Wichita - Tallahassee sidekick

Run your es6 modules in a sandbox with the experimental vm.SourceTextModule.

The following node options are required to run this module

--experimental-vm-modules --no-warnings

If running tests with mocha you have a couple of alternatives:

// .mocharc.js
module.exports = {
  "node-options": ["experimental-vm-modules", "no-warnings"],
}

NODE_OPTIONS="--experimental-vm-modules --no-warnings" mocha -R dot

Api

Wichita takes one required argument:

• sourcePath: required script path, relative from calling file
• options: optional vm context options, passed to vm.createContext
  • moduleRoute: route that will be used when importing modules (optional)
  • fileCache: optional Map, file content cache

and returns an api:

• path: absolute path to file
• caller: absolute path to calling file
• run(sandbox): run es6 module
  • sandbox: required object that will be contextified and used as global context
• exports(sandbox): expose module export functions
  • sandbox: required object
• execute(sandbox, fn): execute function
  • sandbox: required object
  • fn: function that returns module as argument, fn(es6module)

Run script:

const source = new Script("./resources/main");
await source.run({
  setTimeout() {},
  console,
  window: {},
})

Exports:

const source = new Script("./resources/lib/module");
const {default: defaultExport, justReturn} = await source.exports({
  setTimeout() {},
  console,
  window: {},
}

defaultExport(1);
justReturn(2);

Execute:

const source = new Script("./resources/lib/module");
await source.execute({
  setTimeout() {},
  console,
  window: {},
}, (module) => {
  module.default(1);
  module.justReturn(2);
})

Example

"use strict";

const Script = require("@bonniernews/wichita");
const assert = require("assert");

describe("script", () => {
  it("executes scripts in passed context", async () => {
    const source = new Script("./resources/main");

    const context = {
      window: {
        root: true,
      },
    };
    await source.run(context);

    assert.ok(context.window.broker);
    assert.ok(context.window.setByModule);
    assert.equal(context.window.count, 1);
    assert.ok(context.window.setByQueue);
  });

  it("and again", async () => {
    const source = new Script("./resources/main");

    const context = {
      window: {
        root: true,
        count: 2,
      },
    };
    await source.run(context);

    assert.ok(context.window.broker);
    assert.ok(context.window.setByModule);
    assert.equal(context.window.count, 3);
    assert.ok(context.window.setByQueue);
  });

  it("get module exports", async () => {
    const source = new Script("./resources/lib/module");

    const context = {
      window: {
        root: true,
      },
      console,
    };

    const {justReturn} = await source.exports(context);

    assert.equal(justReturn(1), 1);
  });

  it("execute module function", async () => {
    const source = new Script("./resources/lib/module");

    const context = {
      window: {
        root: true,
      },
      console,
    };

    let called;

    await source.execute(context, (module) => {
      called = true;
      assert.equal(module.justReturn(1), 1);
    });

    assert.ok(called);
  });
});

Imports

JSON file import are imported as default:

import data from  "./resources/assets/data.json";

is exported as:

export default { content_of_data_json: true };