Don't rerank empty docs

CHANGELOG.md

@@ -30,6 +30,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Missing `maxTokens` inference parameter in `AmazonBedrockPromptDriver`.
 - Incorrect model in `OpenAiDriverConfig`'s `text_to_speech_driver`.
 - Crash when using `CohereRerankDriver` with `CsvRowArtifact`s.
+- Crash when passing "empty" Artifacts to `CohereRerankDriver`.
 
 
 ## [0.30.2] - 2024-08-26

griptape/drivers/rerank/cohere_rerank_driver.py

@@ -24,7 +24,9 @@ class CohereRerankDriver(BaseRerankDriver):
     )
 
     def run(self, query: str, artifacts: list[TextArtifact]) -> list[TextArtifact]:
-        artifacts_dict = {str(hash(a.to_text())): a for a in artifacts}
+        # Cohere errors out if passed "empty" documents
+        artifacts_dict = {str(hash(a.to_text())): a for a in artifacts if a}
+
         response = self.client.rerank(
             model=self.model,
             query=query,

tests/unit/drivers/rerank/test_cohere_rerank_driver.py

@@ -20,8 +20,21 @@ def mock_client(self, mocker):
 
         return mock_client
 
+    @pytest.fixture()
+    def mock_empty_client(self, mocker):
+        mock_client = mocker.patch("cohere.Client").return_value
+        mock_client.rerank.return_value.results = []
+
+        return mock_client
+
     def test_run(self, mock_client):
         driver = CohereRerankDriver(api_key="api-key")
         result = driver.run("hello", artifacts=[TextArtifact("foo"), TextArtifact("bar")])
 
         assert len(result) == 2
+
+    def test_run_empty_artifacts(self, mock_empty_client):
+        driver = CohereRerankDriver(api_key="api-key")
+        result = driver.run("hello", artifacts=[TextArtifact(""), TextArtifact("  ")])
+
+        assert len(result) == 0