Correct INIT extraction and profile item fields

tools/test_init_table_profile.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+"""Tests for INIT field profiling. Run: py -3.11 -X utf8 tools/test_init_table_profile.py"""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+import init_table_profile as profile
+
+
+def main() -> int:
+    fixture = {
+        "records": [
+            {"id": 1, "name": "one", "fields": {"0x10": 2, "0x20": 0}},
+            {"id": 3, "name": "three", "fields": {"0x10": 2}},
+            {"id": 7, "name": "seven", "fields": {"0x10": 5}},
+        ]
+    }
+    rows = {row["base"]: row for row in profile.profile_columns(fixture)}
+    assert rows["0x10"]["population"] == 3
+    assert rows["0x10"]["coverage"] == 1.0
+    assert rows["0x10"]["distinct_values"] == 2
+    assert rows["0x10"]["min"] == 2 and rows["0x10"]["max"] == 5
+    assert rows["0x10"]["common"][0] == {"value": "2", "count": 2}
+    assert rows["0x20"]["population"] == 1
+    assert rows["0x20"]["examples"][0]["name"] == "one"
+    print("all init_table_profile checks passed")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())