Add support for Node.js v6

.travis.yml

@@ -3,5 +3,6 @@ node_js:
 - '0.12'
 - '4'
 - '5'
+- '6'
 script:
 - ./bin/run-test.sh -c

lib/v8debugapi.js

@@ -18,7 +18,7 @@
 
 /** @const */ var vm = require('vm');
 /** @const */ var path = require('path');
-/** @const */ //var util = require('util');
+/** @const */ var semver = require('semver');
 
 /** @const */ var state = require('./state.js');
 /** @const */ var logModule = require('@google/cloud-diagnostics-common').logger;
@@ -61,29 +61,23 @@ module.exports.create = function(logger_, config_, fileStats_) {
   var breakpoints = {};
   var listeners = {};
   var numBreakpoints = 0;
-  var usePermanentListener = true;
+  // Before V8 4.5, having a debug listener active disables optimization. To
+  // deal with this we only activate the listener when there is a breakpoint
+  // active, and remote it as soon as the snapshot is taken. Furthermore, 4.5
+  // changes the API such that Debug.scripts() crashes unless a listener is
+  // active. We use a permanent listener on V8 4.5+.
+  var v8_version = /(\d+\.\d+\.\d+)\.\d+/.exec(process.versions.v8);
+  if (!v8_version || v8_version.length < 2) {
+    return null;
+  }
+  var usePermanentListener = semver.satisfies(v8_version[1], '>=4.5');
 
   // Node.js v0.11+ have the runInDebugContext method that can be used to fetch
   // the API object.
   if (!vm.runInDebugContext) {
     return null;
   }
 
-  // Before V8 4.6, having a debug listener active disables optimization. To
-  // deal with this we only activate the listener when there is a breakpoint
-  // active, and remote it as soon as the snapshot is taken. Furthermore, 4.6
-  // changes the API such that Debug.scripts() crashes unless a listener is
-  // active. We use a permanent listener on V8 4.6+.
-  var result = /(\d+)\.(\d+)\.\d+\.\d+/.exec(process.versions.v8);
-  if (!result) {
-    // malformed V8 version?
-    return null;
-  }
-  if (parseInt(result[1], 10) < 4 ||
-      parseInt(result[2], 10) < 5) {
-    usePermanentListener = false;
-  }
-
   v8 = vm.runInDebugContext('Debug');
   logger = logger_;
   config = config_;