Make Jest work with gitlab-ui
Currently when you are testing a component in Jest that uses gitlab-ui, you get an error similar to this:
FAIL spec/frontend/notes/components/discussion_jump_to_next_button_spec.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:
/Users/winnie/Projects/gdk-ce/gitlab/node_modules/@gitlab/ui/dist/index.js:112896
export { Chart$1 as GlChart, area as GlAreaChart, ChartTooltip as GlChartTooltip, link as GlLink, GlLoadingIcon, modal as GlModal, pagination as GlPagination, Popover as GlPopover, progress_bar as GlProgressBar, skeleton_loading as GlSkeletonLoading, GlButton, tooltip$1 as GlTooltip, empty_state as GlEmptyState, GlFormInput, search_box as GlSearchBox, dropdown_item as GlDropdownItem, dropdown_header as GlDropdownHeader, dropdown_divider as GlDropdownDivider, dropdown as GlDropdown, table as GlTable, Modal as GlModalDirective, Tooltip as GlTooltipDirective };
^^^^^^
SyntaxError: Unexpected token export
1 | <script>
2 | import icon from '~/vue_shared/components/icon.vue';
> 3 | import { GlTooltipDirective } from '@gitlab/ui';
| ^
4 |
5 | export default {
6 | name: 'JumpToNextDiscussionButton',
at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:403:17)
at app/assets/javascripts/notes/components/discussion_jump_to_next_button.vue:3:1
at Object.<anonymous> (app/assets/javascripts/notes/components/discussion_jump_to_next_button.vue:31:3)
It is probably sufficient to add this to our Jest config:
"transformIgnorePatterns": [
"node_modules/(?!(@gitlab/ui)/)"
]