added integration with source-map-support for integration with sourcemaps

Style updates, changelog, etc. Fixes #122

AUTHORS

@@ -18,3 +18,4 @@ Andrei Neculau (https://github.com/andreineculau)
 Mihai Tomescu (https://github.com/matomesc)
 Daniel Juhl (https://github.com/danieljuhl)
 Chris Barber (https://github.com/cb1kenobi)
+Manuel Schneider (https://github.com/manuelschneider)

CHANGES.md

@@ -8,6 +8,11 @@ Known issues:
 
 ## bunyan 1.3.1 (not yet released)
 
+- [pull #122] Source Map support for caller line position for [the "src"
+  field](https://github.com/trentm/node-bunyan#src). This could be interesting
+  for [CoffeeScript](http://coffeescript.org/documentation/docs/sourcemap.html)
+  users of Bunyan. By Manuel Schneider.
+
 - [issue #164] Ensure a top-level `level` given in `bunyan.createLogger`
   is *used* for given `streams`. For example, ensure that the following
   results in the stream having a DEBUG level:

lib/bunyan.js

@@ -50,6 +50,12 @@ try {
 var isBrowser = function () {
         return typeof (window) !== 'undefined' && this === window; }();
 
+try {
+    var sourceMapSupport = require("source-map-support");
+} catch (_) {
+    sourceMapSupport = null;
+}
+
 
 
 //---- Internal support stuff
@@ -126,8 +132,12 @@ function getCaller3Info() {
     var savePrepare = Error.prepareStackTrace;
     Error.stackTraceLimit = 3;
     Error.captureStackTrace(this, getCaller3Info);
+
     Error.prepareStackTrace = function (_, stack) {
         var caller = stack[2];
+        if (sourceMapSupport) {
+            caller = sourceMapSupport.wrapCallSite(caller);
+        }
         obj.file = caller.getFileName();
         obj.line = caller.getLineNumber();
         var func = caller.getFunctionName();