fix: check duplicates schemas when loading swagger

openapi_spec_validator/handlers/compat.py

@@ -4,5 +4,36 @@
 except ImportError:
     from yaml import SafeLoader
 
+from jsonschema.exceptions import ValidationError
 
-__all__ = ['SafeLoader', ]
+
+class UniqueSchemasLoader(SafeLoader):
+    """Loader that checks that schemas definitions are unique"""
+
+    POSSIBLE_SCHEMAS_YAML_PATHS = ["definitions", "components.schemas"]
+
+    def construct_mapping(self, node, deep=True):
+        self._check_for_duplicate_schemas_definitions(node, deep, self.POSSIBLE_SCHEMAS_YAML_PATHS)
+        return super().construct_mapping(node, deep)
+
+    def _check_for_duplicate_schemas_definitions(self, node, deep, possible_schemas_yaml_paths):
+        for schemas_yaml_path in possible_schemas_yaml_paths:
+            keys = []
+            for key_node, value_node in node.value:
+                if schemas_yaml_path:
+                    if key_node.value == schemas_yaml_path.split(".")[0]:
+                        return self._check_for_duplicate_schemas_definitions(
+                            value_node,
+                            deep,
+                            possible_schemas_yaml_paths=[
+                                ".".join(schemas_yaml_path.split(".")[1:])
+                            ],
+                        )
+                else:
+                    key = self.construct_object(key_node, deep=deep)
+                    if key in keys:
+                        raise ValidationError(f"Duplicate definition for {key} schema.")
+                    keys.append(key)
+
+
+__all__ = ["SafeLoader", "UniqueSchemasLoader"]

openapi_spec_validator/handlers/file.py

@@ -5,14 +5,14 @@
 from yaml import load
 
 from openapi_spec_validator.handlers.base import BaseHandler
-from openapi_spec_validator.handlers.compat import SafeLoader
+from openapi_spec_validator.handlers.compat import UniqueSchemasLoader
 from openapi_spec_validator.handlers.utils import uri_to_path
 
 
 class FileObjectHandler(BaseHandler):
     """OpenAPI spec validator file-like object handler."""
 
-    def __init__(self, loader=SafeLoader):
+    def __init__(self, loader=UniqueSchemasLoader):
         self.loader = loader
 
     def __call__(self, f):

tests/integration/data/v2.0/petstore_duplicate_schemas_def.yaml

@@ -0,0 +1,113 @@
+swagger: "2.0"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+host: petstore.swagger.io
+basePath: /v1
+schemes:
+  - http
+consumes:
+  - application/json
+produces:
+  - application/json
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      tags:
+        - pets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          required: false
+          type: integer
+          format: int32
+      responses:
+        200:
+          description: A paged array of pets
+          headers:
+            x-next:
+              type: string
+              description: A link to the next page of responses
+          schema:
+            $ref: '#/definitions/Pets'
+        default:
+          description: unexpected error
+          schema:
+            $ref: '#/definitions/Error'
+    post:
+      summary: Create a pet
+      operationId: createPets
+      tags:
+        - pets
+      responses:
+        '201':
+          description: Null response
+        default:
+          description: unexpected error
+          schema:
+            $ref: '#/definitions/Error'
+  /pets/{petId}:
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      parameters:
+        - name: petId
+          in: path
+          required: true
+          description: The id of the pet to retrieve
+          type: string
+      responses:
+        '200':
+          description: Expected response to a valid request
+          schema:
+            $ref: '#/definitions/Pets'
+        default:
+          description: unexpected error
+          schema:
+            $ref: '#/definitions/Error'
+definitions:
+  Pet:
+    required:
+      - id
+      - name
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+      tag:
+        type: string
+  Pet:
+    required:
+      - id
+      - name
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+      tag:
+        type: string
+  Pets:
+    type: array
+    items:
+      $ref: '#/definitions/Pet'
+  Error:
+    required:
+      - code
+      - message
+    properties:
+      code:
+        type: integer
+        format: int32
+      message:
+        type: string

tests/integration/data/v3.0/petstore_duplicate_schemas_def.yaml

@@ -0,0 +1,115 @@
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+  - url: http://petstore.swagger.io/v1
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      tags:
+        - pets
+      parameters:
+        - name: limit
+          in: query
+          description: How many items to return at one time (max 100)
+          required: false
+          schema:
+            type: integer
+            format: int32
+      responses:
+        200:
+          description: An paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              schema:
+                type: string
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+    post:
+      summary: Create a pet
+      operationId: createPets
+      tags:
+        - pets
+      responses:
+        '201':
+          description: Null response
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+  /pets/{petId}:
+    get:
+      summary: Info for a specific pet
+      operationId: showPetById
+      tags:
+        - pets
+      parameters:
+        - name: petId
+          in: path
+          required: true
+          description: The id of the pet to retrieve
+          schema:
+            type: string
+      responses:
+        '200':
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pets"
+        default:
+          description: unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+components:
+  schemas:
+    Pet:
+      required:
+        - id
+        - name
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+        $ref:
+          type: string
+    Pets:
+      type: array
+      items:
+        $ref: "#/components/schemas/Pet"
+    Pets:
+      type: array
+      items:
+        $ref: "#/components/schemas/Pet"
+    Error:
+      required:
+        - code
+        - message
+      properties:
+        code:
+          type: integer
+          format: int32
+        message:
+          type: string