add async scope tracking as an official feature enabled by default

docs/test.ts

@@ -39,9 +39,9 @@ tracer.init({
   analytics: true,
   env: 'test',
   runtimeMetrics: true,
+  trackAsyncScope: false,
   experimental: {
-    b3: true,
-    thenables: true
+    b3: true
   },
   hostname: 'agent',
   logger: {

index.d.ts

@@ -230,6 +230,12 @@ export declare interface TracerOptions {
    */
   runtimeMetrics?: boolean
 
+  /**
+   * Whether to track the scope of async functions. This is needed for async/await to work with non-native promises (thenables). Only disable this if you are sure only native promises are used with async/await.
+   * @default true
+   */
+  trackAsyncScope?: boolean
+
   /**
    * Experimental features can be enabled all at once by using true or individually using key / value pairs.
    * @default {}
@@ -241,8 +247,6 @@ export declare interface TracerOptions {
      * @default false
      */
     exporter?: 'log' | 'browser' | 'agent'
-
-    thenables?: boolean
   };
 
   /**

package.json

@@ -89,7 +89,7 @@
     "get-port": "^3.2.0",
     "graphql": "0.13.2",
     "mocha": "^5.2.0",
-    "nock": "^9.6.1",
+    "nock": "^11.3.3",
     "node-abi": "^2.8.0",
     "nyc": "^14.1.1",
     "prebuildify": "^2.11.0",

packages/.eslintrc.json

@@ -9,7 +9,6 @@
     "expect": true,
     "sinon": true,
     "proxyquire": true,
-    "nock": true,
     "wrapIt": true,
     "withVersions": true
   },

packages/dd-trace/src/config.js

@@ -53,10 +53,10 @@ class Config {
       port: String(coalesce(dogstatsd.port, platform.env('DD_DOGSTATSD_PORT'), 8125))
     }
     this.runtimeMetrics = String(runtimeMetrics) === 'true'
+    this.trackAsyncScope = options.trackAsyncScope !== false
     this.experimental = {
       b3: !(!options.experimental || !options.experimental.b3),
-      exporter: options.experimental && options.experimental.exporter,
-      thenables: !(!options.experimental || !options.experimental.thenables)
+      exporter: options.experimental && options.experimental.exporter
     }
     this.reportHostname = String(reportHostname) === 'true'
     this.scope = process.env.DD_CONTEXT_PROPAGATION === 'false' ? scopes.NOOP : scope

packages/dd-trace/src/scope/async_hooks.js

@@ -18,7 +18,7 @@ class Scope extends Base {
 
     singleton = this
 
-    this._thenables = config.experimental.thenables
+    this._trackAsyncScope = config.trackAsyncScope
     this._current = null
     this._spans = Object.create(null)
     this._types = Object.create(null)
@@ -62,12 +62,17 @@ class Scope extends Base {
   }
 
   _exit (span) {
-    this._thenables && this._await(span)
+    this._trackAsyncScope && this._await(span)
     this._current = span
     this._stack[this._depth] = null
     this._depth--
   }
 
+  _exitNative () {
+    this._current = null
+    this._promises[0] = false
+  }
+
   _await (span) {
     if (!this._promises[this._depth]) return
 
@@ -106,12 +111,13 @@ class Scope extends Base {
     platform.metrics().increment('async.resources')
     platform.metrics().increment('async.resources.by.type', `resource_type:${type}`)
 
-    if (this._thenables && type === 'PROMISE') {
+    if (this._trackAsyncScope && type === 'PROMISE') {
       this._initPromise()
     }
   }
 
