Refactor

src/routes.js

@@ -73,7 +73,13 @@ routes.update = function(req, res, next) {
 // DELETE /:resource/:id
 routes.destroy = function(req, res, next) {
   low(req.params.resource).remove(+req.params.id)
-  utils.clean()
+  
+  // Remove dependents documents
+  var removable = utils.getRemovable(low.db)
+
+  _(removable).each(function(item) {
+    low(item[0]).remove(item[1]);
+  })
 
   res.send(204)
 }

src/utils.js

@@ -28,33 +28,31 @@ function createId(coll) {
   }
 }
 
-// Removes empty relations
-function clean() {
-  var toBeRemoved = []
 
-  _(low.db).each(function(coll, collName) {
+// Returns document that are have unsatisfied relations
+// Example: comment that references a post that doesn't exist
+function getRemovable(db) {
+  var removable = []
+
+  _(db).each(function(coll, collName) {
     _(coll).each(function(doc) {
       _(doc).each(function(value, key) {
         if (/Id$/.test(key)) {
-          var reference = _.pluralize(key.slice(0, - 2))
-          if (!_.isUndefined(low(reference).get(doc[key]).value())) {
-            toBeRemoved.push({
-              collName: collName,
-              id: doc.id
-            })
+          var refName = _.pluralize(key.slice(0, - 2))
+          var ref     = _.findWhere(db[refName], {id: value})
+          if (_.isUndefined(ref)) {
+            removable.push([collName, doc.id])
           }
         }
       })
     })
   })
 
-  _(toBeRemoved).each(function(item) {
-    low(item.collName).remove(item.id);
-  })
+  return removable
 }
 
 module.exports = {
   toNative: toNative,
   createId: createId,
-  clean: clean
+  getRemovable: getRemovable
 }

test/server.js

@@ -2,7 +2,6 @@ var request = require('supertest')
 var assert  = require('assert')
 var low     = require('lowdb')
 var server  = require('../src/server')
-var db
 
 describe('Server', function() {
 
@@ -19,6 +18,7 @@ describe('Server', function() {
       {id: 2, published: false, postId: 1},
       {id: 3, published: false, postId: 2},
       {id: 4, published: false, postId: 2},
+      {id: 5, published: false, postId: 2},
     ]
   })
 
@@ -141,7 +141,7 @@ describe('Server', function() {
         .end(function(err, res){
           if (err) return done(err)
           assert.equal(low.db.posts.length, 1)
-          assert.equal(low.db.comments.length, 2)
+          assert.equal(low.db.comments.length, 3)
           done()
         })
     })

test/utils.js

@@ -0,0 +1,31 @@
+var assert = require('assert')
+var utils  = require('../src/utils')
+
+describe('utils', function() {
+  
+  describe('getRemovable', function() {
+
+    it('should return removable documents', function() {
+      
+      var db = {
+        posts: [
+          {id: 1, comment: 1}
+        ],
+        comments: [
+          {id: 1, postId: 1},
+          // Comments below references a post that doesn't exist
+          {id: 2, postId: 2},
+          {id: 3, postId: 2},
+        ]
+      }
+
+      var expected = [
+        ['comments', 2],
+        ['comments', 3]
+      ]
+
+      assert.deepEqual(expected, utils.getRemovable(db))
+
+    })
+  })
+})