Build each entry independently when testing Vite

[romaricpascal]

Builds initAll.mjs and single-component.mjs independently during Vite integration tests, to work around Vite cleverly optimising a build with multiple entries by splitting shared code in a separate file. After investigation, it seems we can only make separate builds to circumvent that cleverness.

Simplest option looked to allow to pass the name of the file through environment variable, so we can run the build command multiple times targeting a separate entry. As we want to have the same build folder structure as for Webpack and Rollup, both builds will need to output to the same folder, for which we need to disable Vite automatically cleaning up its build folder.

Closes #4978.

[github-actions]

📋 Stats

File sizes

File	Size
dist/govuk-frontend-development.min.css	113.32 KiB
dist/govuk-frontend-development.min.js	42.34 KiB
packages/govuk-frontend/dist/govuk/all.bundle.js	88.16 KiB
packages/govuk-frontend/dist/govuk/all.bundle.mjs	82.83 KiB
packages/govuk-frontend/dist/govuk/all.mjs	981 B
packages/govuk-frontend/dist/govuk/govuk-frontend-component.mjs	359 B
packages/govuk-frontend/dist/govuk/govuk-frontend.min.css	113.3 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend.min.js	42.33 KiB
packages/govuk-frontend/dist/govuk/i18n.mjs	5.55 KiB
packages/govuk-frontend/dist/govuk/init.mjs	4.86 KiB

Modules

File	Size (bundled)	Size (minified)
all.mjs	78.45 KiB	40.31 KiB
accordion.mjs	22.71 KiB	12.85 KiB
button.mjs	5.98 KiB	2.69 KiB
character-count.mjs	22.4 KiB	9.92 KiB
checkboxes.mjs	5.83 KiB	2.83 KiB
error-summary.mjs	7.89 KiB	3.46 KiB
exit-this-page.mjs	17.1 KiB	9.26 KiB
header.mjs	4.46 KiB	2.6 KiB
notification-banner.mjs	6.26 KiB	2.62 KiB
password-input.mjs	15.15 KiB	7.25 KiB
radios.mjs	4.83 KiB	2.38 KiB
skip-link.mjs	4.39 KiB	2.18 KiB
tabs.mjs	10.13 KiB	6.11 KiB

View stats and visualisations on the review app

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Action run for a6628e8

[romaricpascal]

note Set a default here to avoid things breaking badly when runing Vite outside of npm run vite -w @govuk-frontend/bundler-integrations

[36degrees]

Makes sense to me 👍🏻