Merge branch 'fix-sqlite-serialization' into 'master'

Handle Decimal values when saving rows to SQLite databases

Closes #1344

See merge request teklia/arkindex/backend!1798

.gitlab-ci.yml

@@ -51,7 +51,7 @@ backend-tests:
   stage: test
 
   services:
-    - name: postgis/postgis:12-3.1
+    - name: postgis/postgis:14-3.2
       alias: postgres
 
   artifacts:

arkindex/documents/export/__init__.py

@@ -5,6 +5,7 @@ import sqlite3
 import tempfile
 import uuid
 from datetime import datetime, timezone
+from decimal import Decimal
 from pathlib import Path
 
 from django.conf import settings
@@ -70,6 +71,15 @@ def save_sqlite(rows, table, cursor):
         if isinstance(value, (list, dict)):
             return json.dumps(value)
 
+        # Serialize Decimal numbers as regular floats
+        # We don't care about any loss of precision because SQLite will loose that precision anyway
+        if isinstance(value, Decimal):
+            return float(value)
+
+        # Show very explicit error messages if we stumble upon an unexpected type
+        # https://docs.python.org/3.8/library/sqlite3.html#sqlite-and-python-types
+        assert value is None or isinstance(value, (int, float, str, bytes)), f'Type {type(value)} is not supported by sqlite3'
+
         return value
 
     rows = [