更新Jest测试库后的意外令牌(SyntaxError)

Question

在使用Jest运行测试套件时，我遇到了警告，这些警告要求我更新包：

npm WARN deprecated jest-dom@2.1.1:  jest-dom has moved to @testing-library/jest-dom. Please uninstall jest-dom and install @testing-library/jest-dom instead, or use an older version of jest-dom. Learn more about this change here: https://github.com/testing-library/dom-testing-library/issues/260 Thanks! :)
npm WARN deprecated react-testing-library@5.9.0:   react-testing-library has moved to @testing-library/react. Please uninstall react-testing-library and install @testing-library/react instead, or use an older version of react-testing-library. Learn more about this change here: https://github.com/testing-library/dom-testing-library/issues/260 Thanks! :)

在package.json中，我更改了以下内容

"jest-dom": "^2.1.1",
"react-testing-library": "^5.3.0"

至

"@testing-library/jest-dom": "^5.11.1",
"@testing-library/react": "^10.4.7"

当然，从

import "jest-dom/extend-expect";

至

import "@testing-library/jest-dom";

等。

在删除旧的和添加新的后，我得到了多个错误，使我的测试失败(只在我的信号量CI设置，而不是在我的本地机器上)。

FAIL src/redux/actions/tests/myActions.test.js
  ● Test suite failed to run
    Jest encountered an unexpected token
    This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
    By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
    Here's what you can do:
     • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
     • If you need a custom transformation specify a "transform" option in your config.
     • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
    You'll find more details and examples of these config options in the docs:
    https://jestjs.io/docs/en/configuration.html
    Details:
    /home/semaphore/my-app/client/node_modules/@testing-library/dom/dist/helpers.js:44
        } catch {// not using Jest's modern fake timers
                ^
    SyntaxError: Unexpected token {
      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:403:17)
      at Object.<anonymous> (node_modules/@testing-library/dom/dist/pretty-dom.js:13:16)
      at Object.<anonymous> (node_modules/@testing-library/dom/dist/config.js:11:18)

我不是一个前端开发人员，所以我很高兴听到更多的信息需要帮助。非常感谢!

Answer 1

该错误指的是optional catch binding，它是现代JS特性，支持自Node 10。这意味着@testing-library/dom包不支持较旧的Node版本，这可以通过在其package.json中检查engines部分来确认。

一个更好的解决方案是更新Node.js，因为8已经到了生命的尽头。或者，可以将包降级为较低的主要版本，或者将其转到transformIgnorePatterns中的白色列表中，就像错误提示的那样。

Answer 2

@Estus的回答是完全正确的，我投了赞成票。只是想添加实际的修复，如果你也使用信号量作为你的CI，所以你不需要花更多的时间调查，像我一样。

确保您的当前节点版本至少是最新的稳定的LTS，并且您在本地使用的版本是您的测试通过的版本，如果您还没有semaphore.yml.的

• ，则生成一个.nvmrc文件：确定您在中调用nvm use每个块

也就是说，使用外推法对你的项目，版本这个：https://github.com/semaphoreci-demos/semaphore-demo-javascript/blob/master/.semaphore/semaphore.yml。

这将确保节点版本是同步的，并且应该解决在CI中遇到的任何"SyntaxError:意外令牌{“错误，只要相同的测试在本地通过。如果不指定节点版本，则信号量使用v8.17.0作为默认(https://docs.semaphoreci.com/ci-cd-environment/ubuntu-18.04-image/#javascript-via-node-js)！因此，为什么没有指定版本的人在升级任何Jest时都会遇到这个错误。