Function handler

Gulpfile.ts:507–511

(importee: string)

                // the UMD version when targeting browsers, but we need to use
                // the ESM version so that it can be bundled.
                handler(importee: string) {
                  if (/@jridgewell[\\/].*\.umd\.js$/.test(importee)) {
                    return importee.slice(0, -".umd.js".length) + ".mjs";
                  }
                },
              },
            },
            rollupNodeResolve({