add basic inspector module test

spec/fixtures/module/inspector-binding.js

@@ -0,0 +1,84 @@
+const inspector = require('inspector')
+const path = require('path')
+
+// This test case will set a breakpoint 4 lines below
+function debuggedFunction () {
+  let i
+  let accum = 0
+  for (i = 0; i < 5; i++) {
+    accum += i
+  }
+  return accum
+}
+
+let scopeCallback = null
+
+function checkScope (session, scopeId) {
+  session.post('Runtime.getProperties', {
+    'objectId': scopeId,
+    'ownProperties': false,
+    'accessorPropertiesOnly': false,
+    'generatePreview': true
+  }, scopeCallback)
+}
+
+function debuggerPausedCallback (session, notification) {
+  const params = notification['params']
+  const callFrame = params['callFrames'][0]
+  const scopeId = callFrame['scopeChain'][0]['object']['objectId']
+  checkScope(session, scopeId)
+}
+
+function testSampleDebugSession () {
+  let cur = 0
+  const failures = []
+  const expects = {
+    i: [0, 1, 2, 3, 4],
+    accum: [0, 0, 1, 3, 6]
+  }
+  scopeCallback = function (error, result) {
+    if (error) failures.push(error)
+    const i = cur++
+    let v, actual, expected
+    for (v of result['result']) {
+      actual = v['value']['value']
+      expected = expects[v['name']][i]
+      if (actual !== expected) {
+        failures.push(`Iteration ${i} variable: ${v['name']} ` +
+          `expected: ${expected} actual: ${actual}`)
+      }
+    }
+  }
+  const session = new inspector.Session()
+  session.connect()
+  let secondSessionOpened = false
+  const secondSession = new inspector.Session()
+  try {
+    secondSession.connect()
+    secondSessionOpened = true
+  } catch (error) {
+    // expected as the session already exists
+  }
+  session.on('Debugger.paused',
+             (notification) => debuggerPausedCallback(session, notification))
+  let cbAsSecondArgCalled = false
+  session.post('Debugger.enable', () => { cbAsSecondArgCalled = true })
+  session.post('Debugger.setBreakpointByUrl', {
+    'lineNumber': 8,
+    'url': path.resolve(__dirname, __filename),
+    'columnNumber': 0,
+    'condition': ''
+  })
+
+  debuggedFunction()
+  scopeCallback = null
+  session.disconnect()
+  process.send({
+    'cmd': 'assert',
+    'debuggerEnabled': cbAsSecondArgCalled,
+    'secondSessionOpened': secondSessionOpened,
+    'success': (cur === 5) && (failures.length === 0)
+  })
+}
+
+testSampleDebugSession()