Intern-cucumber插件错误：名为“ cucumber”的插件尚未注册

Question

我正在尝试使内部黄瓜插件正常工作。我收到以下错误：

Error: A plugin named "cucumber" has not been registered
  at Node.BaseExecutor.getPlugin @ srclibexecutorsExecutor.ts:387:12
  @ testsaddition.js:6:29
  at runFactory @ node_modulesdojodojo.js:1134:43
  at execModule @ node_modulesdojodojo.js:1262:5
  at execModule @ node_modulesdojodojo.js:1253:12
  @ node_modulesdojodojo.js:1297:6
  at guardCheckComplete @ node_modulesdojodojo.js:1277:5
  at checkComplete @ node_modulesdojodojo.js:1292:4
  at contextRequire @ node_modulesdojodojo.js:835:6
  at req @ node_modulesdojodojo.js:124:11
  @ srcloadersdojo.ts:36:8
  at new Promise @ anonymous
  at Node._loader @ srcloadersdojo.ts:29:13
  at Node._loadFunctionalSuites @ srclibexecutorsNode.ts:593:29
  @ srclibexecutorsNode.ts:882:24
  @ node_modules@theinterncommonindex.js:16:7174

关于如何解决此问题的任何想法？我的intern.json配置文件如下所示：

{
  "loader": {
    "script": "dojo",
    "options": {
      "packages": [
        {
          "name": "features",
          "location": "features"
        },
        {
          "name": "models",
          "location": "models"
        },
        {
          "name": "dojo", 
          "location":  "node_modules/dojo"
        }
      ]
    }
  },
  "functionalSuites": "tests/**.js",
  "environments": [ "chrome" ],
  "browser": {
    "plugins": [
      "node_modules/intern-cucumber/browser/plugin.js"
    ]
  },
  "node": {
    "plugins": "node_modules/intern-cucumber/plugin.js"
  }

}

和我的测试文件，发生错误的地方，additional.js看起来像：

define([
    'models/calculator',
    'dojo/text!features/addition.feature'
], function (calculator, featureSrc) {

    const cucumber = intern.getPlugin('cucumber');
    const assert = intern.getPlugin('chai').assert; 

    cucumber.registerCucumber('Calculator addition', featureSrc, function () {

        cucumber.Given('the calculator is cleared', function () {

        });

        cucumber.When(/^I add (d+) and (d+)$/, function (x, y) {
            var calc = new Calculator(x, y)

        })

        cucumber.Then(/^the result should be (d+)$/, function (z) {
            var result = calc.sum();
            assert.equal(z,result,'Expected result to be: ' + z)
        })
    }

    )
}

)

有人知道如何解决这个问题吗？不知道为什么插件不起作用，我的intern.json文件有问题吗？