feat: add basic progress page/indicator support

so far "delete results" (for Raw Settings) is the only use case.

user cancel is not yet supported

tests/test_progress.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8; -*-
+
+from unittest import TestCase
+
+from pyramid import testing
+from beaker.session import Session as BeakerSession
+
+from wuttaweb import progress as mod
+
+
+class TestGetBasicSession(TestCase):
+
+    def setUp(self):
+        self.request = testing.DummyRequest()
+
+    def test_basic(self):
+        session = mod.get_basic_session(self.request)
+        self.assertIsInstance(session, BeakerSession)
+        self.assertFalse(session.use_cookies)
+
+
+class TestGetProgressSession(TestCase):
+
+    def setUp(self):
+        self.request = testing.DummyRequest()
+
+    def test_basic(self):
+        self.request.session.id = 'mockid'
+        session = mod.get_progress_session(self.request, 'foo')
+        self.assertIsInstance(session, BeakerSession)
+        self.assertEqual(session.id, 'mockid.progress.foo')
+
+
+class TestSessionProgress(TestCase):
+
+    def setUp(self):
+        self.request = testing.DummyRequest()
+        self.request.session.id = 'mockid'
+
+    def test_error_url(self):
+        factory = mod.SessionProgress(self.request, 'foo', success_url='/blart')
+        self.assertEqual(factory.error_url, '/blart')
+
+    def test_basic(self):
+
+        # sanity / coverage check
+        factory = mod.SessionProgress(self.request, 'foo')
+        prog = factory("doing things", 2)
+        prog.update(1)
+        prog.update(2)
+        prog.handle_success()
+
+    def test_error(self):
+
+        # sanity / coverage check
+        factory = mod.SessionProgress(self.request, 'foo')
+        prog = factory("doing things", 2)
+        prog.update(1)
+        try:
+            raise RuntimeError('omg')
+        except Exception as error:
+            prog.handle_error(error)