Work around React Native / Metro refusing to load .cjs modules. (#484)

Inspired by apollographql/apollo-client#9716

shared/rollup.config.js

@@ -1,3 +1,5 @@
+import { readFile, writeFile } from "fs/promises";
+
 export const globals = {
  __proto__: null,
  tslib: "tslib",
@@ -22,6 +24,17 @@ export function build(input, output, format) {
  sourcemap: true,
  globals
  },
+ ...(output.endsWith(".cjs") ? { plugins: [
+ { // Inspired by https://github.com/apollographql/apollo-client/pull/9716,
+ // this workaround ensures compatibility with versions of React Native
+ // that refuse to load .cjs modules as CommonJS (to be fixed in v0.72):
+ name: "copy *.cjs to *.cjs.native.js",
+ async writeBundle({ file }) {
+ const buffer = await readFile(file);
+ await writeFile(file + ".native.js", buffer);
+ },
+ },
+ ]} : null),
  };
 }