Harrison/blockchain docloader (#3491)

Co-authored-by: Jon Saginaw <saginawj@users.noreply.github.com>

tests/integration_tests/document_loaders/test_blockchain.py

@@ -0,0 +1,64 @@
+import os
+
+import pytest
+
+from langchain.document_loaders import BlockchainDocumentLoader
+from langchain.document_loaders.blockchain import BlockchainType
+
+if "ALCHEMY_API_KEY" in os.environ:
+    alchemyKeySet = True
+    apiKey = os.environ["ALCHEMY_API_KEY"]
+else:
+    alchemyKeySet = False
+
+
+@pytest.mark.skipif(not alchemyKeySet, reason="Alchemy API key not provided.")
+def test_get_nfts_valid_contract() -> None:
+    contract_address = (
+        "0x1a92f7381b9f03921564a437210bb9396471050c"  # CoolCats contract address
+    )
+    result = BlockchainDocumentLoader(contract_address).load()
+    assert len(result) > 0, "No NFTs returned"
+
+
+@pytest.mark.skipif(not alchemyKeySet, reason="Alchemy API key not provided.")
+def test_get_nfts_with_pagination() -> None:
+    contract_address = (
+        "0x1a92f7381b9f03921564a437210bb9396471050c"  # CoolCats contract address
+    )
+    startToken = 20
+
+    result = BlockchainDocumentLoader(
+        contract_address,
+        BlockchainType.ETH_MAINNET,
+        api_key=apiKey,
+        startToken=startToken,
+    ).load()
+
+    assert len(result) > 0, "No NFTs returned"
+
+
+@pytest.mark.skipif(not alchemyKeySet, reason="Alchemy API key not provided.")
+def test_get_nfts_polygon() -> None:
+    contract_address = (
+        "0x448676ffCd0aDf2D85C1f0565e8dde6924A9A7D9"  # Polygon contract address
+    )
+    result = BlockchainDocumentLoader(
+        contract_address, BlockchainType.POLYGON_MAINNET
+    ).load()
+    assert len(result) > 0, "No NFTs returned"
+
+
+@pytest.mark.skipif(not alchemyKeySet, reason="Alchemy API key not provided.")
+def test_get_nfts_invalid_contract() -> None:
+    contract_address = (
+        "0x111D4e82EA7eCA7F62c3fdf6D39A541be95Bf111"  # Invalid contract address
+    )
+
+    with pytest.raises(ValueError) as error_NoNfts:
+        BlockchainDocumentLoader(contract_address).load()
+
+    assert (
+        str(error_NoNfts.value)
+        == "No NFTs found for contract address " + contract_address
+    )