[2.13]Fix gantt chart UI test failing on empty index-pattern fields

[Qxisylolo]

test result

➜  Opensearch-dashboards-functional-test git:(osd213_gantt_fix) ✗ yarn cypress:run-without-security --browser electron \
  --spec cypress/integration/plugins/gantt-chart-dashboards/gantt_ui.spec.js

yarn run v1.22.19
$ env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=false --browser electron --spec cypress/integration/plugins/gantt-chart-dashboards/gantt_ui.spec.js

====================================================================================================

  (Run Starting)

  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ Cypress:        9.5.4                                                                          │
  │ Browser:        Electron 94 (headless)                                                         │
  │ Node Version:   v22.23.0 (/Users/qianxisy/.local/share/mise/installs/node/22.23.0/bin/node)    │
  │ Specs:          1 found (plugins/gantt-chart-dashboards/gantt_ui.spec.js)                      │
  │ Searched:       cypress/integration/plugins/gantt-chart-dashboards/gantt_ui.spec.js            │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘


────────────────────────────────────────────────────────────────────────────────────────────────────
                                                                                                    
  Running:  plugins/gantt-chart-dashboards/gantt_ui.spec.js                                 (1 of 1)
Browserslist: caniuse-lite is outdated. Please run:
npx browserslist@latest --update-db

Why you should do it regularly:
https://github.com/browserslist/browserslist#browsers-data-updating


  Dump test data
    ✓ Indexes test data for gantt chart

  Save a gantt chart
    ✓ Creates and saves a gantt chart (17572ms)

  Render and configure a gantt chart
    ✓ Renders no data message (11855ms)
    ✓ Renders the chart (12281ms)

  Configure panel settings
    ✓ Changes y-axis label (11149ms)
    ✓ Changes x-axis label (11911ms)
    ✓ Changes time formats (12429ms)
    ✓ Hides legends (11529ms)

  Add gantt chart to dashboard
    ✓ Adds gantt chart to dashboard


  9 passing (2m)


  (Results)

  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ Tests:        9                                                                                │
  │ Passing:      9                                                                                │
  │ Failing:      0                                                                                │
  │ Pending:      0                                                                                │
  │ Skipped:      0                                                                                │
  │ Screenshots:  0                                                                                │
  │ Video:        true                                                                             │
  │ Duration:     1 minute, 35 seconds                                                             │
  │ Spec Ran:     plugins/gantt-chart-dashboards/gantt_ui.spec.js                                  │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘


  (Video)

  -  Started processing:  Compressing to 32 CRF                                                     
  -  Finished processing: /Users/qianxisy/co404/testss/Opensearch-dashboards-function    (5 seconds)
                          al-test/cypress/videos/plugins/gantt-chart-dashboards/gantt               
                          _ui.spec.js.mp4                                                           


====================================================================================================

  (Run Finished)


       Spec                                              Tests  Passing  Failing  Pending  Skipped  
  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ ✔  plugins/gantt-chart-dashboards/gant      01:35        9        9        -        -        - │
  │    t_ui.spec.js                                                                                │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘
    ✔  All specs passed!                        01:35        9        9        -        -        -  

✨  Done in 115.15s.

Issues Resolved

[List any issues this PR will resolve]

Check List

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[github-actions]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🧪 No relevant tests

🔒 No security concerns identified

✅ No TODO sections

🔀 No multiple PR themes

⚡ No major issues detected

[github-actions]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Guard against missing fields in response Guard against a missing or empty fields array in the _fields_for_wildcard response to avoid JSON.stringify(undefined) producing an invalid fields attribute, which would recreate the bug this PR is trying to fix. Fallback to an empty array (or fail early) when the fields list is not present. cypress/integration/plugins/gantt-chart-dashboards/gantt_ui.spec.js [55-68] }).then((resp) => { + const fields = (resp.body && resp.body.fields) || []; cy.request({ method: 'POST', failOnStatusCode: false, url: `api/saved_objects/index-pattern/${INDEX}`, headers: { 'content-type': 'application/json', 'osd-xsrf': true }, body: JSON.stringify({ attributes: { title: INDEX, - fields: JSON.stringify(resp.body.fields), + fields: JSON.stringify(fields), }, }), }); }); Suggestion importance[1-10]: 5 __ Why: Adding a fallback for missing fields in the response is a reasonable defensive measure in a test that specifically aims to fix an index-pattern fields issue, though in practice the endpoint should always return fields.	Low
General	Prefer retry-ability over fixed waits Add a blank line between the delay constant declaration and the describe block for readability, and consider using Cypress's built-in retry-ability (e.g., .should()) instead of arbitrary cy.wait(delay) calls, which are flaky. cypress/integration/plugins/gantt-chart-dashboards/gantt_ui.spec.js [21-23] const INDEX = 'jaeger'; const delay = 100; + describe('Dump test data', () => { Suggestion importance[1-10]: 4 __ Why: The suggestion combines a minor formatting nit with a valid general recommendation to avoid fixed cy.wait() calls for flakiness, but it's not actionable as a concrete code change and only marginally improves the PR.	Low

[wanglam]

LGTM. Same correct fix as the other branch backports — dynamically discovers fields from indexed data rather than hardcoding. Solid approach.