Merge pull request #1609 from nickvalin1/main

Add regex pattern routing for flask apis

connexion/apis/flask_utils.py

@@ -44,7 +44,10 @@ def flaskify_endpoint(identifier, randomize=None):
 def convert_path_parameter(match, types):
     name = match.group(1)
     swagger_type = types.get(name)
-    converter = PATH_PARAMETER_CONVERTERS.get(swagger_type)
+    if swagger_type and swagger_type.startswith("regex"):
+        converter = swagger_type
+    else:
+        converter = PATH_PARAMETER_CONVERTERS.get(swagger_type)
     return "<{}{}{}>".format(
         converter or "", ":" if converter else "", name.replace("-", "_")
     )
@@ -63,6 +66,9 @@ def flaskify_path(swagger_path, types=None):
 
     >>> flaskify_path('/foo/{someint}', {'someint': 'int'})
     '/foo/<int:someint>'
+
+    >>> flaskify_path('/foo/{somestring}', {'somestring': 'regex("[0-9a-z]{20}")'})
+    '/foo/<regex("[0-9a-z]{20}"):somestring>'
     """
     if types is None:
         types = {}

connexion/apps/flask_app.py

@@ -39,6 +39,7 @@ def create_app(self):
         app.json = FlaskJSONProvider(app)
         app.url_map.converters["float"] = NumberConverter
         app.url_map.converters["int"] = IntegerConverter
+        app.url_map.converters["regex"] = FlaskRegexConverter
         return app
 
     def _apply_middleware(self, middlewares):
@@ -207,3 +208,9 @@ class IntegerConverter(werkzeug.routing.BaseConverter):
 
     def to_python(self, value):
         return int(value)
+
+
+class FlaskRegexConverter(werkzeug.routing.BaseConverter):
+    def __init__(self, url_map, *items):
+        super(FlaskRegexConverter, self).__init__(url_map)
+        self.regex = items[0]

connexion/operations/openapi.py

@@ -247,6 +247,10 @@ def get_path_parameter_types(self):
             ):
                 # path is special case for type 'string'
                 path_type = "path"
+            elif path_schema.get("type") == "string" and path_schema.get("pattern"):
+                # regex patterns are also a special case for 'string'
+                pattern = path_schema.get("pattern")
+                path_type = f'regex("{pattern}")'
             else:
                 path_type = path_schema.get("type")
             types[path_defn["name"]] = path_type

connexion/operations/swagger2.py

@@ -167,6 +167,10 @@ def get_path_parameter_types(self):
             if path_defn.get("type") == "string" and path_defn.get("format") == "path":
                 # path is special case for type 'string'
                 path_type = "path"
+            elif path_defn.get("type") == "string" and path_defn.get("pattern"):
+                # regex patterns are also a special case for 'string'
+                pattern = path_defn.get("pattern")
+                path_type = f'regex("{pattern}")'
             else:
                 path_type = path_defn.get("type")
             types[path_defn["name"]] = path_type

docs/routing.rst

@@ -341,6 +341,58 @@ Specify a route parameter's type as ``integer`` or ``number`` or its type as
 will create an equivalent Flask route ``/greeting/<path:name>``, allowing
 requests to include forward slashes in the ``name`` url variable.
 
+Regex Routing with Path Parameter Patterns
+------------------------------------------
+
+In addition to validating string parameters with the ``pattern`` property, Connexion can also use it to
+route otherwise identical requests paths, for example:
+
+.. code-block:: yaml
+
+  paths:
+    /greeting/{identifier}:
+      # ...
+      parameters:
+        - name: identifier
+          in: path
+          required: true
+          schema:
+            type: string
+            pattern: '[0-9a-z]{20}'
+    /greeting/{short_name}:
+      # ...
+      parameters:
+        - name: short_name
+          in: path
+          required: true
+          schema:
+            type: string
+            pattern: '\w*{1,10}'
+    /greeting/{long_name}:
+      # ...
+      parameters:
+        - name: long_name
+          in: path
+          required: true
+          schema:
+            type: string
+
+``/greeting/123abc456def789ghijk`` will route to the first endpoint.
+
+``/greeting/Trillian`` will route to the second endpoint.
+
+``/greeting/Tricia McMillan`` will route the the third endpoint because it has no pattern defined,
+and therefore acts as a catch-all for requests that don't match any defined patterns for the same path.
+
+NOTE: Regex values for the same path must be mutually exclusive. If not, and the regex overlaps,
+the routing behavior will be undefined.
+
+NOTE: Pattern routing in connexion v3 will slightly change the behavior of existing endpoints from connexion v2.
+In connexion v2, a request that provides a parameter that does not match
+the defined regex pattern will return a 400 error with a message about the pattern not matching.
+In connexion v3, the same request will return a 404 error.
+
+
 API Versioning and basePath
 ---------------------------
 

