deep_research/Cargo.toml

@@ -17,3 +17,6 @@ serde = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
+
+[dev-dependencies]
+serde_json = "1"

deep_research/src/core.rs

@@ -121,11 +121,10 @@ fn partial_findings_from_history(chat_history: &[Message]) -> String {
         })
         .collect();
 
-    if sections.is_empty() {
-        "The researcher exhausted its turn budget before gathering any usable evidence."
-            .to_string()
-    } else {
-        sections.join("\n\n")
+    match sections.is_empty() {
+        true => "The researcher exhausted its turn budget before gathering any usable evidence."
+                .to_string(),
+        false => sections.join("\n"),
     }
 }
 
@@ -313,3 +312,98 @@ async fn write_report(
         None => report,
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn truncate_leaves_short_text_untouched() {
+        assert_eq!(truncate("hello", 10), "hello");
+    }
+
+    #[test]
+    fn truncate_leaves_exact_length_text_untouched() {
+        assert_eq!(truncate("hello", 5), "hello");
+    }
+
+    #[test]
+    fn truncate_cuts_long_text_and_marks_it() {
+        assert_eq!(truncate("hello world", 5), "hello [...truncated]");
+    }
+
+    #[test]
+    fn assistant_text_extracts_text_blocks() {
+        let message = Message::assistant("found it");
+        assert_eq!(assistant_text(&message), vec!["found it".to_string()]);
+    }
+
+    #[test]
+    fn assistant_text_ignores_tool_calls() {
+        let message = Message::Assistant {
+            id: None,
+            content: rig::OneOrMany::one(AssistantContent::tool_call(
+                "call-1",
+                "search_web",
+                serde_json::json!({ "query": "test" }),
+            )),
+        };
+        assert!(assistant_text(&message).is_empty());
+    }
+
+    #[test]
+    fn assistant_text_ignores_non_assistant_messages() {
+        assert!(assistant_text(&Message::user("hi")).is_empty());
+        assert!(assistant_text(&Message::system("be careful")).is_empty());
+    }
+
+    #[test]
+    fn tool_result_text_extracts_and_truncates() {
+        let short = Message::tool_result("call-1", "short result");
+        assert_eq!(tool_result_text(&short, 100), vec!["short result".to_string()]);
+
+        let long = Message::tool_result("call-2", "0123456789");
+        assert_eq!(tool_result_text(&long, 5), vec!["01234 [...truncated]".to_string()]);
+    }
+
+    #[test]
+    fn tool_result_text_ignores_non_tool_result_content() {
+        assert!(tool_result_text(&Message::user("plain text, no tool result"), 100).is_empty());
+        assert!(tool_result_text(&Message::assistant("also ignored"), 100).is_empty());
+    }
+
+    #[test]
+    fn partial_findings_from_history_falls_back_when_nothing_usable() {
+        let history = vec![
+            Message::system("preamble"),
+            Message::Assistant {
+                id: None,
+                content: rig::OneOrMany::one(AssistantContent::tool_call(
+                    "call-1",
+                    "search_web",
+                    serde_json::json!({ "query": "test" }),
+                )),
+            },
+        ];
+
+        assert_eq!(
+            partial_findings_from_history(&history),
+            "The researcher exhausted its turn budget before gathering any usable evidence."
+        );
+    }
+
+    #[test]
+    fn partial_findings_from_history_collects_assistant_text_and_tool_results_in_order() {
+        let history = vec![
+            Message::assistant("Checking sources..."),
+            Message::tool_result("call-1", "Result A [1]"),
+            Message::assistant("Cross-checking..."),
+            Message::tool_result("call-2", "Result B [2]"),
+        ];
+
+        assert_eq!(
+            partial_findings_from_history(&history),
+            "Checking sources...\nResult A [1]\nCross-checking...\nResult B [2]"
+        );
+    }
+}