fix test failures due to error middleware ordering

server/src/middleware/csrf.js

@@ -1,3 +1,4 @@
+const assert = require("assert");
 const csrf = require("csurf");
 const mozlog = require("../logging").mozlog("csrf-middleware");
 const { captureRavenException } = require("../ravenclient");
@@ -24,12 +25,10 @@ exports.csrf = function(req, res, next) {
   next();
 };
 
-exports.csrfErrorHandler = function(err, req, res, next) {
-  if (err.code !== "EBADCSRFTOKEN") {
-    next();
-  }
+exports.csrfErrorResponse = function(err, req, res) {
+  assert(err.code === "EBADCSRFTOKEN", "Returning csrf response for non-csrf error code.");
   mozlog.info("bad-csrf", {id: req.ip, url: req.url});
   res.status(403);
   res.type("text");
-  res.send("Bad CSRF Token")
+  res.send("Bad CSRF Token");
 };

server/src/server.js

@@ -30,7 +30,7 @@ const dbschema = require("./dbschema");
 const express = require("express");
 const bodyParser = require('body-parser');
 const contentDisposition = require("content-disposition");
-const { csrf, csrfProtection, csrfErrorHandler } = require("./middleware/csrf");
+const { csrf, csrfProtection, csrfErrorResponse } = require("./middleware/csrf");
 const morgan = require("morgan");
 const linker = require("./linker");
 const { randomBytes } = require("./helpers");
@@ -1064,8 +1064,6 @@ require("./jobs").start();
 
 addRavenErrorHandler(app);
 
-app.use(csrfErrorHandler);
-
 app.use(function(err, req, res, next) {
   if (err.isAppError) {
     let { statusCode, headers, payload } = err.output;
@@ -1087,6 +1085,10 @@ app.use(function(err, req, res, next) {
     res.send(res.message);
     return;
   }
+  if (err.code === "EBADCSRFTOKEN") {
+    csrfErrorResponse(err, req, res);
+    return;
+  }
   errorResponse(res, "General error:", err);
 });