async function bundleCombinedSpecs(options) {
  options = options || {};

  let build = esbuild.build;
  if (options.incremental) {
    build = esbuild.context;
  }

  return build({
    entryPoints: [
      "Specs/spec-main.js",
      "Specs/SpecList.js",
      "Specs/karma-main.js",
    ],
    bundle: true,
    format: "esm",
    sourcemap: true,
    outdir: path.join("Build", "Specs"),
    plugins: [externalResolvePlugin],
    write: options.write,
  });
}
Bundles spec files for testing in the browser and on the command line with karma.
@param {object} options
@param {boolean} [options.incremental=false] true if the build should be cached for repeated rebuilds
@param {boolean} [options.write=false] true if build output should be written to disk. If false, the files that would have been written as in-memory buffers
@returns {Promise<any>}