fix: add handling for decimal values and lists, in make_json_safe()

src/wuttaweb/util.py

@@ -24,6 +24,7 @@
 Web Utilities
 """
 
+import decimal
 import importlib
 import json
 import logging
@@ -525,17 +526,28 @@ def make_json_safe(value, key=None, warn=True):
     if value is colander.null:
         return None
 
-    # recursively convert dict
-    if isinstance(value, dict):
+    elif isinstance(value, dict):
+        # recursively convert dict
         parent = dict(value)
         for key, value in parent.items():
             parent[key] = make_json_safe(value, key=key, warn=warn)
         value = parent
 
-    # convert UUID to str
-    if isinstance(value, _uuid.UUID):
+    elif isinstance(value, list):
+        # recursively convert list
+        parent = list(value)
+        for i, value in enumerate(parent):
+            parent[i] = make_json_safe(value, key=key, warn=warn)
+        value = parent
+
+    elif isinstance(value, _uuid.UUID):
+        # convert UUID to str
         value = value.hex
 
+    elif isinstance(value, decimal.Decimal):
+        # convert decimal to float
+        value = float(value)
+
     # ensure JSON-compatibility, warn if problems
     try:
         json.dumps(value)

tests/test_util.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8; -*-
 
+import decimal
 import json
 import uuid as _uuid
 from unittest import TestCase
@@ -570,6 +571,12 @@ class TestMakeJsonSafe(TestCase):
         value = mod.make_json_safe(uuid)
         self.assertEqual(value, uuid.hex)
 
+    def test_decimal(self):
+        value = decimal.Decimal('42.42')
+        self.assertNotEqual(value, 42.42)
+        result = mod.make_json_safe(value)
+        self.assertEqual(result, 42.42)
+
     def test_dict(self):
         model = self.app.model
         person = model.Person(full_name="Betty Boop")
@@ -585,3 +592,21 @@ class TestMakeJsonSafe(TestCase):
             'foo': 'bar',
             'person': "Betty Boop",
         })
+
+    def test_list(self):
+        model = self.app.model
+        person = model.Person(full_name="Betty Boop")
+
+        data = [
+            'foo',
+            'bar',
+            person,
+        ]
+
+        self.assertRaises(TypeError, json.dumps, data)
+        value = mod.make_json_safe(data)
+        self.assertEqual(value, [
+            'foo',
+            'bar',
+            "Betty Boop",
+        ])