From 956734a9b9392b5ed19c7fcfb60275ec0d4ac8ed Mon Sep 17 00:00:00 2001
From: Matthew Collier <collier.matthew@gmail.com>
Date: Wed, 2 Jan 2019 12:40:49 -0500
Subject: [PATCH] Implement route conditional middleware.

---
 lib/index.js | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index 6fce1ab..2cfb8e8 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -190,8 +190,10 @@ function init(callback) {
         return callback();
       }
       if(bedrock.config.express.useSession) {
-        server.use(api.middleware['express-session'](
-          bedrock.config.express.session));
+        server.use(_routeConditionalMiddleware({
+          fn: api.middleware['express-session'](bedrock.config.express.session),
+          routeBlackList: ['/foo']
+        }));
       }
       callback();
     }],
@@ -353,3 +355,26 @@ function _acceptableContent(options) {
     res.status(415).send();
   };
 }
+
+function _routeConditionalMiddleware({fn/*, routeBlackList*/}) {
+  // TODO: this would be passed in and would originate in the bedrock config
+  const routeBlackList = new Set([
+    '/consensus/continuity2017/voters/:voterId/gossip'
+  ]);
+  return function(req, res, next) {
+    // iterate backwards because top level routes are defined near the end
+    // TODO: is there some way to not have to iterate the stack on every
+    // call?  Could the blackListed layers be stored somehow?
+    for(let i = server._router.stack.length - 1; i >= 0; --i) {
+      const layer = server._router.stack[i];
+      if(!layer.route) {
+        continue;
+      }
+      if(routeBlackList.has(layer.route.path) && req.path.match(layer.regexp)) {
+        // blackList match do not execute the provided middeleware `fn`
+        return next();
+      }
+    }
+    fn(req, res, next);
+  };
+}