Convert regex '\Z' to '$'

See https://github.com/swagger-api/swagger-editor/issues/1601.

src/drf_yasg/inspectors/field.py

@@ -211,7 +211,14 @@ def find_regex(regex_field):
             regex_validator = validator
 
     # regex_validator.regex should be a compiled re object...
-    return getattr(getattr(regex_validator, 'regex', None), 'pattern', None)
+    pattern = getattr(getattr(regex_validator, 'regex', None), 'pattern', None)
+    if pattern:
+        # attempt some basic cleanup to remove regex constructs not supported by JavaScript
+        #  -- swagger uses javascript-style regexes - see https://github.com/swagger-api/swagger-editor/issues/1601
+        if pattern.endswith('\\Z') or pattern.endswith('\\z'):
+            pattern = pattern[:-2] + '$'
+
+    return pattern
 
 
 numeric_fields = (serializers.IntegerField, serializers.FloatField, serializers.DecimalField)

src/drf_yasg/inspectors/view.py

@@ -162,9 +162,7 @@ class SwaggerAutoSchema(ViewInspector):
 
         default_status = guess_response_status(method)
         default_schema = ''
-        if method == 'post':
-            default_schema = self.get_request_serializer() or self.get_view_serializer()
-        elif method in ('get', 'put', 'patch'):
+        if method in ('get', 'post', 'put', 'patch'):
             default_schema = self.get_request_serializer() or self.get_view_serializer()
 
         default_schema = default_schema or ''