Add infrastructure for test-helper methods

.gitignore

@@ -58,3 +58,4 @@ venv.bak/
 !.vscode/tasks.json
 !.vscode/launch.json
 !.vscode/extensions.json
+/.idea

stripe/api_resources/abstract/__init__.py

@@ -23,6 +23,8 @@
 
 from stripe.api_resources.abstract.custom_method import custom_method
 
+from stripe.api_resources.abstract.test_helpers import test_helpers
+
 from stripe.api_resources.abstract.nested_resource_class_methods import (
     nested_resource_class_methods,
 )

stripe/api_resources/abstract/custom_method.py

@@ -14,13 +14,23 @@ def custom_method(name, http_verb, http_path=None, is_streaming=False):
         http_path = name
 
     def wrapper(cls):
+        # Custom method can be defined on the resource class or TestHelpers class
+        # In TestHelpers case, the _resource_cls attribute will contain the
+        # resource implementation
+        def get_resource_class(cls):
+            resource_cls = getattr(cls, "_resource_cls", None)
+            if resource_cls is None:
+                resource_cls = cls
+            return resource_cls
+
         def custom_method_request(cls, sid, **params):
+            resource_cls = get_resource_class(cls)
             url = "%s/%s/%s" % (
-                cls.class_url(),
+                resource_cls.class_url(),
                 quote_plus(util.utf8(sid)),
                 http_path,
             )
-            obj = cls._static_request(http_verb, url, **params)
+            obj = resource_cls._static_request(http_verb, url, **params)
 
             # For list objects, we have to attach the parameters so that they
             # can be referenced in auto-pagination and ensure consistency.
@@ -30,12 +40,15 @@ def custom_method_request(cls, sid, **params):
             return obj
 
         def custom_method_request_stream(cls, sid, **params):
+            resource_cls = get_resource_class(cls)
             url = "%s/%s/%s" % (
-                cls.class_url(),
+                resource_cls.class_url(),
                 quote_plus(util.utf8(sid)),
                 http_path,
             )
-            return cls._static_request_stream(http_verb, url, **params)
+            return resource_cls._static_request_stream(
+                http_verb, url, **params
+            )
 
         if is_streaming:
             class_method_impl = classmethod(custom_method_request_stream)

stripe/api_resources/abstract/test_helpers.py

@@ -0,0 +1,10 @@
+from __future__ import absolute_import, division, print_function
+
+
+def test_helpers(cls):
+    def test_helpers_getter(self):
+        return self.TestHelpers(self)
+
+    cls.TestHelpers._resource_cls = cls
+    cls.test_helpers = property(test_helpers_getter)
+    return cls

tests/api_resources/abstract/test_test_helpers_api_resource.py

@@ -0,0 +1,56 @@
+from __future__ import absolute_import, division, print_function
+
+import stripe
+from stripe import util
+
+
+class TestTestHelperAPIResource(object):
+    @stripe.api_resources.abstract.test_helpers
+    class MyTestHelpersResource(stripe.api_resources.abstract.APIResource):
+        OBJECT_NAME = "myresource"
+
+        @stripe.api_resources.abstract.custom_method(
+            "do_stuff", http_verb="post", http_path="do_the_thing"
+        )
+        class TestHelpers:
+            def __init__(self, resource):
+                self.resource = resource
+
+            def do_stuff(self, idempotency_key=None, **params):
+                url = self.resource.instance_url() + "/do_the_thing"
+                headers = util.populate_headers(idempotency_key)
+                self.resource.refresh_from(
+                    self.resource.request("post", url, params, headers)
+                )
+                return self.resource
+
+    def test_call_custom_method_class(self, request_mock):
+        request_mock.stub_request(
+            "post",
+            "/v1/myresources/mid/do_the_thing",
+            {"id": "mid", "thing_done": True},
+            rheaders={"request-id": "req_id"},
+        )
+
+        obj = self.MyTestHelpersResource.TestHelpers.do_stuff("mid", foo="bar")
+
+        request_mock.assert_requested(
+            "post", "/v1/myresources/mid/do_the_thing", {"foo": "bar"}
+        )
+        assert obj.thing_done is True
+
+    def test_call_custom_method_instance(self, request_mock):
+        request_mock.stub_request(
+            "post",
+            "/v1/myresources/mid/do_the_thing",
+            {"id": "mid", "thing_done": True},
+            rheaders={"request-id": "req_id"},
+        )
+
+        obj = self.MyTestHelpersResource.construct_from({"id": "mid"}, "mykey")
+        obj.test_helpers.do_stuff(foo="bar")
+
+        request_mock.assert_requested(
+            "post", "/v1/myresources/mid/do_the_thing", {"foo": "bar"}
+        )
+        assert obj.thing_done is True

tox.ini

@@ -39,7 +39,8 @@ deps =
     pytest-cov >= 2.8.1, < 2.11.0
     pytest-mock >= 2.0.0
     pytest-xdist >= 1.31.0
-commands = pytest --cov {posargs:-n auto}
+# ignore stripe directory as all tests are inside ./tests
+commands = pytest --cov {posargs:-n auto} --ignore stripe
 # compilation flags can be useful when prebuilt wheels cannot be used, e.g.
 # PyPy 2 needs to compile the `cryptography` module. On macOS this can be done
 # by passing the following flags: