Add support for processing single files for interop with gulp-watch

README.md

@@ -158,6 +158,23 @@ gulp.task('compass', function() {
 });
 ```
 
+### Usage with gulp-watch
+
+```javascript
+var compass = require('gulp-compass'),
+  watch = require('gulp-watch');
+
+gulp.task('compass', function() {
+  return watch('./src/*.scss')
+    .pipe(compass.singleFile({
+      css: 'app/assets/css',
+      sass: 'app/assets/sass',
+      image: 'app/assets/images'
+    }))
+    .pipe(gulp.dest('app/assets/temp'));
+});
+```
+
 ## Configuration
 
 ### Configuration Options

lib/index.js

@@ -6,6 +6,8 @@ var callCounter = require('./callCounter');
 var through = require('through2');
 var gutil = require('gulp-util');
 var path = require('path');
+var source = require('vinyl-source-stream');
+var eventStream = require('event-stream');
 
 // Consts
 var PLUGIN_NAME = 'gulp-compass';
@@ -77,3 +79,32 @@ module.exports = function(opt) {
 
   return through.obj(collectNames, compile);
 };
+
+/**
+ * Run compass on single sass files as they come down the stream.
+ *
+ * The gulp-compass plugin collects all files and runs compass on them when the
+ * stream is over, but the stream is never over when watching.
+ */
+module.exports.singleFile = function(opt) {
+
+  return eventStream.map(function(file, callback) {
+
+    var result;
+
+    var stream = source(file.relative)
+      .pipe(module.exports(opt))
+      .on('data', function(data) {
+        result = data;
+      })
+      .on('end', function() {
+        callback(null, result);
+      });
+
+    stream.write(file);
+
+    stream.end();
+
+  });
+
+};

package.json

@@ -25,8 +25,10 @@
   },
   "homepage": "https://github.com/appleboy/gulp-compass",
   "dependencies": {
+    "event-stream": "^3.3.2",
     "gulp-util": "^3.0.4",
     "through2": "^0.6.5",
+    "vinyl-source-stream": "^1.1.0",
     "which": "^1.1.1"
   },
   "devDependencies": {