tests: add verification of use of crypto.randomBytes

package.json

@@ -21,7 +21,8 @@
   },
   "license": "ISC",
   "dependencies": {
-    "crypto-js": "^3.1.2-2"
+    "crypto-js": "^3.1.2-2",
+    "sinon": "^1.10.3"
   },
   "devDependencies": {
     "browserify": "^5.9.1",

test/index.js

@@ -1,5 +1,7 @@
 var assert = require('assert')
+var crypto = require('crypto')
 var BIP39 = require('../index.js')
+var sinon = require('sinon')
 
 var wordlists = {
   english: require('../wordlists/en.json'),
@@ -48,7 +50,17 @@ describe('BIP39', function() {
   })
 
   describe('generateMnemonic', function() {
-    it('generates a mnemonic', function() {
+    vectors.english.forEach(function(v, i) {
+      it('works for tests vector ' + i, sinon.test(function() {
+        this.mock(crypto).expects('randomBytes')
+          .exactly(1)
+          .onCall(0).returns(new Buffer(v[0], 'hex'))
+
+        assert.equal(BIP39.generateMnemonic(), v[1])
+      }))
+    })
+
+    it('can vary generated entropy bit length', function() {
       var mnemonic = BIP39.generateMnemonic(96)
       var words = mnemonic.split(' ')