Troubleshooting frontend development issues

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Troubleshooting issues

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Testing issues

Property or method `nodeType` is not defined but you’re not using nodeType anywhere

This issue can happen in Vue component tests, when an expectation fails, but there is an error thrown when Jest tries to pretty print the diff in the console. It’s been noted that using toEqual with an array as a property might also be a contributing factor.

See this video for an in-depth overview and investigation.

Remedy - Try cloning the object that has Vue watchers

- expect(wrapper.findComponent(ChildComponent).props()).toEqual(...);
+ expect(cloneDeep(wrapper.findComponent(ChildComponent).props())).toEqual(...)

Remedy - Try using toMatchObject instead of toEqual

- expect(wrapper.findComponent(ChildComponent).props()).toEqual(...);
+ expect(wrapper.findComponent(ChildComponent).props()).toMatchObject(...);

toMatchObject actually changes the nature of the assertion and won’t fail if some items are missing from the expectation.

Script issues

core-js errors when running scripts within the GitLab repository

The following command assumes you’ve set up the GitLab repository in the ~/workspace/gdk directory. When running scripts within the GitLab repository, such as code transformations, you might run into issues with core-js like this:

TypeError: $ is not a function
    at Object.<anonymous> (~/workspace/gdk/gitlab/node_modules/core-js/modules/
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Module._compile (~/workspace/gdk/gitlab/node_modules/pirates/lib/index.js:99:24)
    at Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Object.newLoader [as .js] (~/workspace/gdk/gitlab/node_modules/pirates/lib/index.js:104:7)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (~/workspace/gdk/gitlab/node_modules/core-js/modules/

Remedy - Try moving the script into a separate repository and point to it to files in the GitLab repository

Using Vue component issues

When rendering a component that uses GlFilteredSearch and the component or its parent uses Vue Apollo

When trying to render our component GlFilteredSearch, you might get an error in the component’s provide function:

cannot read suggestionsListClass of undefined

Currently, vue-apollo tries to manually call a component’s provide() in the beforeCreate part of the component lifecycle. This means that when a provide() references props, which aren’t actually setup until after created, it will blow up.

See this closed MR for more context.

Remedy - try providing apolloProvider to the top-level Vue instance options

VueApollo will skip manually running provide() if it sees that an apolloProvider is provided in the $options.

  new Vue(
+   apolloProvider: {},
    render(h) {
      return h(App);