replace nested middleware calls with reduce and partials

isso/__init__.py

@@ -46,6 +46,7 @@ import tempfile
 
 from os.path import dirname, join
 from argparse import ArgumentParser
+from functools import partial, reduce
 
 from itsdangerous import URLSafeTimedSerializer
 
@@ -56,6 +57,7 @@ from werkzeug.wsgi import SharedDataMiddleware
 from werkzeug.local import Local, LocalManager
 from werkzeug.serving import run_simple
 from werkzeug.contrib.fixers import ProxyFix
+from werkzeug.contrib.profiler import ProfilerMiddleware
 
 local = Local()
 local_manager = LocalManager([local])
@@ -158,23 +160,22 @@ def make_app(conf=None):
     else:
         logger.warn("unable to connect to HTTP server")
 
+    wrapper = [local_manager.make_middleware]
+
     if isso.conf.getboolean("server", "profile"):
-        from werkzeug.contrib.profiler import ProfilerMiddleware as Profiler
+        wrapper.append(partial(ProfilerMiddleware,
-        ProfilerMiddleware = lambda app: Profiler(app, sort_by=("cumtime", ), restrictions=("isso/(?!lib)", 10))
+            sort_by=("cumtime", ), restrictions=("isso/(?!lib)", 10)))
-    else:
-        ProfilerMiddleware = lambda app: app
 
-    app = ProxyFix(
+    wrapper.append(partial(SharedDataMiddleware, exports={
-            wsgi.SubURI(
-                wsgi.CORSMiddleware(
-                    SharedDataMiddleware(
-                        ProfilerMiddleware(
-                            local_manager.make_middleware(isso)), {
         '/js': join(dirname(__file__), 'js/'),
-                        '/css': join(dirname(__file__), 'css/')}),
+        '/css': join(dirname(__file__), 'css/')}))
-                    origin(isso.conf.getiter("general", "host")))))
 
-    return app
+    wrapper.append(partial(wsgi.CORSMiddleware,
+        origin=origin(isso.conf.getiter("general", "host"))))
+
+    wrapper.extend([wsgi.SubURI, ProxyFix])
+
+    return reduce(lambda x, f: f(x), wrapper, isso)
 
 
 def main():