Request.fake(... url_vars), plus .fake() is now documented

Also made 'from datasette import Request' shortcut work.

Closes #1697

datasette/__init__.py

@@ -1,5 +1,5 @@
 from datasette.version import __version_info__, __version__  # noqa
-from datasette.utils.asgi import Forbidden, NotFound, Response  # noqa
+from datasette.utils.asgi import Forbidden, NotFound, Request, Response  # noqa
 from datasette.utils import actor_matches_allow  # noqa
 from .hookspecs import hookimpl  # noqa
 from .hookspecs import hookspec  # noqa

datasette/utils/asgi.py

@@ -118,7 +118,7 @@ class Request:
         return dict(parse_qsl(body.decode("utf-8"), keep_blank_values=True))
 
     @classmethod
-    def fake(cls, path_with_query_string, method="GET", scheme="http"):
+    def fake(cls, path_with_query_string, method="GET", scheme="http", url_vars=None):
         """Useful for constructing Request objects for tests"""
         path, _, query_string = path_with_query_string.partition("?")
         scope = {
@@ -130,6 +130,8 @@ class Request:
             "scheme": scheme,
             "type": "http",
         }
+        if url_vars:
+            scope["url_route"] = {"kwargs": url_vars}
         return cls(scope, None)
 
 

docs/internals.rst

@@ -60,6 +60,33 @@ The object also has two awaitable methods:
 ``await request.post_body()`` - bytes
     Returns the un-parsed body of a request submitted by ``POST`` - useful for things like incoming JSON data.
 
+And a class method that can be used to create fake request objects for use in tests:
+
+``fake(path_with_query_string, method="GET", scheme="http", url_vars=None)``
+    Returns a ``Request`` instance for the specified path and method. For example:
+
+    .. code-block:: python
+
+        from datasette import Request
+        from pprint import pprint
+
+        request = Request.fake("/fixtures/facetable/", url_vars={
+            "database": "fixtures",
+            "table": "facetable"
+        })
+        pprint(request.scope)
+
+    This outputs::
+
+        {'http_version': '1.1',
+         'method': 'GET',
+         'path': '/fixtures/facetable/',
+         'query_string': b'',
+         'raw_path': b'/fixtures/facetable/',
+         'scheme': 'http',
+         'type': 'http',
+         'url_route': {'kwargs': {'database': 'fixtures', 'table': 'facetable'}}}
+
 .. _internals_multiparams:
 
 The MultiParams class

tests/test_internals_request.py

@@ -75,6 +75,13 @@ def test_request_args():
         request.args["missing"]
 
 
+def test_request_fake_url_vars():
+    request = Request.fake("/")
+    assert request.url_vars == {}
+    request = Request.fake("/", url_vars={"database": "fixtures"})
+    assert request.url_vars == {"database": "fixtures"}
+
+
 def test_request_repr():
     request = Request.fake("/foo?multi=1&multi=2&single=3")
     assert (