next-build-webpack-only.js

#!/usr/bin/env node

// @source https://github.com/hashicorp/nextjs-bundle-analysis/issues/13
const { spawn } = require('child_process');

/**
 * Wrap the next build command to only run the webpack step of the build, short-circuiting before static generation.
 */
async function main() {
	const buildProc = spawn('./node_modules/.bin/next', ['build'], {
		env: { ...process.env, FORCE_COLOR: 'true' },
	});

	buildProc.stdout.on('data', (data) => {
		const value = data.toString();
		// This is the log output immediately following the webpack build and before static generation starts,
		// so it should be safe to abort
		if (value.includes('Collecting page data')) {
			console.log('Webpack build finished, exiting.');
			buildProc.kill('SIGINT');
		} else {
			console.log(value.trim());
		}
	});

	buildProc.stderr.on('data', (data) => {
		console.error(data.toString().trim());
	});

	buildProc.on('exit', (code, signal) => {
		if (signal === 'SIGINT') process.exit(0);
		process.exit(code);
	});
}

main();