fix(apm): add typecheck

Author: dszakallas

lib/agent/metrics/apm/index.js

@@ -113,17 +113,19 @@ ApmMetrics.prototype._nanoToMilli = function (value) {
 
 ApmMetrics.prototype.getEventLoop = function () {
   var stats = eventLoopStats.sense()
+
+  var formattedStats = stats && {
+    max: stats.max,
+    maxUnit: 'ms',
+    min: stats.min,
+    minUnit: 'ms',
+    sum: stats.sum,
+    sumUnit: 'ms',
+    num: stats.num,
+    numUnit: 'pcs'
+  }
   return {
-    stats: {
-      max: stats.max,
-      maxUnit: 'ms',
-      min: stats.min,
-      minUnit: 'ms',
-      sum: stats.sum,
-      sumUnit: 'ms',
-      num: stats.num,
-      numUnit: 'pcs'
-    },
+    stats: formattedStats,
     requests: process._getActiveRequests().length,
     requestsUnit: 'pcs',
     handlers: process._getActiveHandles().length,

lib/agent/metrics/apm/index.spec.js

@@ -103,6 +103,83 @@ describe('The ApmMetrics module', function () {
     })
   })
 
+  it('does not fail when eventLoopStats is not loaded', function () {
+    var activeRequests = 3
+    var activeHandlers = 5
+    var ISOString = 'date-string'
+    var loadAvg = 3
+    var memoryUsed = 24000000
+    var memoryTotal = 12000000
+    var memoryRss = 15000000
+
+    var collectorApi = {
+      sendApmMetrics: this.sandbox.spy()
+    }
+
+    var apmMetrics = ApmMetrics.create({
+      collectorApi: collectorApi,
+      config: {
+        collectInterval: 1
+      }
+    })
+    apmMetrics.lagId = 1
+
+    apmMetrics.gc = {
+      time: 6700000,
+      scavenge: 3,
+      marksweep: 1
+    }
+
+    this.sandbox.stub(eventLoopStats, 'sense')
+    this.sandbox.stub(process, '_getActiveRequests', function () {
+      return new Array(activeRequests)
+    })
+    this.sandbox.stub(process, '_getActiveHandles', function () {
+      return new Array(activeHandlers)
+    })
+    this.sandbox.stub(process, 'memoryUsage', function () {
+      return {
+        rss: memoryRss,
+        heapTotal: memoryTotal,
+        heapUsed: memoryUsed
+      }
+    })
+    this.sandbox.stub(Date.prototype, 'toISOString', function () {
+      return ISOString
+    })
+    this.sandbox.stub(os, 'loadavg', function () {
+      return [loadAvg]
+    })
+
+    this.sandbox.stub(apmMetrics, 'cpuCount', 2)
+
+    apmMetrics.sendMetrics()
+
+    expect(collectorApi.sendApmMetrics).to.be.calledWith({
+      memory: {
+        used: 22,
+        usedUnit: 'MB',
+        total: 11,
+        totalUnit: 'MB',
+        rss: 14,
+        rssUnit: 'MB'
+      },
+      cpu: {
+        utilization: 150,
+        utilizationUnit: 'pct'
+      },
+      gc: {
+        time: 6,
+        timeUnit: 'ms',
+        scavenge: 3,
+        scavengeUnit: 'pcs',
+        marksweep: 1,
+        marksweepUnit: 'pcs'
+      },
+      timestamp: ISOString
+    })
+  })
+
   it('skips utilization if running in VM', function () {
     var collectorApi = {
       sendApmMetrics: this.sandbox.spy()