feat: deterministic PZ log parser module + unit tests

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/pz-analyzer/tests/test_signatures.py

@@ -0,0 +1,59 @@
+"""Tests for pz_parser phase 8 — signature computation."""
+from __future__ import annotations
+
+import pathlib
+import sys
+import unittest
+
+sys.path.insert(0, str(pathlib.Path(__file__).resolve().parents[1]))
+
+import pz_parser  # noqa: E402
+
+
+class PatternIdStabilityTests(unittest.TestCase):
+    """pattern_id should be invariant under formatting variations."""
+
+    def test_pattern_id_collapses_numeric_runs(self) -> None:
+        a = pz_parser.compute_pattern_id(
+            "ERROR",
+            "General  f:0, t:1776297642, st:48,648,157,434> failed at offset 12345",
+        )
+        b = pz_parser.compute_pattern_id(
+            "ERROR",
+            "General  f:0, t:9999999999, st:99,99,99,99> failed at offset 99999",
+        )
+        self.assertEqual(a, b)
+
+    def test_pattern_id_collapses_quoted_strings_and_whitespace(self) -> None:
+        a = pz_parser.compute_pattern_id(
+            "ERROR",
+            'no such function "doStuff"   in module',
+        )
+        b = pz_parser.compute_pattern_id(
+            "ERROR",
+            'no such function "fooBarBaz" in module',
+        )
+        # Whitespace-collapse plus quoted-string-flatten => same pattern_id.
+        self.assertEqual(a, b)
+
+    def test_pattern_id_changes_with_level(self) -> None:
+        a = pz_parser.compute_pattern_id("ERROR", "exception thrown")
+        b = pz_parser.compute_pattern_id("WARN", "exception thrown")
+        self.assertNotEqual(a, b)
+
+
+class SignatureUniquenessTests(unittest.TestCase):
+    """signature should fan out across mods sharing a pattern_id."""
+
+    def test_signature_unique_per_mod_for_shared_pattern(self) -> None:
+        # Same first line, different mod_ids — different signatures, same pattern_id.
+        pat = pz_parser.compute_pattern_id("ERROR", "Lua((MOD:X)) crash")
+        sig_a = pz_parser.compute_signature(pat, "spongiesclothing")
+        sig_b = pz_parser.compute_signature(pat, "testmodalpha")
+        self.assertNotEqual(sig_a, sig_b)
+        # Both should share their pattern_id (consumer's pattern-fanout view).
+        self.assertEqual(pat[:7], "sha256:")
+
+
+if __name__ == "__main__":
+    unittest.main()