From 19ca86d8d69d37d0e953837fbba1c1934d31dc75 Mon Sep 17 00:00:00 2001
From: Ryan P Kilby <kilbyr@gmail.com>
Date: Wed, 22 May 2019 19:41:53 -0700
Subject: [PATCH] Fix lazy translation of ListField errors (#6708)

* Test init for fields w/ lazy translations
* Fix lazy translations for ListField
---
 rest_framework/fields.py           |  4 ++--
 tests/importable/__init__.py       | 17 ++++++++++++++++-
 tests/importable/test_installed.py | 17 ++++++++++++++---
 3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 179dd25c8..213134793 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -1610,10 +1610,10 @@ class ListField(Field):
         super().__init__(*args, **kwargs)
         self.child.bind(field_name='', parent=self)
         if self.max_length is not None:
-            message = self.error_messages['max_length'].format(max_length=self.max_length)
+            message = lazy(self.error_messages['max_length'].format, str)(max_length=self.max_length)
             self.validators.append(MaxLengthValidator(self.max_length, message=message))
         if self.min_length is not None:
-            message = self.error_messages['min_length'].format(min_length=self.min_length)
+            message = lazy(self.error_messages['min_length'].format, str)(min_length=self.min_length)
             self.validators.append(MinLengthValidator(self.min_length, message=message))
 
     def get_value(self, dictionary):
diff --git a/tests/importable/__init__.py b/tests/importable/__init__.py
index b36599027..ded08258c 100644
--- a/tests/importable/__init__.py
+++ b/tests/importable/__init__.py
@@ -1 +1,16 @@
-from rest_framework import compat  # noqa
+"""
+This test "app" exists to ensure that parts of Django REST Framework can be
+imported/invoked before Django itself has been fully initialized.
+"""
+
+from rest_framework import compat, serializers  # noqa
+
+
+# test initializing fields with lazy translations
+class ExampleSerializer(serializers.Serializer):
+    charfield = serializers.CharField(min_length=1, max_length=2)
+    integerfield = serializers.IntegerField(min_value=1, max_value=2)
+    floatfield = serializers.FloatField(min_value=1, max_value=2)
+    decimalfield = serializers.DecimalField(max_digits=10, decimal_places=1, min_value=1, max_value=2)
+    durationfield = serializers.DurationField(min_value=1, max_value=2)
+    listfield = serializers.ListField(min_length=1, max_length=2)
diff --git a/tests/importable/test_installed.py b/tests/importable/test_installed.py
index 072d3b2e4..c7e53af23 100644
--- a/tests/importable/test_installed.py
+++ b/tests/importable/test_installed.py
@@ -4,10 +4,21 @@ from tests import importable
 
 
 def test_installed():
-    # ensure that apps can freely import rest_framework.compat
+    # ensure the test app hasn't been removed from the test suite
     assert 'tests.importable' in settings.INSTALLED_APPS
 
 
-def test_imported():
-    # ensure that the __init__ hasn't been mucked with
+def test_compat():
     assert hasattr(importable, 'compat')
+
+
+def test_serializer_fields_initialization():
+    assert hasattr(importable, 'ExampleSerializer')
+
+    serializer = importable.ExampleSerializer()
+    assert 'charfield' in serializer.fields
+    assert 'integerfield' in serializer.fields
+    assert 'floatfield' in serializer.fields
+    assert 'decimalfield' in serializer.fields
+    assert 'durationfield' in serializer.fields
+    assert 'listfield' in serializer.fields