__aenter__.return_value = mock_instance
+        mock_parse_pdf.return_value = "Extracted PDF content from string URL"
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "Extracted PDF content from string URL"
+        mock_instance.get.assert_called_once_with(url_string)
+        mock_parse_pdf.assert_called_once_with(b"PDF binary data")
+
+
+@pytest.mark.asyncio
+async def test_content_from_doc_with_interleaved_content():
+    """Test extracting content from RAGDocument with InterleavedContent (the new case added in the commit)."""
+    interleaved_content = [TextContentItem(text="First item"), TextContentItem(text="Second item")]
+    mock_doc = RAGDocument(document_id="foo", content=interleaved_content)
+
+    with patch("llama_stack.providers.utils.memory.vector_store.interleaved_content_as_str") as mock_interleaved:
+        mock_interleaved.return_value = "First item\nSecond item"
+
+        result = await content_from_doc(mock_doc)
+
+        assert result == "First item\nSecond item"
+        mock_interleaved.assert_called_once_with(interleaved_content)