Create onError hook for custom logging and notifications

README.md

@@ -39,6 +39,17 @@ b.plugin(errorify, /* errorify options */);
 
 * `replacer` _(optional)_ is a function that takes an error as its first argument, and returns a string that will be used as the output bundle.
 
+* `onError` _(optional)_ is a function that takes an error as its first argument and is used to override the default handler which simply logs to `stderr`. This option is intended to be used for logging and notification purposes. Example:
+
+```js
+var colors = require('colors/safe');
+var notifier = require('node-notifier');
+var errorHandler = function(err) {
+  console.error(colors.red('Build broken. Error:'), err.message);
+  notifier.notify({ title: 'Browserify build error', message: err.message });
+b.plugin(errorify, { onError: errorHandler });
+```
+
 ### CLI
 
 After installing `errorify` as a local devDependency, you can use the `--plugin` or `-p` option like so:

errorify.js

@@ -5,15 +5,16 @@ var stream = require('stream');
 module.exports = function errorify(b, opts) {
   var bundle = b.bundle;
   var replacer = opts && opts.replacer || defaultReplacer;
+  var errorHandler = opts && opts.onError || defaultErrorLogger;
+
   b.bundle = function(cb) {
     var output = new stream.Transform();
     output._transform = function(chunk, enc, callback) {
       callback(null, chunk);
     };
     var pipeline = bundle.call(b, cb);
     pipeline.on('error', function(err) {
-      // module-deps likes to emit each error
-      console.error('errorify: %s', err);
+      errorHandler(err);
     });
     pipeline.once('error', function(err) {
       output.push(replacer(err));
@@ -83,3 +84,8 @@ function normalizeError(err) {
 function defaultReplacer(err) {
   return '!' + template + '(' + JSON.stringify(normalizeError(err)) + ')';
 }
+
+function defaultErrorLogger(err) {
+  // module-deps likes to emit each error
+  console.error('errorify: %s', err);
+}

package.json

@@ -26,6 +26,7 @@
     "browserify": "^11.0.1",
     "concat-stream": "^1.4.7",
     "tap": "^1.3.2",
+    "std-mocks": "^1.0.1",
     "through2": "^0.6.3"
   }
 }

test/errorify-test.js

@@ -2,6 +2,7 @@
 
 var browserify = require('browserify');
 var concat = require('concat-stream');
+var stdMocks = require('std-mocks');
 var test = require('tap').test;
 var through = require('through2');
 var vm = require('vm');
@@ -175,5 +176,31 @@ test('errorify', function(t) {
     }));
   });
 
+  t.test('default error logger is called by default', function(t) {
+    t.plan(1);
+    stdMocks.use({ stdout: false, stderr: true }); // only mock stderr
+
+    var b = browserify('./test/fixtures/bad-syntax-entry.js');
+    b.plugin(errorify);
+    b.bundle().pipe(concat(function(src) {
+      stdMocks.restore();
+      var output = stdMocks.flush();
+      t.assert(output.stderr.length === 1); // stderr should have one output
+    }));
+  });
+
+  t.test('errorify calls user-provided handler', function(t) {
+    t.plan(1);
+    var b = browserify('./test/fixtures/bad-syntax-entry.js');
+
+    var isCalled = false;
+    var customLogger = function(err) { isCalled = true; }
+    b.plugin(errorify, { onError: customLogger });
+
+    b.bundle().pipe(concat(function(src) {
+      t.assert(isCalled);
+    }));
+  });
+
   t.end();
 });