message: allow fetching each spec
diff: @@ -3,7 +3,7 @@ import * as path from "path";
  import fetch from "node-fetch";
  import { JSDOM } from "jsdom";
  -fetchIDLs();
  +fetchIDLs(process.argv.slice(2));
  interface IDLSource {
  url: string;
  @@ -19,8 +19,9 @@ const idlSelector = [
  const cssPropSelector = "dfn.css[data-dfn-type=property]";
  -async function fetchIDLs() {
  - const idlSources = require("../inputfiles/idlSources.json") as IDLSource[];
  +async function fetchIDLs(filter: string[]) {
  + const idlSources = (require("../inputfiles/idlSources.json") as IDLSource[])
  + .filter(source => !filter.length || filter.includes(source.title));
  await Promise.all(idlSources.map(async source => {
  const { idl, comments } = await fetchIDL(source);
  fs.writeFileSync(path.join(__dirname, `../inputfiles/idl/${source.title}.widl`), idl + '\n');
  