add runtime safety checks

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 
 
+### 1.0.9 (2016-06-16)
+- Polish: add runtime safety checks for re-assigning bound objects and arrays.
+
+
 ### 1.0.8 (2016-06-16)
 - Fix: edge case in array index setter which would not insert a new node if needed.
 

benchmark/dbmonster/index.html

@@ -30,7 +30,7 @@
   </table>
 </template>
 <script src="ENV.js"></script>
-<script src="../../dist/simulacra.js"></script>
+<script src="http://simulacra.js.org/simulacra.min.js"></script>
 <script src="http://localvoid.github.io/perf-monitor/0.1/perf-monitor.js"></script>
 <script>
 perfMonitor.startFPSMonitor()

lib/bind_keys.js

@@ -3,6 +3,7 @@
 var processNodes = require('./process_nodes')
 var keyMap = require('./key_map')
 
+var hasBindingsKey = keyMap.hasBindings
 var hasDefinitionKey = keyMap.hasDefinition
 var isBoundToParentKey = keyMap.isBoundToParent
 var hasMutatorsKey = keyMap.hasMutators
@@ -36,6 +37,11 @@ function bindKeys (scope, obj, def, parentNode, path) {
     throw new TypeError(
       'Invalid type of value "' + obj + '", object expected.')
 
+  if (obj[hasBindingsKey])
+    throw new Error('Can not re-assign bound object.')
+
+  Object.defineProperty(obj, hasBindingsKey, { value: true })
+
   for (i = 0, j = defKeys.length; i < j; i++) bindKey(defKeys[i])
 
   function bindKey (key) {
@@ -91,7 +97,10 @@ function bindKeys (scope, obj, def, parentNode, path) {
       value = isArray ? x : [ x ]
 
       // Assign custom mutator methods on the array instance.
-      if (isArray && !value[hasMutatorsKey]) {
+      if (isArray) {
+        if (value[hasMutatorsKey]) throw new Error(
+          'Can not re-assign bound array on field "' + key + '".')
+
         Object.defineProperty(value, hasMutatorsKey, { value: true })
 
         // These mutators preserve length.
@@ -108,7 +117,8 @@ function bindKeys (scope, obj, def, parentNode, path) {
         value.splice = splice
 
         // Handle array index assignment.
-        for (i = 0, j = value.length; i < j; i++) defineIndex(value, i)
+        for (i = 0, j = value.length; i < j; i++)
+          defineIndex(value, i)
       }
 
       // Handle rendering to the DOM. This algorithm tries to batch insertions

lib/index.js

@@ -73,7 +73,6 @@ function simulacra (obj, def) {
     'The first position of top-level must be a Node or a CSS selector string.')
 
   ensureNodes(this, def[0], def[1])
-  Object.defineProperty(obj, hasBindingsKey, { value: true })
   node = processNodes(this, def[0].cloneNode(true), def[1])
 
   path = []

package.json

@@ -1,7 +1,7 @@
 {
   "name": "simulacra",
   "description": "One-way data binding for web applications.",
-  "version": "1.0.8",
+  "version": "1.0.9",
   "license": "MIT",
   "author": {
     "email": "0x8890@airmail.cc",
@@ -35,6 +35,7 @@
     "domino": "^1.0.25",
     "eslint": "^2.11.1",
     "eslint-config-boss": "^1.0.3",
+    "fs-extra": "^0.30.0",
     "highlight.js": "^9.4.0",
     "html-minifier": "^2.1.3",
     "istanbul": "^0.4.3",

website/build.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const fs = require('fs')
+const fs = require('fs-extra')
 const path = require('path')
 const domino = require('domino')
 const simulacra = require('../lib')
@@ -99,6 +99,15 @@ postcss([ atImport, cssnext, cssnano() ])
 fs.writeFileSync(path.join(outputPath, 'CNAME'), CNAME)
 
 
+// Copy benchmarks folder
+// ======================
+
+fs.copySync(
+  path.join(__dirname, '../benchmark/dbmonster'),
+  path.join(outputPath, 'dbmonster'),
+  { clobber: true })
+
+
 // Done!
 // =====