How can I specify --experimental-specifier-resolution flag to be included in supertest or chai-http node server?

Question

I'm building node express app and recently I wanted to write some tests with mocha. I'm willing to use chai-htpp plugin to run my app during tests. The problem is, I'm using --experimental-specifier-resolution flag on application launch to enable directory/barrel imports(I'm using ES modules format which somehow does not tolerate such thing for now). Example below.

import chai from "chai";
import chaiHttp from "chai-http";
import app from "../src/index.js";

chai.use(chaiHttp);


describe("Test one", () => {
  describe("should be happy", () => {
    it("something", (done) => {
      chai
      .request(app)
      .get("/")
        .end((err, res) => {
          console.log("ERR", err);
          console.log("RES", res);
          done();
        });
      });
    });
  });

running this test with mocha throws following error

Error [ERR_UNSUPPORTED_DIR_IMPORT]: Directory import '/home/konrad/Projects/MW/src/routes' is not supported resolving ES modules imported from /home/konrad/Projects/MW/src/index.js
    at new NodeError (node:internal/errors:372:5)
    at finalizeResolution (node:internal/modules/esm/resolve:433:17)
    at moduleResolve (node:internal/modules/esm/resolve:1009:10)
    at defaultResolve (node:internal/modules/esm/resolve:1218:11)
    at ESMLoader.resolve (node:internal/modules/esm/loader:580:30)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:294:18)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:80:40)
    at link (node:internal/modules/esm/module_job:78:36)

Is there a way to customize chai/supertest server launch and pass --experimental-specifier-resolution flag? Or maybe there is more elegant way you can think of.

Answer 1

Set node-option to pass a node or v8 argument.

mocha --node-option experimental-specifier-resolution=explicit tests

or via mocha opts

  "mocha": {
    "node-option": [
      "experimental-specifier-resolution=explicit"
    ]
  }