tests/api/test_parameters.py

@@ -591,3 +591,21 @@ def test_cookie_param(simple_app):
     response = app_client.get("/v1.0/test-cookie-param")
     assert response.status_code == 200
     assert response.json == {"cookie_value": "hello"}
+
+
+def test_unmatched_path_param_pattern(simple_app):
+    app_client = simple_app.app.test_client()
+    response = app_client.get("/v1.0/unmatched_pattern_route/Zaphod")
+    assert response.status_code == 404
+
+
+def test_matched_path_param_pattern(simple_app):
+    app_client = simple_app.app.test_client()
+
+    response = app_client.get("/v1.0/matched_pattern_route/Arthur")
+    assert response.status_code == 200
+    assert response.json == {"shard": 1}
+
+    response = app_client.get("/v1.0/matched_pattern_route/Zaphod")
+    assert response.status_code == 200
+    assert response.json == {"shard": 2}

tests/fakeapi/hello/__init__.py

@@ -655,3 +655,15 @@ def get_streaming_response():
 
 async def async_route():
     return {}, 200
+
+
+def unmatched_pattern_route(name):
+    return name
+
+
+def matched_pattern_route_shard_1(shard_1):
+    return {"shard": 1}
+
+
+def matched_pattern_route_shard_2(shard_2):
+    return {"shard": 2}

tests/fixtures/simple/openapi.yaml

@@ -1243,6 +1243,51 @@ paths:
       responses:
         200:
           description: 'OK'
+  /unmatched_pattern_route/{name}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.unmatched_pattern_route
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to greet.
+          required: true
+          schema:
+            type: string
+            pattern: '[A-M]\w*'
+      responses:
+        '200':
+          description: OK
+  /matched_pattern_route/{shard_1}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.matched_pattern_route_shard_1
+      parameters:
+        - name: shard_1
+          in: path
+          description: Shard assigned to the person.
+          required: true
+          schema:
+            type: string
+            pattern: '[A-M]\w*'
+      responses:
+        '200':
+          description: OK
+  /matched_pattern_route/{shard_2}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.matched_pattern_route_shard_2
+      parameters:
+        - name: shard_2
+          in: path
+          description: Shard assigned to the person.
+          required: true
+          schema:
+            type: string
+            pattern: '[N-Z]\w*'
+      responses:
+        '200':
+          description: OK
 
 
 servers:

tests/fixtures/simple/swagger.yaml

@@ -1053,6 +1053,49 @@ paths:
         200:
           description: 'OK'
 
+  /unmatched_pattern_route/{name}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.unmatched_pattern_route
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to greet.
+          required: true
+          type: string
+          pattern: '[A-M]\w*'
+      responses:
+        '200':
+          description: OK
+  /matched_pattern_route/{shard_1}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.matched_pattern_route_shard_1
+      parameters:
+        - name: shard_1
+          in: path
+          description: Shard assigned to the person.
+          required: true
+          type: string
+          pattern: '[A-M]\w*'
+      responses:
+        '200':
+          description: OK
+  /matched_pattern_route/{shard_2}:
+    get:
+      description: Getting a route with a pattern in the path that does not match
+      operationId: fakeapi.hello.matched_pattern_route_shard_2
+      parameters:
+        - name: shard_2
+          in: path
+          description: Shard assigned to the person.
+          required: true
+          type: string
+          pattern: '[N-Z]\w*'
+      responses:
+        '200':
+          description: OK
+
 definitions:
   new_stack:
     type: object

tests/test_flask_utils.py

@@ -14,6 +14,10 @@ def test_flaskify_path():
     )
     assert flask_utils.flaskify_path("foo/{a}/{b}", {"a": "path"}) == "foo/<path:a>/<b>"
     assert flask_utils.flaskify_path("foo/{a}", {"a": "path"}) == "foo/<path:a>"
+    assert (
+        flask_utils.flaskify_path("/foo/{a}", {"a": 'regex("[0-9a-z]{20}")'})
+        == '/foo/<regex("[0-9a-z]{20}"):a>'
+    )
 
 
 def test_flaskify_endpoint():