Add prepublishOnly script (#825)

* Add prepublishOnly script

* Use normal function instead of arrow

.gitignore

@@ -4,6 +4,7 @@
 /dist
 /_dev
 /coverage
+/.package.json
 
 # Additional bundles
 /devtools.js

config/prepublish.js

@@ -0,0 +1,22 @@
+const path = require('path').join(__dirname, '..', 'package.json');
+const pkg = require(path);
+
+const UNNECESSARY_KEYS = [
+	'babel',
+	'greenkeeper',
+	'bundlesize',
+	'devDependencies',
+	'eslintConfig'
+];
+
+UNNECESSARY_KEYS.forEach(function (key) {
+	delete pkg[key];
+});
+
+pkg.scripts = {
+	donate: pkg.scripts.donate,
+	postinstall: pkg.scripts.postinstall,
+	postpublish: 'mv -f .package.json package.json'
+};
+
+require('fs').writeFileSync(path, JSON.stringify(pkg, null, 2));

package.json

@@ -32,6 +32,7 @@
     "test:size": "bundlesize",
     "lint": "eslint debug devtools src test",
     "prepublish": "npm run build",
+    "prepublishOnly": "cp package.json .package.json; node config/prepublish.js",
     "smart-release": "npm run build && npm test && git commit -am $npm_package_version && git tag $npm_package_version && git push && git push --tags && npm publish",
     "release": "cross-env npm run smart-release",
     "postinstall": "node ./config/donation-message.js"