base58check: fix wrapper and tests

test/base58check.js

@@ -1,3 +1,4 @@
+var assert = require('assert')
 var base58check = require('../src/base58check')
 var bs58check = require('bs58check')
 var sinon = require('sinon')
@@ -11,15 +12,15 @@ describe('base58check', function() {
 
   it('wraps bs58check.decode', sinon.test(function() {
     this.mock(bs58check).expects('decode')
-      .once().calledWith(param)
+      .once().calledWith(param).returns('foo')
 
-    base58check.decode(param)
+    assert.equal(base58check.decode(param), 'foo')
   }))
 
   it('wraps bs58check.encode', sinon.test(function() {
     this.mock(bs58check).expects('encode')
-      .once().calledWith(param)
+      .once().calledWith(param).returns('foo')
 
-    base58check.encode(param)
+    assert.equal(base58check.encode(param), 'foo')
   }))
 })