const fs = require('fs'); const process = require('process'); const assert = require('assert'); const buffer = fs.readFileSync(process.argv[2]); let m = new WebAssembly.Module(buffer); sections = WebAssembly.Module.customSections(m, "foo"); console.log('section foo', sections); assert.strictEqual(sections.length, 1, "didn't create `foo` section"); section = new Uint8Array(sections[0]); console.log('contents', section); assert.strictEqual(section.length, 4, "didn't concatenate `foo` sections"); process.exit(0);