Register a validation error response

Add new config: VALIDATION_ERROR_CODE (defaults to 422) VALIDATION_ERROR_DESCRIPTION (defaults to 'Validation error')
apiflask · Feb 20, 2021 · c3d7c3b · c3d7c3b
1 parent f992d99
commit c3d7c3b
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Showing 4 changed files with 86 additions and 3 deletions.
diff --git a/apiflask/core.py b/apiflask/core.py
@@ -20,6 +20,7 @@
     HTTPTokenAuth = None
 
 from .exceptions import ValidationError
+from .schemas import validation_error_response_schema
 
 
 class APIFlask(Flask):
@@ -34,6 +35,8 @@ class APIFlask(Flask):
             'OPENAPI_TAGS': None,
             '200_RESPONSE_DESCRIPTION': 'Successful response',
             '204_RESPONSE_DESCRIPTION': 'Empty response',
+            'VALIDATION_ERROR_CODE': 400,
+            'VALIDATION_ERROR_DESCRIPTION': 'Validation error'
         }
     )
 
@@ -356,6 +359,19 @@ def resolver(schema):
                         security[view_func._spec['auth']]: view_func._spec[
                             'roles']
                     }]
+
+                if view_func._spec.get('body') or view_func._spec.get('args'):
+                    code = self.config['VALIDATION_ERROR_CODE']
+                    operation['responses'][code] = {
+                        'content': {
+                            'application/json': {
+                                'schema': validation_error_response_schema
+                            }
+                        }
+                    }
+                    operation['responses'][code]['description'] = \
+                        self.config['VALIDATION_ERROR_DESCRIPTION']
+
                 operations[method.lower()] = operation
 
             path_arguments = re.findall(r'<(([^:]+:)?([^>]+))>', rule.rule)

diff --git a/apiflask/decorators.py b/apiflask/decorators.py
@@ -1,18 +1,17 @@
 from functools import wraps
 
-from flask import Response, jsonify
+from flask import Response, jsonify, current_app
 from webargs.flaskparser import FlaskParser as BaseFlaskParser
 
 from apiflask.exceptions import ValidationError
 
 
 class FlaskParser(BaseFlaskParser):
-    DEFAULT_VALIDATION_STATUS = 400
 
     def handle_error(self, error, req, schema, *, error_status_code,
                      error_headers):
         raise ValidationError(
-            error_status_code or self.DEFAULT_VALIDATION_STATUS,
+            error_status_code or current_app.config['VALIDATION_ERROR_CODE'],
             error.messages)
 
 

diff --git a/apiflask/schemas.py b/apiflask/schemas.py
@@ -1,5 +1,28 @@
 from flask_marshmallow.schema import Schema    # noqa: F401
 
 
+validation_error_response_schema = {
+    "type": "object",
+    "properties": {
+        "messages": {
+            "type": "object",
+            "properties": {
+                "<location>": {
+                    "type": "object",
+                    "properties": {
+                        "<field_name>": {
+                            "type": "array",
+                            "items": {
+                                "type": "string"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 class PaginationSchema(Schema):
     pass
diff --git a/tests/test_apiflask.py b/tests/test_apiflask.py
@@ -532,3 +532,48 @@ def no_schema():
             '204']['description'] == 'Nothing'
         assert rv.json['paths']['/bar']['get']['responses'][
             '200']['description'] == 'It works'
+
+    def test_register_validation_error_response(self):
+        app = self.create_app()
+        error_code = str(app.config['VALIDATION_ERROR_CODE'])
+
+        @app.post('/foo')
+        @body(Schema)
+        def foo():
+            pass
+
+        @app.get('/bar')
+        @arguments(Schema)
+        def bar():
+            pass
+
+        client = app.test_client()
+        rv = client.get('/openapi.json')
+        assert rv.status_code == 200
+        validate_spec(rv.json)
+        assert rv.json['paths']['/foo']['post']['responses'][
+            error_code] is not None
+        assert rv.json['paths']['/foo']['post']['responses'][
+            error_code]['description'] == 'Validation error'
+        assert rv.json['paths']['/bar']['get']['responses'][
+            error_code] is not None
+        assert rv.json['paths']['/bar']['get']['responses'][
+            error_code]['description'] == 'Validation error'
+
+    def test_validation_error_config(self):
+        app = self.create_app()
+        app.config['VALIDATION_ERROR_CODE'] = 422
+        app.config['VALIDATION_ERROR_DESCRIPTION'] = 'Bad'
+
+        @app.post('/foo')
+        @body(Schema)
+        def foo():
+            pass
+
+        client = app.test_client()
+        rv = client.get('/openapi.json')
+        assert rv.status_code == 200
+        validate_spec(rv.json)
+        assert rv.json['paths']['/foo']['post']['responses']['422'] is not None
+        assert rv.json['paths']['/foo']['post']['responses'][
+            '422']['description'] == 'Bad'