[Discover] Fix ES|QL extra fetches

[davismcphee]

Summary

WIP.

Checklist

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• This was checked for breaking HTTP API changes, and any breaking changes have been approved by the breaking-change committee. The release_note:breaking label should be applied in these situations.
• Flaky Test Runner was used on any tests changed
• The PR description includes the appropriate Release Notes section, and the correct release_note:* label is applied per the guidelines
• Review the backport guidelines and apply applicable backport:* labels.

[elasticmachine]

🤖 Jobs for this PR can be triggered through checkboxes. 🚧

ℹ️ To trigger the CI, please tick the checkbox below 👇

• Click to trigger kibana-pull-request for this PR!
• Click to trigger kibana-deploy-project-from-pr for this PR!
• Click to trigger kibana-deploy-cloud-from-pr for this PR!

[kibanamachine]

Flaky Test Runner Stats

🟠 Some tests failed. - kibana-flaky-test-suite-runner#9452

[❌] src/platform/test/functional/apps/discover/group3/config.ts: 5/50 tests passed.

see run history

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: f697959

Failed CI Steps

• FTR Configs #58
• FTR Configs #58
• Scout: [ observability / observability_onboarding ] plugin

Test Failures

• [job] [logs] FTR Configs #58 / discover/group3 discover request counts ES|QL mode should send 2 requests (documents + chart) when refreshing
• [job] [logs] FTR Configs #58 / discover/group3 discover request counts ES|QL mode should send 2 requests (documents + chart) when refreshing

Metrics [docs]

✅ unchanged

History

cc @davismcphee

[kertal]

FYI @davismcphee attempting to solve the extra fetching request count and because we chatted about this
@drewdaemon mentioned yesterday, that this might be easier with Scout
High likely we should not migrate now, but good to know
#236481

[davismcphee]

@kertal Oh that sounds promising. Especially considering any approach I've found for FTR is pretty hacky. @drewdaemon Could you share more info on how we could track in flight requests with Scout?

[drewdaemon]

@davismcphee I think you can do it via a CDPSession object which lets you use the Chrome Devtools Protocol directly

test('request count', async ({ page, context }) => {
  const cdp = await context.newCDPSession(page);
  await cdp.send('Network.enable');
  cdp.on('Network.requestWillBeSent', (event) => { // doc: https://chromedevtools.github.io/devtools-protocol/tot/Network/#event-requestWillBeSent
    if (/* check event.request.url */) {
      // count requests
    }
  });

  // load page and wait for something relevant

  // assert
});

kudos to @dmlemeshko who pointed this out to me