   _before (asyncId) {
+    this._depth === 0 && this._exitNative()
     this._enter(this._spans[asyncId])
   }
 

packages/dd-trace/test/.eslintrc.json

@@ -9,7 +9,6 @@
     "expect": true,
     "sinon": true,
     "proxyquire": true,
-    "nock": true,
     "wrapIt": true,
     "withVersions": true
   },

packages/dd-trace/test/config.spec.js

@@ -27,6 +27,7 @@ describe('Config', () => {
     expect(config).to.have.property('flushInterval', 2000)
     expect(config).to.have.property('sampleRate', 1)
     expect(config).to.have.property('runtimeMetrics', false)
+    expect(config).to.have.property('trackAsyncScope', true)
     expect(config).to.have.deep.property('tags', {})
     expect(config).to.have.property('plugins', true)
     expect(config).to.have.property('env', undefined)
@@ -35,7 +36,6 @@ describe('Config', () => {
     expect(config).to.have.property('apiKey', undefined)
     expect(config).to.have.property('appKey', undefined)
     expect(config).to.have.nested.property('experimental.b3', false)
-    expect(config).to.have.nested.property('experimental.thenables', false)
   })
 
   it('should initialize from the default service', () => {
@@ -116,14 +116,14 @@ describe('Config', () => {
       tags,
       flushInterval: 5000,
       runtimeMetrics: true,
+      trackAsyncScope: false,
       reportHostname: true,
       plugins: false,
       scope: 'noop',
       apiKey: '123',
       appKey: '456',
       experimental: {
-        b3: true,
-        thenables: true
+        b3: true
       }
     })
 
@@ -141,6 +141,7 @@ describe('Config', () => {
     expect(config.tags).to.have.property('foo', 'bar')
     expect(config).to.have.property('flushInterval', 5000)
     expect(config).to.have.property('runtimeMetrics', true)
+    expect(config).to.have.property('trackAsyncScope', false)
     expect(config).to.have.property('reportHostname', true)
     expect(config).to.have.property('plugins', false)
     expect(config).to.have.property('scope', 'noop')
@@ -150,7 +151,6 @@ describe('Config', () => {
       'foo': 'bar'
     })
     expect(config).to.have.nested.property('experimental.b3', true)
-    expect(config).to.have.nested.property('experimental.thenables', true)
   })
 
   it('should initialize from the options with url taking precedence', () => {

packages/dd-trace/test/platform/node/index.spec.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const nock = require('nock')
 const semver = require('semver')
 
 wrapIt()

packages/dd-trace/test/scope/async_hooks.spec.js

@@ -91,7 +91,7 @@ describe('Scope (async_hooks)', () => {
 
     beforeEach(() => {
       thenable = {
-        then: () => {}
+        then: onFulfill => onFulfill()
       }
 
       test = async () => {
@@ -155,6 +155,23 @@ describe('Scope (async_hooks)', () => {
         scope.activate(span, () => test())
       })
     })
+
+    it('should use the active span when using nested awaits', async () => {
+      return scope.activate(span, async () => {
+        await thenable
+
+        thenable.then = (onFulfill, onReject) => {
+          try {
+            expect()
+            onFulfill()
+          } catch (e) {
+            onReject(e)
+          }
+        }
+
+        await thenable
+      })
+    })
   })
 
   testScope(() => scope)

packages/dd-trace/test/setup/core.js

@@ -4,7 +4,6 @@ const sinon = require('sinon')
 const chai = require('chai')
 const sinonChai = require('sinon-chai')
 const proxyquire = require('../proxyquire')
-const nock = require('nock')
 const semver = require('semver')
 const platform = require('../../src/platform')
 const node = require('../../src/platform/node')
@@ -13,17 +12,14 @@ const agent = require('../plugins/agent')
 const externals = require('../plugins/externals.json')
 
 const asyncHooksScope = new AsyncHooksScope({
-  experimental: {
-    thenables: true
-  }
+  trackAsyncScope: true
 })
 
 chai.use(sinonChai)
 
 global.sinon = sinon
 global.expect = chai.expect
 global.proxyquire = proxyquire
-global.nock = nock
 global.wrapIt = wrapIt
 global.withVersions = withVersions