use local install of spike if possible

lib/index.js

@@ -7,8 +7,10 @@ const GA = require('universal-analytics')
 const ArgumentParser = require('argparse').ArgumentParser
 const reduce = require('lodash.reduce')
 const pkg = require('../package.json')
-let Spike = require('spike-core') // mocked in tests
+const path = require('path')
+const fs = require('fs')
 let analytics
+let Spike
 
 /**
  * @class CLI
@@ -19,9 +21,6 @@ module.exports = class CLI extends EventEmitter {
   constructor () {
     super()
 
-    const uid = Spike.globalConfig().id // mocked in tests
-    analytics = new GA('UA-79663181-1', uid, { strictCidFormat: false })
-
     this.parser = new ArgumentParser({
       version: pkg.version,
       description: pkg.description,
@@ -50,6 +49,20 @@ module.exports = class CLI extends EventEmitter {
     // null values here
     args = reduce(args, (m, v, k) => { if (v) m[k] = v; return m }, {})
 
+    // try to load up a local spike instance first
+    let spikePath = args.path && path.join(args.path, 'node_modules/spike-core')
+    try {
+      fs.accessSync(spikePath)
+    } catch (_) {
+      spikePath = 'spike-core'
+    }
+
+    if (!Spike) { Spike = require(spikePath) }
+
+    // set up analytics
+    const uid = Spike.globalConfig().id // mocked in tests
+    analytics = new GA('UA-79663181-1', uid, { strictCidFormat: false })
+
     // anonymous analytics for usage data
     analytics.event({ ec: 'cmd', ea: args.fn, ev: JSON.stringify(args) }).send()