Validate user messages on chat completions endpoint

Signed-off-by: Mateus Devino <mdevino@ibm.com>

Author: mdevino

src/clients/openai.rs

@@ -219,7 +219,17 @@ impl TryFrom<Map<String, Value>> for ChatCompletionsRequest {
         }
         let messages = if let Some(messages) = value.get("messages") {
             Vec::<Message>::deserialize(messages)
-                .map_err(|_| ValidationError::Invalid("error deserializing `messages`".into()))
+                .map(|messages| {
+                    for message in &messages {
+                        if message.role == Role::User && message.content.is_none() {
+                            return Err(ValidationError::Invalid(
+                                "`content` is mandatory for user messages".into(),
+                            ));
+                        }
+                    }
+                    Ok(messages)
+                })
+                .map_err(|_| ValidationError::Invalid("error deserializing `messages`".into()))?
         } else {
             Err(ValidationError::Required("messages".into()))
         }?;

tests/chat_completions_detection.rs

@@ -1037,5 +1037,35 @@ async fn orchestrator_validation_error() -> Result<(), anyhow::Error> {
         "failed on non-existing input detector scenario"
     );
 
+    // Non-existing output detector scenario
+    let response = orchestrator_server
+        .post(ORCHESTRATOR_CHAT_COMPLETIONS_DETECTION_ENDPOINT)
+        .json(&json!({
+            "model": MODEL_ID,
+            "detectors": {
+                "input": {},
+                "output": {
+                    NON_EXISTING_DETECTOR: {},
+                }
+            },
+            "messages": [{
+                "role": "user",
+                "name": "string"
+            }],
+        }))
+        .send()
+        .await?;
+
+    let results = response.json::<OrchestratorError>().await?;
+    debug!("{results:#?}");
+    assert_eq!(
+        results,
+        OrchestratorError {
+            code: 422,
+            details: "`content` is mandatory for user messages".into()
+        },
+        "failed on user message missing `content` scenario"
+    );
+
     Ok(())
 }