chunker and ui

tests/chunker/test_collector.py

@@ -0,0 +1,103 @@
+"""
+Tests for ResultCollector — ordered reassembly, out-of-order buffering, duplicates.
+
+Demonstrates: TDD (Interview Topic 8) — testing algorithms (heapq reassembly).
+"""
+
+import pytest
+
+from core.chunker.collector import ResultCollector
+from core.chunker.exceptions import ReassemblyError
+
+
+class TestResultCollector:
+    def test_in_order_emission(self, make_result):
+        """Results arriving in order are emitted immediately."""
+        collector = ResultCollector(total_chunks=3)
+
+        emitted = collector.add(make_result(0))
+        assert len(emitted) == 1
+        assert emitted[0].sequence == 0
+
+        emitted = collector.add(make_result(1))
+        assert len(emitted) == 1
+
+        emitted = collector.add(make_result(2))
+        assert len(emitted) == 1
+
+        assert collector.is_complete
+
+    def test_out_of_order_buffering(self, make_result):
+        """Out-of-order results are buffered until gaps fill."""
+        collector = ResultCollector(total_chunks=3)
+
+        # Arrive: 2, 0, 1
+        emitted = collector.add(make_result(2))
+        assert len(emitted) == 0
+        assert collector.buffered_count == 1
+
+        emitted = collector.add(make_result(0))
+        assert len(emitted) == 1  # Only 0 emitted, 1 still missing
+
+        emitted = collector.add(make_result(1))
+        assert len(emitted) == 2  # 1 and 2 now emittable
+        assert collector.is_complete
+
+    def test_reverse_order(self, make_result):
+        """All results arrive in reverse — only last add emits everything."""
+        collector = ResultCollector(total_chunks=4)
+
+        for seq in [3, 2, 1]:
+            emitted = collector.add(make_result(seq))
+            assert len(emitted) == 0
+
+        emitted = collector.add(make_result(0))
+        assert len(emitted) == 4
+        assert collector.is_complete
+
+    def test_duplicate_raises(self, make_result):
+        """Duplicate sequence number raises ReassemblyError."""
+        collector = ResultCollector(total_chunks=3)
+        collector.add(make_result(0))
+
+        with pytest.raises(ReassemblyError, match="Duplicate"):
+            collector.add(make_result(0))
+
+    def test_emitted_count(self, make_result):
+        """emitted_count tracks correctly."""
+        collector = ResultCollector(total_chunks=3)
+        assert collector.emitted_count == 0
+
+        collector.add(make_result(0))
+        assert collector.emitted_count == 1
+
+        collector.add(make_result(2))  # buffered
+        assert collector.emitted_count == 1
+
+        collector.add(make_result(1))  # releases 1 and 2
+        assert collector.emitted_count == 3
+
+    def test_get_ordered_results(self, make_result):
+        """get_ordered_results returns all emitted results in order."""
+        collector = ResultCollector(total_chunks=3)
+        collector.add(make_result(2))
+        collector.add(make_result(0))
+        collector.add(make_result(1))
+
+        ordered = collector.get_ordered_results()
+        assert [r.sequence for r in ordered] == [0, 1, 2]
+
+    def test_avg_processing_time(self, make_result):
+        """Average processing time from sliding window."""
+        collector = ResultCollector(total_chunks=2)
+        collector.add(make_result(0, processing_time=0.1))
+        collector.add(make_result(1, processing_time=0.3))
+
+        assert abs(collector.avg_processing_time - 0.2) < 0.001
+
+    def test_not_complete_when_partial(self, make_result):
+        """is_complete is False until all chunks emitted."""
+        collector = ResultCollector(total_chunks=3)
+        collector.add(make_result(0))
+        collector.add(make_result(1))
+        assert not collector.is_complete