Fix bunyan -p ... (i.e. DTrace integration) on node 4.x and 5.x

This never worked with node >0.x because of faulty logic determining
`nodeSpawnSupportsStdio` -- attempting to compare with, e.g.,
`Number('v1')`.

Fixes #370

CHANGES.md

@@ -8,6 +8,8 @@ Known issues:
 
 ## 1.8.0 (not yet released)
 
+- [issue #370] Fix `bunyan -p ...` (i.e. DTrace integration) on node
+  4.x and 5.x.
 - [issue #329, pull #330] Update the 'rotating-file' stream to do a file
   rotation on initialization if the mtime on the file path indicates the
   last rotation time was missed -- i.e. if the app wasn't running at the

bin/bunyan

@@ -35,9 +35,8 @@ try {
 
 //---- globals and constants
 
-var nodeSpawnSupportsStdio = (
+var nodeVer = process.versions.node.split('.').map(Number);
-    Number(process.version.split('.')[0]) >= 0 ||
+var nodeSpawnSupportsStdio = (nodeVer[0] > 0 || nodeVer[1] >= 8);
-    Number(process.version.split('.')[1]) >= 8);
 
 // Internal debug logging via `console.warn`.
 var _DEBUG = false;
@@ -1555,7 +1554,6 @@ function main(argv) {
     var stylize = (opts.color ? stylizeWithColor : stylizeWithoutColor);
 
     // Pager.
-    var nodeVer = process.versions.node.split('.').map(Number);
     var paginate = (
         process.stdout.isTTY &&
         process.stdin.isTTY &&
@@ -1655,7 +1653,6 @@ if (require.main === module) {
     // We override the `process.stdout.end` guard that core node.js puts in
     // place. The real fix is that `.end()` shouldn't be called on stdout
     // in node core. Node v0.6.9 fixes that. Only guard for v0.6.0..v0.6.8.
-    var nodeVer = process.versions.node.split('.').map(Number);
     if ([0, 6, 0] <= nodeVer && nodeVer <= [0, 6, 8]) {
         var stdout = process.stdout;
         stdout.end = stdout.destroy = stdout.destroySoon = function () {

test/dtrace.test.js

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 Trent Mick. All rights reserved.
+ * Copyright 2016 Trent Mick
  *
  * If available, test dtrace support.
  */
@@ -22,7 +22,7 @@ var test = tap4nodeunit.test;
 var dtracePlats = ['sunos', 'darwin', 'freebsd'];
 var runDtraceTests = true;
 try {
-    require('dtrace-provider')
+    require('dtrace-provider');
 } catch (e) {
     console.log('# skip dtrace tests: no dtrace-provider module');
     runDtraceTests = false;
@@ -75,4 +75,48 @@ test('basic dtrace', function (t) {
 });
 
 
+/*
+ * Run a logger that logs a couple records every second.
+ * Then run `bunyan -p PID` to capture.
+ * Let those run for a few seconds to ensure dtrace has time to attach and
+ * capture something.
+ */
+test('bunyan -p', function (t) {
+    var p = spawn('node', [__dirname + '/log-some-loop.js']);
+
+    var bunyanP = spawn('node',
+        [__dirname + '/../bin/bunyan', '-p', String(p.pid), '-0']);
+    var traces = [];
+    bunyanP.stdout.on('data', function (data) {
+        //console.error('BUNYAN -P STDOUT:', data.toString());
+        traces.push(data.toString());
+    });
+    bunyanP.stderr.on('data', function (data) {
+        console.error('BUNYAN -P STDERR:', data.toString());
+    });
+    bunyanP.on('exit', function (code) {
+        traces = traces.join('').split('\n')
+            .filter(function (t) { return t.trim().length })
+            .map(function (t) { return JSON.parse(t) });
+        t.ok(traces.length >= 3, 'got >=3 log records: ' + traces.length);
+        if (traces.length >= 3) {
+            if (traces[0].level !== bunyan.DEBUG) {
+                traces.shift();
+            }
+            t.equal(traces[0].level, bunyan.DEBUG);
+            t.equal(traces[0].foo, 'bar');
+            t.equal(traces[1].level, bunyan.TRACE);
+            t.equal(traces[1].msg, 'hi at trace');
+        }
+        t.end();
+    });
+
+    // Give it a few seconds to ensure we get some traces.
+    setTimeout(function () {
+        p.kill();
+        bunyanP.kill();
+    }, 3000);
+});
+
+
 } /* end of `if (runDtraceTests)` */

test/log-some-loop.js

@@ -0,0 +1,15 @@
+
+// A helper script to log a few times, pause, repeat. We attempt to NOT emit
+// to stdout or stderr because this is used for dtrace testing
+// and we don't want to mix output.
+
+var bunyan = require('../lib/bunyan');
+var log = bunyan.createLogger({
+    name: 'play',
+    serializers: bunyan.stdSerializers
+});
+
+setInterval(function logSome() {
+    log.debug({foo: 'bar'}, 'hi at debug')
+    log.trace('hi at trace')
+}, 1000);