Support wildcards in unaffected paths.

This commit adds ability to use wildcards denoted by the '*' character
in unaffected paths. The wildcard will match a sequence of zero
or more arbitrary characters.

Example: /*/student_view

splash/middleware.py

@@ -2,6 +2,7 @@
 Splash screen - Middleware
 """
 import logging
+import re
 
 from django.shortcuts import redirect
 
@@ -28,8 +29,10 @@ class SplashMiddleware(object):
             return
 
         # Some URLs should never be redirected
-        if request.path_info in config.unaffected_url_paths_list:
-            return
+        path_info = request.path_info
+        for unaffected_path in config.unaffected_url_paths_list:
+            if self.path_matches(path_info, unaffected_path):
+                return
 
         # Some users should never be redirected
         if request.user.username in config.unaffected_usernames_list:
@@ -39,3 +42,21 @@ class SplashMiddleware(object):
         if (cookie_value not in config.cookie_allowed_values_list and
                 request.build_absolute_uri() != config.redirect_url):
             return redirect(config.redirect_url)
+
+    def path_matches(self, path, pattern):
+        """
+        Determine whether `path` matches the `pattern`.
+
+        `pattern` may include wildcards (*) which represent a sequence of
+        zero or more arbitrary characters.
+        """
+        matches = False
+
+        if path == pattern:
+            matches = True
+        elif '*' in pattern:
+            pattern = re.escape(pattern).replace('\\*', '.*')
+            if re.match(pattern + '$', path):
+                matches = True
+
+        return matches

splash/models.py

@@ -26,7 +26,8 @@ class SplashConfig(ConfigurationModel):
     unaffected_url_paths = models.TextField(
         default='',
         blank=True,
-        help_text="Comma-separated list of URL paths (not including the hostname) which should not be redirected"
+        help_text="Comma-separated list of URL paths (not including the hostname) which should not be redirected. "
+                  "Paths may include wildcards denoted by * (example: /*/student_view)"
     )
     redirect_url = models.URLField(
         default='http://edx.org',

splash/tests.py

@@ -188,3 +188,43 @@ class SplashMiddlewareTestCase(TestCase):
         request = self.build_request(url_path='/my/url/')
         response = self.splash_middleware.process_request(request)
         self.assertEquals(response, None)
+
+    def test_unaffected_wildcard_path(self):
+        """
+        Unaffected wildcard paths should never be redirected - custom value
+        """
+        SplashConfig(
+            enabled=True,
+            unaffected_url_paths='/test1/*, /test2/*/after, /test3/*/before/*/after',
+        ).save()
+
+        # These paths match and should NOT redirect.
+        request = self.build_request(url_path='/test1/')
+        response = self.splash_middleware.process_request(request)
+        self.assertEquals(response, None)
+        request = self.build_request(url_path='/test1/something')
+        response = self.splash_middleware.process_request(request)
+        self.assertEquals(response, None)
+        request = self.build_request(url_path='/test1/something/else')
+        response = self.splash_middleware.process_request(request)
+        self.assertEquals(response, None)
+        request = self.build_request(url_path='/test2/something/after')
+        response = self.splash_middleware.process_request(request)
+        self.assertEquals(response, None)
+        request = self.build_request(url_path='/test3/something/before/something/else/after')
+        response = self.splash_middleware.process_request(request)
+        self.assertEquals(response, None)
+
+        # These paths don't match and should redirect.
+        request = self.build_request(url_path='/test2/')
+        response = self.splash_middleware.process_request(request)
+        self.assert_redirect(response, 'http://edx.org')
+        request = self.build_request(url_path='/test2/after')
+        response = self.splash_middleware.process_request(request)
+        self.assert_redirect(response, 'http://edx.org')
+        request = self.build_request(url_path='/test3/before/after')
+        response = self.splash_middleware.process_request(request)
+        self.assert_redirect(response, 'http://edx.org')
+        request = self.build_request(url_path='/test3/something/before/something/after/more')
+        response = self.splash_middleware.process_request(request)
+        self.assert_redirect(response, 'http://edx.org')