[claude] Qwen3 two-model routing via task complexity classifier (#1065) v2 (#1233)

Co-authored-by: Claude (Opus 4.6) <claude@hermes.local>
Co-committed-by: Claude (Opus 4.6) <claude@hermes.local>

tests/infrastructure/test_router_classifier.py

@@ -0,0 +1,134 @@
+"""Tests for Qwen3 dual-model task complexity classifier."""
+
+import pytest
+
+from infrastructure.router.classifier import TaskComplexity, classify_task
+
+
+class TestClassifyTask:
+    """Tests for classify_task heuristics."""
+
+    # ── Simple / routine tasks ──────────────────────────────────────────────
+
+    def test_empty_messages_is_simple(self):
+        assert classify_task([]) == TaskComplexity.SIMPLE
+
+    def test_no_user_content_is_simple(self):
+        messages = [{"role": "system", "content": "You are Timmy."}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    def test_short_status_query_is_simple(self):
+        messages = [{"role": "user", "content": "status"}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    def test_list_command_is_simple(self):
+        messages = [{"role": "user", "content": "list all tasks"}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    def test_get_command_is_simple(self):
+        messages = [{"role": "user", "content": "get the latest log entry"}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    def test_short_message_under_threshold_is_simple(self):
+        messages = [{"role": "user", "content": "run the build"}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    def test_affirmation_is_simple(self):
+        messages = [{"role": "user", "content": "yes"}]
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+    # ── Complex / quality-sensitive tasks ──────────────────────────────────
+
+    def test_plan_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "plan the sprint"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_review_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "review this code"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_analyze_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "analyze performance"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_triage_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "triage the open issues"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_refactor_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "refactor the auth module"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_explain_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "explain how the router works"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_prioritize_keyword_is_complex(self):
+        messages = [{"role": "user", "content": "prioritize the backlog"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_long_message_is_complex(self):
+        long_msg = "do something " * 50  # > 500 chars
+        messages = [{"role": "user", "content": long_msg}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_numbered_list_is_complex(self):
+        messages = [
+            {
+                "role": "user",
+                "content": "1. Read the file  2. Analyze it  3. Write a report",
+            }
+        ]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_code_block_is_complex(self):
+        messages = [
+            {"role": "user", "content": "Here is the code:\n```python\nprint('hello')\n```"}
+        ]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_deep_conversation_is_complex(self):
+        messages = [
+            {"role": "user", "content": "hi"},
+            {"role": "assistant", "content": "hello"},
+            {"role": "user", "content": "ok"},
+            {"role": "assistant", "content": "yes"},
+            {"role": "user", "content": "ok"},
+            {"role": "assistant", "content": "yes"},
+            {"role": "user", "content": "now do the thing"},
+        ]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_analyse_british_spelling_is_complex(self):
+        messages = [{"role": "user", "content": "analyse this dataset"}]
+        assert classify_task(messages) == TaskComplexity.COMPLEX
+
+    def test_non_string_content_is_ignored(self):
+        """Non-string content should not crash the classifier."""
+        messages = [{"role": "user", "content": ["part1", "part2"]}]
+        # Should not raise; result doesn't matter — just must not blow up
+        result = classify_task(messages)
+        assert isinstance(result, TaskComplexity)
+
+    def test_system_message_not_counted_as_user(self):
+        """System message alone should not trigger complex keywords."""
+        messages = [
+            {"role": "system", "content": "analyze everything carefully"},
+            {"role": "user", "content": "yes"},
+        ]
+        # "analyze" is in system message (not user) — user says "yes" → simple
+        assert classify_task(messages) == TaskComplexity.SIMPLE
+
+
+class TestTaskComplexityEnum:
+    """Tests for TaskComplexity enum values."""
+
+    def test_simple_value(self):
+        assert TaskComplexity.SIMPLE.value == "simple"
+
+    def test_complex_value(self):
+        assert TaskComplexity.COMPLEX.value == "complex"
+
+    def test_lookup_by_value(self):
+        assert TaskComplexity("simple") == TaskComplexity.SIMPLE
+        assert TaskComplexity("complex") == TaskComplexity.COMPLEX