Add ability to write reports to file

.gitignore

@@ -4,3 +4,4 @@
 *.iml
 
 coverage/
+test-output.xml

README.md

@@ -68,7 +68,7 @@ file.csslint.opt = {}; // The options you passed to CSSLint
 
 ## Using reporters
 
-Several reporters come built-in to css-lint. To use one of these reporters, pass the name to `csslint.reporter`.
+Several reporters come built-in to css-lint. To use one of these reporters, pass the name to `csslint.reporter`, along with an optional file path. If the file path is included, the report will be written to this location, instead of printed in the console.
 
 For a list of all reporters supported by `csslint`, see the [csslint wiki](https://github.com/CSSLint/csslint/wiki/Command-line-interface#--format).
 
@@ -79,6 +79,15 @@ gulp.task('lint', function() {
     .pipe(csslint.reporter('junit-xml'));
 ```
 
+If you want to print the report to disk instead of output to the console, supply the a second optional file path where the file will be written.
+
+```js
+gulp.task('lint', function() {
+  gulp.files('lib/*.css')
+    .pipe(csslint())
+    .pipe(csslint.reporter('junit-xml', 'csslint-junit-report.xml'));
+```
+
 ### Custom reporters
 
 Custom reporter functions can be passed as `csslint.reporter(reporterFunc)`. The reporter function will be called for each linted file and passed the file object as described above.

index.js

@@ -1,5 +1,6 @@
 'use strict';
 
+var fs = require('fs');
 var gutil = require('gulp-util');
 var through = require('through2');
 var csslint = require('csslint').CSSLint;
@@ -74,7 +75,7 @@ var cssLintPlugin = function(options) {
   });
 };
 
-cssLintPlugin.reporter = function(customReporter) {
+cssLintPlugin.reporter = function(customReporter, filePath) {
   var reporter = csslint.getFormatter('text');
   var builtInReporter = true;
   var output;
@@ -117,7 +118,12 @@ cssLintPlugin.reporter = function(customReporter) {
       if (builtInReporter) {
         output += reporter.endFormat();
 
-        gutil.log(output);
+        if (filePath) {
+          return fs.writeFile(filePath, output, cb);
+        }
+        else {
+          gutil.log(output);
+        }
       }
 
       return cb();

test/main.js

@@ -251,7 +251,7 @@ describe('gulp-csslint', function() {
       stream.end();
     });
 
-    it('should support built-in CSSLint formatters', sinon.test(function(done) {
+    it('should support built-in CSSLint formatters', function(done) {
       var a = 0;
 
       var file = getFile('fixtures/usingImportant.css');
@@ -283,6 +283,45 @@ describe('gulp-csslint', function() {
 
       lintStream.write(file);
       lintStream.end();
-    }));
+    });
+
+    it('should write built-in report to disk', function(done) {
+      var a = 0;
+
+      var file = getFile('fixtures/usingImportant.css');
+      var expected = getContents('expected/checkstyle-xml.xml');
+
+      var lintStream = cssLintPlugin();
+      var reporterStream = cssLintPlugin.reporter('checkstyle-xml', 'test-output.xml');
+
+      sinon.stub(gutil, 'log');
+
+      reporterStream.on('data', function() {
+        ++a;
+      });
+      lintStream.on('data', function(file) {
+        reporterStream.write(file);
+      });
+      lintStream.once('end', function() {
+        reporterStream.end();
+      });
+
+      reporterStream.once('end', function() {
+        a.should.equal(1);
+        sinon.assert.notCalled(gutil.log);
+
+        gutil.log.restore();
+
+        fs.readFile('test-output.xml', function(err, content) {
+          (err === null).should.be.true;
+
+          content.toString().should.equal(expected);
+          done();
+        });
+      });
+
+      lintStream.write(file);
+      lintStream.end();
+    });
   });
 });