Feature to ignore specific ResourceTypes in Puppeteer

[samvloeberghs]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/scullyio/scully/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Other... Please describe:

What is the current behavior?

All images / fonts / stylesheets are currently also loaded in Puppeteer when requesting a page. In most cases they are not relevant for prerendering the HTML.

What is the new behavior?

Any ResourceType that is listed here will be ignored by the Puppeteer instance rendering the requested page. For example if you add image and fonts all requests to images and fonts loaded on your pages will be blocked.

Does this PR introduce a breaking change?

• Yes
• No (it's opt-in)

Other information

[samvloeberghs]

Can we first validate the change? If all good I will add tests where applicable!

[samvloeberghs]

Can we first validate the change? If all good I will add tests where applicable!

Can't seem to find any case where I should update / add tests. Is that correct?

[SanderElias]

@samvloeberghs the tests are in the /test folder. We have jest and cypress e2e tests in there.
They there Scully as a whole, not the individual parts.

[samvloeberghs]

@SanderElias
I have ran the tests like this and did not experience issues:

1. Did a first check of the configuration / process.
   Running Scully with the sampleBlog.config generated output in dist/static/.
   Running the tests with jest yielded no errors

npm i
npx nx build scully --prod
npx nx build ng-lib --prod
npx nx build scully-plugin-flash-prevention --prod
npm run symlinks
npx nx build sample-blog --prod
node ./dist/libs/scully/scully --configFile scully.sampleBlog.config.js --tds
npm run jest:test

2. Updated the scully.sampleBlog.config.js to include the to ignore ResourceTypes:

  ignoreResourceTypes: [
    'image',
    'stylesheet',
    'media',
    'font'
  ]

3. Redid the testing process, no errors, so the output is the same!

node ./dist/libs/scully/scully --configFile scully.sampleBlog.config.js --tds
npm run jest:test

[aaronfrost]

@samvloeberghs after the testing... any chance that you noticed an improvement in speed? If so, can you comment?

[samvloeberghs]

In the order of 100 pages there was no performance improvement. I would need to run the tests for 1000 and 10000 pages.

But the amount of bandwidth potentially saved is enormous in those test cases.