Add gulpfile

gulpfile.js

@@ -0,0 +1,60 @@
+// Imports.
+var gulp = require('gulp');
+var util = require('util');
+var exec = util.promisify(require('child_process').exec);
+var minimist = require('minimist');
+var fs = require('fs');
+
+// Fetch command-line arguments.
+var args = minimist(process.argv.slice(2), {
+  default: {
+    env: process.env.NODE_ENV || 'production',
+    newversion: 'patch'
+  }
+});
+
+/* ----- REUSABLE TASKS ----- */
+
+// Get package version from package.json.
+function getVersion() {
+  var pkg = JSON.parse(fs.readFileSync('./package.json'));
+  return 'v' + pkg.version;
+}
+
+// Merge the specified branch back into master and develop.
+function mergeBranch(branch) {
+  var mergeCmd = 'git merge --no-ff --no-edit ' + branch;
+  return exec('git checkout master && ' + mergeCmd).then(function() {
+    return exec('git checkout develop && ' + mergeCmd);
+  });
+}
+
+/* ----- TASKS ----- */
+
+// Stage a release (bump version and create a 'release/[version]' branch).
+gulp.task('stage-release', function() {
+  var cmd = 'npm --no-git-tag-version version ' + args.newversion;
+  return exec(cmd).then(function() {
+    var version = getVersion();
+    var branch = 'release/' + version;
+
+    var cmd = 'git checkout -b ' + branch + ' && git add -A';
+    cmd += ' && git commit -m "Prepare release ' + version + '"';
+    return exec(cmd);
+  });
+});
+
+// Tag and merge the latest release into master/develop.
+gulp.task('release', function() {
+  var version = getVersion();
+  var branch = 'release/' + version;
+
+  var cmd = 'git checkout ' + branch + ' && npm run build';
+  cmd += ' && git add -A && git commit -m "Build ' + version + '"';
+  cmd += ' && git tag -a ' + version + ' -m "' + version + ' ' + args.tagmessage + '"';
+  return exec(cmd).then(function() {
+    return mergeBranch(branch);
+  }).then(function() {
+    return exec('git branch -d ' + branch);
+  });
+});