Add "comments" in the JSON of expected results to track "weird" expectations and avoid confusion and questions

[MathieuLamiot]

Context https://wp-media.slack.com/archives/C05NH7JU4S2/p1719573044181989

Expected behavior

• Define a way to add "comments" in the JSON for expected results of LCP/ATF. JSON file don't take comments but we could add a field dedicated for this, and make sure it does not break the code.
• Add comments for desktop and mobile for the following templates, based on the Slack discussion:
  • lcp_single_double
  • lcp_6647_svgbg_template

[MathieuLamiot]

From @Khadreal:

Hello, Following this https://wp-media.slack.com/archives/C05NH7JU4S2/p1719573044181989 for https://github.com/wp-media/wp-rocket-e2e/issues/121 but not quite sure what the comments should be like

So, on this issue, there are two things to do:

1. Define a way to add "comments" to the templates in the JSON file, as JSON files don't natively support comments.
2. Write the comments for the two templates that are confusing.

For instance here, we could do:

  "lcp_6647_svgbg_template": {
    "comment": "Contains only SVG and background-image styles starting with data:image. Those are not captured by our OCI feature.",
    "lcp": [],
    "viewport": [],
    "enabled": true
  },

About this one Maybe:

  "lcp_single_double": {
    "comment": "LCP on this template is from an <input> tag which is not handled by default. Hence, we expect no LCP to be identified.",
    "lcp": [
    ],
    "viewport": [],
    "enabled": true
  },

Note that those added comments should be duplicated for both mobile and desktop json files.

What is really needed in this issue? From a development perspective, it's quite shallow. What is needed here is mostly:

• Ensuring that adding those comment fields does not break anything (and if it does, find another approach)
• Share the fact that we can add comments this way with the QA team so that they can do it themselves if needed in the future to ease maintenance of the lists.