pull #21: some style tweaks, add stream to error event args, test case, example, changelog

CHANGES.md

@@ -1,6 +1,15 @@
 # bunyan Changelog
 
-## bunyan 0.7.1 (not yet released)
+## bunyan 0.8.0 (not yet released)
+
+- [pull #21] Bunyan loggers now re-emit `fs.createWriteStream` error events.
+  By github.com/EvanOxfeld. See "examples/handle-fs-error.js" and
+  "test/error-event.js" for details.
+
+        var log = new Logger({name: 'mylog', streams: [{path: FILENAME}]});
+        log.on('error', function (err, stream) {
+            // Handle error writing to or creating FILENAME.
+        });
 
 - jsstyle'ing (via `make check`)
 

examples/handle-fs-error.js

@@ -0,0 +1,37 @@
+// Example handling as fs error for a Bunyan-created
+// stream.
+
+var fs = require('fs');
+var path = require('path');
+var Logger = require('../lib/bunyan');
+
+var FILENAME = 'handle-fs-error.log';
+var S_IWUSR = 00200; // mask for owner write permission in stat mode
+
+console.warn('- Log file is "%s".', FILENAME);
+if (!path.existsSync(FILENAME)) {
+    console.warn('- Touch log file.');
+    fs.writeFileSync(FILENAME, 'touch\n');
+}
+if (fs.statSync(FILENAME).mode & S_IWUSR) {
+    console.warn('- Make log file read-only.');
+    fs.chmodSync(FILENAME, 0444);
+}
+
+console.warn('- Create logger.')
+var log = new Logger({name: 'handle-fs-error', streams: [{path: FILENAME}]});
+
+log.on('error', function (err) {
+    console.warn('- The logger emitted an error:', err);
+});
+
+console.warn('- Call log.info(...).')
+log.info('info log message');
+console.warn('- Called log.info(...).')
+
+setTimeout(function () {
+    console.warn('- Call log.warn(...).')
+    log.warn('warn log message');
+    console.warn('- Called log.warn(...).')
+}, 1000);
+

lib/bunyan.js

@@ -4,7 +4,7 @@
  * The bunyan logging library for node.js.
  */
 
-var VERSION = '0.7.1';
+var VERSION = '0.8.0';
 
 // Bunyan log format version. This becomes the 'v' field on all log records.
 // `0` is until I release a version '1.0.0' of node-bunyan. Thereafter,
@@ -170,8 +170,6 @@ function resolveLevel(nameOrNum) {
 
 //---- Logger class
 
-Logger.prototype = new EventEmitter;
-
 /**
  * Create a Logger instance.
  *
@@ -242,6 +240,8 @@ function Logger(options, _childOptions, _childSimple) {
     throw new TypeError('invalid options.serializers: must be an object')
   }
 
+  EventEmitter.call(this);
+
   // Fast path for simple child creation.
   if (parent && _childSimple) {
     // `_isSimpleChild` is a signal to stream close handling that this child
@@ -319,8 +319,9 @@ function Logger(options, _childOptions, _childSimple) {
     case 'file':
       if (!s.stream) {
         s.stream = fs.createWriteStream(s.path,
-          {flags: 'a', encoding: 'utf8'}).on('error', function(err) {
-            self.emit('error', err);
+          {flags: 'a', encoding: 'utf8'});
+        s.stream.on('error', function (err) {
+          self.emit('error', err, s);
         });
         if (!s.closeOnExit) {
           s.closeOnExit = true;
@@ -404,6 +405,8 @@ function Logger(options, _childOptions, _childSimple) {
   });
 }
 
+util.inherits(Logger, EventEmitter);
+
 
 /**
  * Create a child logger, typically to add a few log record fields.

test/error-event.test.js

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2012 Trent Mick. All rights reserved.
+ *
+ * Test emission and handling of 'error' event in a logger with a 'path'
+ * stream.
+ */
+
+var test = require('tap').test;
+var Logger = require('../lib/bunyan');
+
+test('error event on log write', function (t) {
+  LOG_PATH = '/this/path/is/bogus.log'
+  var log = new Logger({name: 'error-event', streams: [{path: LOG_PATH}]});
+  t.plan(5);
+  log.on('error', function (err, stream) {
+    t.ok(err, 'got err in error event: ' + err);
+    t.equal(err.code, 'ENOENT', 'error code is ENOENT');
+    t.ok(stream, 'got a stream argument');
+    t.equal(stream.path, LOG_PATH);
+    t.equal(stream.type, 'file');
+    t.end();
+  });
+  log.info('info log message');
+});