From defa2974c6d3abc19be28d6b319649b8028dc966 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Tue, 25 Oct 2022 14:23:24 -0700
Subject: [PATCH] jsonify_if_needed output of convert() functions, closes #495

---
 sqlite_utils/db.py    |  2 +-
 tests/test_convert.py | 26 ++++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/sqlite_utils/db.py b/sqlite_utils/db.py
index b8e8d4b..a06f4b7 100644
--- a/sqlite_utils/db.py
+++ b/sqlite_utils/db.py
@@ -2662,7 +2662,7 @@ class Table(Queryable):
                 bar.update(1)
                 if not v:
                     return v
-                return fn(v)
+                return jsonify_if_needed(fn(v))
 
             self.db.register_function(convert_value)
             sql = "update [{table}] set {sets}{where};".format(
diff --git a/tests/test_convert.py b/tests/test_convert.py
index 796a08f..31a9d28 100644
--- a/tests/test_convert.py
+++ b/tests/test_convert.py
@@ -15,6 +15,14 @@ import pytest
             lambda value: value.upper(),
             {"title": "MIXED CASE", "abstract": "ABSTRACT"},
         ),
+        (
+            "title",
+            lambda value: {"upper": value.upper(), "lower": value.lower()},
+            {
+                "title": '{"upper": "MIXED CASE", "lower": "mixed case"}',
+                "abstract": "Abstract",
+            },
+        ),
     ),
 )
 def test_convert(fresh_db, columns, fn, expected):
@@ -81,10 +89,24 @@ def test_convert_multi(fresh_db):
     table = fresh_db["table"]
     table.insert({"title": "Mixed Case"})
     table.convert(
-        "title", lambda v: {"upper": v.upper(), "lower": v.lower()}, multi=True
+        "title",
+        lambda v: {
+            "upper": v.upper(),
+            "lower": v.lower(),
+            "both": {
+                "upper": v.upper(),
+                "lower": v.lower(),
+            },
+        },
+        multi=True,
     )
     assert list(table.rows) == [
-        {"title": "Mixed Case", "upper": "MIXED CASE", "lower": "mixed case"}
+        {
+            "title": "Mixed Case",
+            "upper": "MIXED CASE",
+            "lower": "mixed case",
+            "both": '{"upper": "MIXED CASE", "lower": "mixed case"}',
+        }
     ]