Fix #510 thanks to @robinvenneman

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 * Drop Node 0.12 support
+* Prevent `TypeError` when a filter is applied on a `null` value [#510](https://github.com/typicode/json-server/issues/510)
 
 ## [0.9.6][2016-03-08]
 

src/server/router/plural.js

@@ -114,9 +114,12 @@ module.exports = (db, name) => {
               const isRange = /_lte$/.test(key) || /_gte$/.test(key)
               const isLike = /_like$/.test(key)
               const path = key.replace(/(_lte|_gte|_ne|_like)$/, '')
+              // get item value based on path
+              // i.e post.title -> 'foo'
               const elementValue = _.get(element, path)
 
-              if (elementValue === undefined) {
+              // Prevent toString() failing on undefined or null values
+              if (elementValue === undefined || elementValue === null) {
                 return
               }
 

test/server/plural.js

@@ -20,7 +20,7 @@ describe('Server', () => {
 
     db.posts = [
       { id: 1, body: 'foo' },
-      { id: 2, body: 'bar' }
+      { id: 2, body: 'bar' },
     ]
 
     db.tags = [
@@ -163,6 +163,16 @@ describe('Server', () => {
         .expect(db.comments)
         .expect(200)
     ))
+
+    // https://github.com/typicode/json-server/issues/510
+    it.only('should not fail with null value', () => {
+      db.posts.push({ id: 99, body: null })
+      return request(server)
+        .get('/posts?body=foo')
+        .expect('Content-Type', /json/)
+        .expect([ db.posts[0] ])
+        .expect(200)
+    })
   })
 
   describe('GET /:resource?q=', () => {