升级 Cucumber 2.4 -> 4.0 失败:无法加载此类文件 -- cucumber/core/gherkin/tag_expression (LoadError)

Upgrade Cucumber 2.4 -> 4.0 failed: cannot load such file -- cucumber/core/gherkin/tag_expression (LoadError)

将 Cucumber 框架从 2.4 升级到 4.0,运行 成为一个问题:

Start Test Suite [ 2019-02-14 13:15:40 -0800 ]
Selenium standalone isn't running. Starting standalone server in background.
Determining host operating system... darwin18.2.0
Determining host operating system... darwin18.2.0
cannot load such file -- cucumber/core/gherkin/tag_expression (LoadError)
SITE_TYPE: desktop  DEBUG_MODE: false  SELENIUM_ENV: local  SELENIUM BROWSER: firefox  RERUN_TEST: false
quitting browser
End Test Suite [ 2019-02-14 13:15:42 -0800 ] 

无论有没有标签都无法启动任何测试,如果有人可以分享一些关于如何调试它的想法,我们将不胜感激?

tag_expression 被移动到另一个 gem:称为 cucumber-tag_expressions, as mentioned here。根据代码中出现此错误的位置,您可能需要更改引发错误的 require,或者您可能只需要安装 gem.

我注意到的另一件事是 Cucumber 4.0 仍在 RC(候选发布版)中,尚未稳定,因此您可能想恢复到最新的稳定版本,即今天的 3.1.2,可能会解决这个问题。