logicalparadox · January 8, 2012 07:01 · Jan 8, 2012 · Jan 8, 2012 · Jan 8, 2012
diff --git a/About.md b/About.md
@@ -6,8 +6,6 @@ I am working on a custom error constructor for my [seed](https://github.com/qual
 * When in development, I can easily throw these errors should I need additional feedback on to what is going on.
 * Any addon plugins made can use or extend the custom error type and still satisfy the first two objective with ease.
 
-This is still a work in progress. Comments encouraged. If you fork, please comment on your progress.
-
 [![Screenshot](http://f.cl.ly/items/2s0Z152a2W0A0K3x1m2p/CustomError.png)](http://cl.ly/1V3M1q3W0g422003271a)
 
 Technically inspired by [this post](http://www.devthought.com/2011/12/22/a-string-is-not-an-error/).
diff --git a/customerror.js b/customerror.js
@@ -83,6 +83,6 @@ CustomError.prototype.toJSON = function () {
       name: this.name
     , message: this.message
     , memory: this.memory
-    , stack: this.stackJSON
+    , stack: this._stack
   };
 }
diff --git a/About.md b/About.md
@@ -0,0 +1,13 @@
+# Custom Errors
+
+I am working on a custom error constructor for my [seed](https://github.com/qualiancy/seed) project. I had a few objectives in mind when I started.
+
+* When in production, these errors need to be able to be serialized for logging.
+* When in development, I can easily throw these errors should I need additional feedback on to what is going on.
+* Any addon plugins made can use or extend the custom error type and still satisfy the first two objective with ease.
+
+This is still a work in progress. Comments encouraged. If you fork, please comment on your progress.
+
+[![Screenshot](http://f.cl.ly/items/2s0Z152a2W0A0K3x1m2p/CustomError.png)](http://cl.ly/1V3M1q3W0g422003271a)
+
+Technically inspired by [this post](http://www.devthought.com/2011/12/22/a-string-is-not-an-error/).
diff --git a/customerror.js b/customerror.js
@@ -0,0 +1,88 @@
+var util = require('util');
+
+function colorize (str, color) {
+  var options = {
+      red:      '\u001b[31m'
+    , green:    '\u001b[32m'
+    , yellow:   '\u001b[33m'
+    , blue:     '\u001b[34m'
+    , magenta:  '\u001b[35m'
+    , cyan:     '\u001b[36m'
+    , gray:     '\u001b[90m'
+    , reset:    '\u001b[0m'
+  };
+  return options[color] + str + options.reset;
+};
+
+function pad (str, width) {
+  return Array(width - str.length).join(' ') + str;
+};
+
+module.exports = CustomError;
+
+function CustomError (msg) {
+  Error.call(this);
+
+  // Write our opts to the object
+  this.message = msg;
+  this.name = 'CustomError';
+  this.memory = process.memoryUsage();
+
+  // We need the raw stack so we can make a JSON
+  // object for writing to the logs.
+  var orig = Error.prepareStackTrace;
+  Error.prepareStackTrace = function(_, stack){ return stack; };
+  Error.captureStackTrace(this, arguments.callee);
+  this.__stack = this.stack;
+  Error.prepareStackTrace = orig;
+
+  // Lets make our JSON object.
+  this._stack = [];
+  for (var i = 0; i < this.__stack.length; i ++) {
+    var frame = this.__stack[i];
+    this._stack.push({
+        filename: frame.getFileName()
+      , typename: frame.getTypeName()
+      , linenum: frame.getLineNumber()
+      , funcname: frame.getFunctionName()
+      , method: frame.getMethodName()
+    });
+  }
+
+  // Since we provided our own prepareStackTrace, we need
+  // to provide a new stack getter for display. Lets make
+  // it look better while we are at it.
+  Object.defineProperty(this, 'stack', {
+    get: function () {
+      var buf = [];
+
+      buf.push('');
+      buf.push(pad('', 8) + colorize(this.name, 'red'));
+      buf.push(pad('', 8) + colorize(Array(this.name.length + 1).join('-'), 'gray'));
+      buf.push(pad('', 8) + colorize(this.message, 'magenta'));
+      buf.push(pad('', 8) + colorize((this.memory.heapTotal / 1048576).toFixed(3) + ' MB', 'blue') + colorize(' total ', 'gray'));
+      buf.push(pad('', 8) + colorize((this.memory.heapUsed / 1048576).toFixed(3) + ' MB', 'blue') + colorize(' used  ', 'gray'));
+      buf.push(pad('', 8) + colorize(Array(this.name.length + 1).join('-'), 'gray'));
+      buf.push('');
+
+      this._stack.forEach(function (frame) {
+        buf.push('  ' + colorize(pad(frame.linenum + '', 5), 'blue') + colorize(' ' + frame.filename, 'gray') );
+        buf.push(pad('', 8) + colorize((frame.funcname ? frame.funcname : 'Anonymous'), 'green') + ' ' + colorize('[' + frame.typename + ']', 'yellow'));
+      });
+
+      buf.push('');
+      return buf.join('\n');
+    }
+  });
+}
+
+util.inherits(CustomError, Error);
+
+CustomError.prototype.toJSON = function () {
+  return {
+      name: this.name
+    , message: this.message
+    , memory: this.memory
+    , stack: this.stackJSON
+  };
+}
diff --git a/testerror.js b/testerror.js
@@ -0,0 +1,17 @@
+var CustomError = require('./customerror');
+
+function log (err) {
+  console.error(err);
+}
+
+function a (){
+  b();
+}
+
+function b () {
+  var err = new CustomError('There was a problem doing something in your app.');
+  log(err.toJSON());
+  throw err;
+}
+
+a();