message: add test for building workers site with custom webpack
diff: @@ -30,6 +30,24 @@ fn it_builds_webpack_site() {
  build_creates_assets(&fixture, vec!["main.js"]);
  }
  +#[test]
  +fn it_builds_webpack_site_with_custom_webpack() {
  + let fixture = Fixture::new_site();
  +
  + fixture.create_file(
  + "workers-site/webpack.worker.js",
  + r#"
  + module.exports = { context: __dirname, entry: "./index.js" };
  + "#,
  + );
  +
  + let mut wrangler_toml = WranglerToml::site("test-build-site-specify-config");
  + wrangler_toml.webpack_config = Some("workers-site/webpack.worker.js");
  + fixture.create_wrangler_toml(wrangler_toml);
  +
  + build_creates_assets(&fixture, vec!["main.js"]);
  +}
  +
  #[test]
  fn it_builds_with_webpack_single_js() {
  let fixture = Fixture::new();
  