Fix: Bind src/dest/symlink to the gulp instance to support esm export…

…s (ref standard-things/esm#797)

index.js

@@ -16,6 +16,9 @@ function Gulp() {
   this.registry = this.registry.bind(this);
   this.tree = this.tree.bind(this);
   this.lastRun = this.lastRun.bind(this);
+  this.src = this.src.bind(this);
+  this.dest = this.dest.bind(this);
+  this.symlink = this.symlink.bind(this);
 }
 util.inherits(Gulp, Undertaker);
 

test/index.test.js

@@ -0,0 +1,60 @@
+'use strict';
+
+var expect = require('expect');
+
+var gulp = require('../');
+
+describe('gulp', function() {
+
+  describe('hasOwnProperty', function() {
+    it('src', function(done) {
+      expect(gulp.hasOwnProperty('src')).toEqual(true);
+      done();
+    });
+
+    it('dest', function(done) {
+      expect(gulp.hasOwnProperty('dest')).toEqual(true);
+      done();
+    });
+
+    it('symlink', function(done) {
+      expect(gulp.hasOwnProperty('symlink')).toEqual(true);
+      done();
+    });
+
+    it('watch', function(done) {
+      expect(gulp.hasOwnProperty('watch')).toEqual(true);
+      done();
+    });
+
+    it('task', function(done) {
+      expect(gulp.hasOwnProperty('task')).toEqual(true);
+      done();
+    });
+
+    it('series', function(done) {
+      expect(gulp.hasOwnProperty('series')).toEqual(true);
+      done();
+    });
+
+    it('parallel', function(done) {
+      expect(gulp.hasOwnProperty('parallel')).toEqual(true);
+      done();
+    });
+
+    it('tree', function(done) {
+      expect(gulp.hasOwnProperty('tree')).toEqual(true);
+      done();
+    });
+
+    it('lastRun', function(done) {
+      expect(gulp.hasOwnProperty('lastRun')).toEqual(true);
+      done();
+    });
+
+    it('registry', function(done) {
+      expect(gulp.hasOwnProperty('registry')).toEqual(true);
+      done();
+    });
+  });
+});