export: implement one2many fields

export.py

@@ -53,6 +53,8 @@
             if field and field["type"] == "many2one":
                 if len(value) != 0:
                     value.ensure_one()
+            elif field and field["type"] == "one2many":
+                islist = True
 
             if islist:
                 value = [export(item, mapping) for item in value]

tests/test_export.py

@@ -71,3 +71,21 @@
                 {"parent": {"source": "parent_id", "mapping": {"name": {}}}},
             ),
         )
+
+    def test_export_one2many_field(self):
+        m = {"children": {"source": "child_ids", "mapping": {"name": {}}}}
+        parent = self.env["res.partner"].create({"name": "my parent"})
+
+        self.assertEqual({"children": []}, export(parent, m))
+
+        self.env["res.partner"].create(
+            {"name": "Child1", "parent_id": parent.id}
+        )
+        self.assertEqual({"children": [{"name": "Child1"}]}, export(parent, m))
+        self.env["res.partner"].create(
+            {"name": "Child2", "parent_id": parent.id}
+        )
+        self.assertEqual(
+            {"children": [{"name": "Child1"}, {"name": "Child2"}]},
+            export(parent, m),
+        )