Fix(routing): add protections against malformed data

common/app/routes/challenges/utils.js

@@ -1,5 +1,6 @@
 import { compose } from 'redux';
 import { bonfire, html, js } from '../../utils/challengeTypes';
+import protect from '../../utils/empty-protector';
 
 export function encodeScriptTags(value) {
   return value
@@ -78,19 +79,6 @@ export function loggerToStr(args) {
     .reduce((str, arg) => str + arg + '\n', '');
 }
 
-export function getFirstChallenge(
-  { superBlock, block, challenge },
-  result
-) {
-  return challenge[
-    block[
-      superBlock[
-        result[0]
-      ].blocks[0]
-    ].challenges[0]
-  ];
-}
-
 export function getNextChallenge(
   current,
   entities,
@@ -285,20 +273,6 @@ export function getMouse(e, [dx, dy]) {
   return [pageX - dx, pageY - dy];
 }
 
-const emptyProtector = {
-  blocks: [],
-  challenges: []
-};
-// protect against malformed data
-function protect(block) {
-  // if no block or block has no challenges or blocks
-  // use protector
-  if (!block || !(block.challenges || block.blocks)) {
-    return emptyProtector;
-  }
-  return block;
-}
-
 // interface Node {
 //   isHidden: Boolean,
 //   children: Void|[ ...Node ],

common/app/utils/empty-protector.js

@@ -0,0 +1,13 @@
+const emptyProtector = {
+  blocks: [],
+  challenges: []
+};
+// protect against malformed map data
+// protect(block: { challenges: [], block: [] }|Void) => block|emptyProtector
+export default function protect(block) {
+  // if no block or block has no challenges or blocks
+  if (!block || !(block.challenges || block.blocks)) {
+    return emptyProtector;
+  }
+  return block;
+}

common/utils/get-first-challenge.js

@@ -0,0 +1,44 @@
+import emptyProtector from '../app/utils/empty-protector';
+
+export function checkMapData(
+  {
+    entities: {
+      challenge,
+      block,
+      superBlock,
+      challengeIdToName
+    },
+    result
+  }
+) {
+  if (
+    !challenge ||
+    !block ||
+    !superBlock ||
+    !challengeIdToName ||
+    !result ||
+    !result.length
+  ) {
+    throw new Error(
+      'entities not found, db may not be properly seeded. Crashing hard'
+    );
+  }
+}
+// getFirstChallenge(
+//   map: {
+//     entities: { challenge: Object, block: Object, superBlock: Object },
+//     result: [...superBlockDashedName: String]
+//   }
+// ) => Challenge|Void
+export function getFirstChallenge({
+  entities: { superBlock, block, challenge },
+  result
+}) {
+  return challenge[
+    emptyProtector(block[
+      emptyProtector(superBlock[
+        result[0]
+      ]).blocks[0]
+    ]).challenges[0]
+  ];
+}

server/boot/challenge.js

@@ -1,11 +1,15 @@
 import _ from 'lodash';
-// import { Observable, Scheduler } from 'rx';
 import debug from 'debug';
 import accepts from 'accepts';
+import dedent from 'dedent';
 
 import { ifNoUserSend } from '../utils/middleware';
 import { cachedMap } from '../utils/map';
 import createNameIdMap from '../../common/utils/create-name-id-map';
+import {
+  checkMapData,
+  getFirstChallenge
+} from '../../common/utils/get-first-challenge';
 
 const log = debug('fcc:boot:challenges');
 
@@ -274,40 +278,34 @@ export default function(app) {
         result,
         entities: createNameIdMap(entities)
       }))
-      .map(({
-        result,
-        entities: {
-          challenge: challengeMap,
-          block: blockMap,
-          superBlock: superBlockMap,
-          challengeIdToName
-        }
-      }) => {
+      .map(map => {
+        checkMapData(map);
+        const {
+          entities: { challenge: challengeMap, challengeIdToName }
+        } = map;
         let finalChallenge;
         const dashedName = challengeIdToName[user && user.currentChallengeId];
         finalChallenge = challengeMap[dashedName];
-        if (
-          !challengeMap ||
-          !blockMap ||
-          !superBlockMap ||
-          !result ||
-          !result.length
-        ) {
-          throw new Error(
-            'entities not found, db may not be properly seeded. Crashing hard'
-          );
-        }
         // redirect to first challenge
         if (!finalChallenge) {
-          finalChallenge = challengeMap[
-            block[
-              superBlockMap[
-                result[0]
-              ].blocks[0]
-            ].challenges[0]
-          ];
+          finalChallenge = getFirstChallenge(map);
         }
         const { block, dashedName: finalDashedName } = finalChallenge || {};
+        if (!finalDashedName || !block) {
+          // this should normally not be hit if database is properly seeded
+          console.error(new Error(dedent`
+            Attemped to find '${dashedName}'
+            from '${user && user.currentChallengeId || 'no challenge id found'}'
+            but came up empty.
+            db may not be properly seeded.
+          `));
+          if (dashedName) {
+            // attempt to find according to dashedName
+            return `/challenges/${dashedName}`;
+          } else {
+            return null;
+          }
+        }
         return `/challenges/${block}/${finalDashedName}`;
       })
       .subscribe(