Add gulp buildpack.

buildpack/bin/compile

@@ -9,7 +9,7 @@ bp_dir=$(cd $(dirname $0); cd ..; pwd)
 # Load some convenience functions like status()
 source $bp_dir/bin/common.sh
 
-for pack in node bower; do
+for pack in node bower gulp; do
   if name=$($bp_dir/buildpacks/$pack/bin/detect "$@"); then
     status "Detected ${name}"
     $bp_dir/buildpacks/$pack/bin/compile "$@"

buildpack/buildpacks/gulp/bin/common.sh

@@ -0,0 +1,26 @@
+error() {
+  echo " !     $*" >&2
+  exit 1
+}
+
+status() {
+  echo "-----> $*"
+}
+
+protip() {
+  echo
+  echo "PRO TIP: $*" | indent
+  echo "See https://devcenter.heroku.com/articles/nodejs-support" | indent
+  echo
+}
+
+# sed -l basically makes sed replace and buffer through stdin to stdout
+# so you get updates while the command runs and dont wait for the end
+# e.g. npm install | indent
+indent() {
+  c='s/^/       /'
+  case $(uname) in
+    Darwin) sed -l "$c";; # mac/bsd sed: -l buffers on line boundaries
+    *)      sed -u "$c";; # unix/gnu sed: -u unbuffered (arbitrary) chunks of data
+  esac
+}

buildpack/buildpacks/gulp/bin/compile

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+set -e            # fail fast
+set -o pipefail   # don't ignore exit codes when piping output
+# set -x          # enable debugging
+
+# Configure directories
+build_dir=$1
+cache_dir=$2
+env_dir=$3
+
+bp_dir=$(cd $(dirname $0); cd ..; pwd)
+
+# Load some convenience functions like status() and indent()
+source $bp_dir/bin/common.sh
+
+# Expose user-installed bower
+export PATH=$build_dir/node_modules/.bin:$PATH
+
+# Get gulp version
+gulp_bin=$(which gulp)
+status "Using Gulp from ${gulp_bin#$build_dir/}"
+gulp -v 2>&1 | indent
+
+# Run subsequent node/gulp commands from the build path
+cd $build_dir
+
+status "Building"
+gulp build 2>&1 | indent

buildpack/buildpacks/gulp/bin/detect

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# bin/detect <build-dir>
+
+if [ -f $1/gulpfile.js ]; then
+  echo "Gulp" && exit 0
+else
+  echo "no" && exit 1
+fi