chunker and ui

tests/chunker/test_processor.py

@@ -0,0 +1,98 @@
+"""
+Tests for Processor implementations — ChecksumProcessor, SimulatedDecodeProcessor, CompositeProcessor.
+
+Demonstrates: TDD (Interview Topic 8) — ABC contract, parametrized tests.
+"""
+
+import pytest
+
+from core.chunker.exceptions import ChunkChecksumError
+from core.chunker.models import Chunk
+from core.chunker.processor import (
+    ChecksumProcessor,
+    CompositeProcessor,
+    Processor,
+    SimulatedDecodeProcessor,
+)
+
+
+class TestChecksumProcessor:
+    def test_valid_time_range(self, sample_chunk):
+        """Valid time range passes."""
+        proc = ChecksumProcessor()
+        result = proc.process(sample_chunk)
+        assert result.success is True
+        assert result.checksum_valid is True
+        assert result.processing_time > 0
+
+    def test_invalid_time_range(self):
+        """Invalid time range raises ChunkChecksumError."""
+        chunk = Chunk(
+            sequence=0,
+            start_time=10.0,
+            end_time=10.0,  # zero duration
+            source_path="/fake.mp4",
+            duration=0.0,
+        )
+        proc = ChecksumProcessor()
+        with pytest.raises(ChunkChecksumError) as exc_info:
+            proc.process(chunk)
+        assert exc_info.value.sequence == 0
+
+    def test_sequence_preserved(self, make_chunk):
+        """Result carries the chunk's sequence number."""
+        chunk = make_chunk(42)
+        proc = ChecksumProcessor()
+        result = proc.process(chunk)
+        assert result.sequence == 42
+
+
+class TestSimulatedDecodeProcessor:
+    def test_processes_successfully(self, sample_chunk):
+        """Simulated decode always succeeds."""
+        proc = SimulatedDecodeProcessor(ms_per_second=1.0)
+        result = proc.process(sample_chunk)
+        assert result.success is True
+        assert result.processing_time > 0
+
+    def test_time_proportional_to_duration(self):
+        """Longer chunks take longer."""
+        short = Chunk(0, 0.0, 1.0, "/fake.mp4", 1.0)
+        long = Chunk(1, 0.0, 10.0, "/fake.mp4", 10.0)
+
+        proc = SimulatedDecodeProcessor(ms_per_second=50.0)
+        r_short = proc.process(short)
+        r_long = proc.process(long)
+
+        assert r_long.processing_time > r_short.processing_time
+
+
+class TestCompositeProcessor:
+    def test_chains_processors(self, sample_chunk):
+        """Composite runs all processors in sequence."""
+        proc = CompositeProcessor([
+            ChecksumProcessor(),
+            SimulatedDecodeProcessor(ms_per_second=1.0),
+        ])
+        result = proc.process(sample_chunk)
+        assert result.success is True
+
+    def test_stops_on_failure(self):
+        """If first processor raises, composite propagates the error."""
+        bad_chunk = Chunk(0, 10.0, 10.0, "/fake.mp4", 0.0)  # invalid range
+        proc = CompositeProcessor([
+            ChecksumProcessor(),
+            SimulatedDecodeProcessor(ms_per_second=1.0),
+        ])
+        with pytest.raises(ChunkChecksumError):
+            proc.process(bad_chunk)
+
+    def test_requires_at_least_one(self):
+        """Empty processor list raises ValueError."""
+        with pytest.raises(ValueError, match="at least one"):
+            CompositeProcessor([])
+
+    def test_is_processor(self):
+        """CompositeProcessor is a Processor."""
+        proc = CompositeProcessor([ChecksumProcessor()])
+        assert isinstance(proc, Processor)