Rework build commands to use correct NODE_ENV for feature flags

package.json

@@ -148,7 +148,7 @@
 		"clean:packages": "rimraf ./packages/*/build ./packages/*/build-module ./packages/*/build-style",
 		"prebuild:packages": "npm run clean:packages && lerna run build && cross-env INCLUDE_PACKAGES=babel-plugin-import-jsx-pragma,postcss-themes,jest-console SKIP_JSX_PRAGMA_TRANSFORM=1 node ./bin/packages/build.js",
 		"build:packages": "cross-env EXCLUDE_PACKAGES=babel-plugin-import-jsx-pragma,jest-console,postcss-themes node ./bin/packages/build.js",
-		"build": "npm run build:packages && cross-env NODE_ENV=production webpack",
+		"build": "npm run build:packages && webpack",
 		"check-engines": "wp-scripts check-engines",
 		"check-licenses": "concurrently \"wp-scripts check-licenses --prod --gpl2\" \"wp-scripts check-licenses --dev\"",
 		"precheck-local-changes": "npm run docs:build",
@@ -169,13 +169,13 @@
 		"lint-pkg-json": "wp-scripts lint-pkg-json ./packages",
 		"lint-css": "wp-scripts lint-style '**/*.scss'",
 		"lint-css:fix": "npm run lint-css -- --fix",
-		"package-plugin": "./bin/build-plugin-zip.sh",
+		"package-plugin": "cross-env NODE_ENV=plugin ./bin/build-plugin-zip.sh",
 		"postinstall": "npm run check-licenses && npm run build:packages",
 		"pot-to-php": "./bin/pot-to-php.js",
 		"precommit": "lint-staged",
-		"publish:check": "npm run build:packages && lerna updated",
-		"publish:dev": "npm run build:packages && lerna publish --npm-tag next",
-		"publish:prod": "npm run build:packages && lerna publish",
+		"publish:check": "cross-env NODE_ENV=production npm run build:packages && lerna updated",
+		"publish:dev": "cross-env NODE_ENV=production npm run build:packages && lerna publish --npm-tag next",
+		"publish:prod": "cross-env NODE_ENV=production npm run build:packages && lerna publish",
 		"test": "npm run lint && npm run test-unit",
 		"pretest-e2e": "concurrently \"./bin/reset-e2e-tests.sh\" \"npm run build\"",
 		"test-e2e": "wp-scripts test-e2e --config test/e2e/jest.config.json",

webpack.config.js

@@ -60,8 +60,10 @@ gutenbergPackages.forEach( ( name ) => {
 	};
 } );
 
+const isDevelopment = process.env.NODE_ENV === 'development';
+const isPlugin = process.env.NODE_ENV === 'plugin';
 const isProduction = process.env.NODE_ENV === 'production';
-const mode = isProduction ? 'production' : 'development';
+const mode = isProduction || isPlugin ? 'production' : 'development';
 
 const config = {
 	mode,
@@ -167,7 +169,7 @@ const config = {
 		process.env.GUTENBERG_BUNDLE_ANALYZER && new BundleAnalyzerPlugin(),
 		// GUTENBERG_LIVE_RELOAD_PORT global variable changes port on which live reload works
 		// when running watch mode.
-		! isProduction && new LiveReloadPlugin( { port: process.env.GUTENBERG_LIVE_RELOAD_PORT || 35729 } ),
+		isDevelopment && new LiveReloadPlugin( { port: process.env.GUTENBERG_LIVE_RELOAD_PORT || 35729 } ),
 	].filter( Boolean ),
 	stats: {
 		children: false,