test: add edge case tests

tests/comparator/test_aligner_edge.py

@@ -0,0 +1,18 @@
+import sys, os
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..")))
+from comparator.aligner import align_records
+
+
+def test_align_large_key_set():
+    cobol = [{"ID": f"K{i:04d}", "V": i} for i in range(100)]
+    spark = [{"ID": f"K{i:04d}", "V": i} for i in range(100)]
+    result = align_records(cobol, spark, key_field="ID")
+    assert len(result) == 100
+    assert all(st == "MATCHED" for _, _, st in result)
+
+
+def test_align_empty_key_value():
+    cobol = [{"ID": "", "V": 1}]
+    spark = [{"ID": "", "V": 1}]
+    result = align_records(cobol, spark, key_field="ID")
+    assert len(result) == 1

tests/comparator/test_compare_edge.py

@@ -0,0 +1,15 @@
+import sys, os
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..")))
+from comparator.field_compare import compare_field, DEFAULT_TOLERANCE
+
+
+def test_negative_numbers():
+    assert compare_field("AMT", "-1500", "-1500", "decimal").status == "PASS"
+
+
+def test_mixed_precision():
+    assert compare_field("AMT", "1500.00", "1500", "decimal", DEFAULT_TOLERANCE).status == "PASS"
+
+
+def test_very_large_number():
+    assert compare_field("AMT", "9999999999", "9999999999", "decimal").status == "PASS"