Closes #6879 Add meta generator

[remyperona]

Description

Fixes #6879

Add meta tag generator to HTML when optimized

Type of change

• Enhancement (non-breaking change which improves an existing functionality).

Detailed scenario

In optimized HTML, a new meta tag is added:
<meta name="generator" content="WP Rocket" data-wpr-features="" />

The data-wpr-features contains the list of features enabled.

Using rocket_disable_meta_generator filter set to true prevents the meta tag from being added.

Using rocket_display_meta_generator_content set to false removes the content="WP Rocket" part.

Technical description

Documentation

Explain how this code works. Diagrams & drawings are welcome.

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria. If possible, provide screenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I implemented built-in tests to cover the new/changed code.

Code style

• I wrote a self-explanatory code about what it does.
• I protected entry points against unexpected inputs.
• I did not introduce unnecessary complexity.

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
Report missing for 3c774bb1	✅ 76.24% (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (3c774bb)	Report Missing	Report Missing	Report Missing
Head commit (a923ddd)	37818	16660	44.05%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#7034)	101	77	76.24%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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_{Codacy stopped sending the deprecated coverage status on June 5th, 2024. Learn more}

Footnotes

1. Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct. ↩

[jeawhanlee]

Also I noticed that manual_preload was not added to the meta or not?

[remyperona]

the preload value is not on the list of things we need to log in the meta

[Mai-Saad]

@Tabrisrp Thanks for the PR. Please find the exploratory test notes below:

• Preload fonts are not added in meta now, can you please check? sample page https://new.rocketlabsqa.ovh/combine-v1-v2-fonts/
• If CDN is enabled + no DNS prefetch in the source, we still add DNS prefetch to meta tag. sample page https://new.rocketlabsqa.ovh/lrc_6959_simple/ ==> We shouldn't add DNS-prefetch to the meta tag in this case
• meta tag added to login pages while cache for loggedin is enabled => we shouldn't add it in this case

[piotrbak]

Updated the Acceptance Criteria based on @Mai-Saad findings:

1. wpr_cached will be part of the future enhancement
2. wpr_cached_desktop and wpr_cached_mobile should become wpr_desktop and wpr_mobile. They should be added even if the page is optimised (even if not cached). Notion
3. When CDN is enabled + nothing added to the DNS Prefetch section, we should not add the wpr_dns_prefetch
4. When CDN is enabled + something is added to the DNS Prefetch section, we should add the wpr_dns_prefetch
5. Meta tag should not be added when serving the User Cache
6. For the asynchronous features, there's additional request here. The meta tag should be added when applying the optimization.

Bugfixes:

1. Preload fonts not working based on this comment

@remyperona I included everything in this comment, Mai's findings above.
CC @Mai-Saad

[remyperona]

When CDN is enabled, the CDN URL is automatically added to the DNS prefetch values using the filter, so that's expected that wpr_dns_prefetch is added in that case.

[piotrbak]

@remyperona Couldn't we do a check there, for example:

1. If CDN is enabled
2. There's only one value in DNS Prefetch
3. Don't add the meta tag

[remyperona]

We can, I was explaining why it was happening that way.

Preload fonts are not added in meta now, can you please check? sample page https://new.rocketlabsqa.ovh/combine-v1-v2-fonts/

I can't see any preloaded font on this link. When testing locally with a font added in the preload fonts field, it works correctly. What is the configuration tested on that page?

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
Report missing for 3c774bb1	✅ 77.57% (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (3c774bb)	Report Missing	Report Missing	Report Missing
Head commit (83cff8f)	37826	16667	44.06%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#7034)	107	83	77.57%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences

_{Codacy stopped sending the deprecated coverage status on June 5th, 2024. Learn more}

Footnotes

1. Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct. ↩

[remyperona]

PR is updated, all points taken care of, waiting for feedback related to the preload fonts.

[Mai-Saad]

Working as expected, failed test have separate GH (already on trunk)
testrail-report-651.pdf