webext-buildtools-dir-reader-mw - npm

const DirReaderBuilder = require('webext-buildtools-dir-reader-mw').default;

const options = { zipOutPath: './out/ext.zip' };
const logMethod = console.log;
const builder = new DirReaderBuilder(options, logMethod);

builder.setInputDirPath('./ext_dir');

builder.requireZipFile();
builder.requireManifest();

const buildResult = await builder.build();