问使用Jest测试包含未定义函数的代码

EN

// run any data migrations
on("sheet:opened", () => {
    sheetMigration();

    getAttrs(["btatow_sheet_version"], ({
        btatow_sheet_version
    }) => {
        if (btatow_sheet_version >= 3) {
            recalculateSkills();
        }
    });
});

...

// calculate stat values when XP amount changes
on("change:strength_xp change:body_xp change:reflex_xp change:dexterity_xp change:intelligence_xp change:will_xp change:charisma_xp change:edge_xp", calculateAbilityScore)

const calculateLinkedAttributeValue = attribute => {
    if (attribute > 10) {
        return Math.floor(attribute / 3);
    } else {
        if (attribute < 1)
            return -4;
        else if (attribute < 2)
            return -2;
        else if (attribute < 4)
            return -1;
        else if (attribute < 7)
            return 0;
        else if (attribute < 10)
            return 1;
        else
            return 2;
    }
}

...

// exports for testing
module.exports = calculateLinkedAttributeValue

const calculateLinkedAttributeValue = require('./sheet-worker')

test('should calculate linked attribute value for attribute value of 0', () => {
    expect(calculateLinkedAttributeValue(0)).toBe(-4)
})

{
  "name": "battletech-a-time-of-war",
  "version": "1.0.0",
  "description": "Character sheet for Roll20 for the A Time of War TTRPG system.",
  "main": "index.js",
  "scripts": {
    "test": "jest"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "jest": "^26.0.1"
  },
  "type": "module",
  "sourceType": "module"
}

C:\Stuff\Development\roll20-character-sheets\BattleTech-A-Time-of-War\development>npm run test

> battletech-a-time-of-war@1.0.0 test C:\Stuff\Development\roll20-character-sheets\BattleTech-A-Time-of-War
> jest

 FAIL  development/sheet-worker.test.js
  ● Test suite failed to run

    ReferenceError: on is not defined

      1 | // run any data migrations
    > 2 | on("sheet:opened", () => {
        | ^
      3 |     sheetMigration();
      4 |
      5 |     getAttrs(["btatow_sheet_version"], ({

      at Object.<anonymous> (development/sheet-worker.js:2:1)
      at Object.<anonymous> (development/sheet-worker.test.js:1:39)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        1.226 s
Ran all test suites.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! battletech-a-time-of-war@1.0.0 test: `jest`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the battletech-a-time-of-war@1.0.0 test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\<User>\AppData\Roaming\npm-cache\_logs\2020-06-01T09_59_15_484Z-debug.log