# Description

This PR fixes an issue where the persistence-elastic hook fails on Elasticsearch 8 because the bulk API response is no longer wrapped in a .body property (as it was in Elasticsearch 7). This results in bulkResponse.body being undefined, preventing proper error checks and breaking bulk indexing for ES 8.

This change normalises the bulk response format so it works for both ES 7 and ES 8 by:

• Executing client.bulk({ refresh: true, body })
• Detecting whether the response is wrapped (response.body) or unwrapped (response)
• Using the correct structure in each case
• Preserving backwards compatibility with ES 7
• Adding a unit test to validate ES 8-style behaviour

Fixes #3385

# Checklist

General

• I have clearly described what this PR changes and why.
• I have linked the related issue (Fixes #3385).
• I have added myself to the contributors file.
• All commits include a Signed-off-by line for DCO compliance.

Testing

• I ran the existing test suite for the persistence-elastic hook.
  Command used:
  PATH=$HOME/.bun/bin:$PATH bun test

• I added a unit test for the ES 8 bulk response format.

• Tests pass locally.

Documentation / Misc

• No new files were added, so no SPDX header was required.
• This PR follows GitHub Flow (feature/bugfix branch → PR → review → merge).

# Types of Changes

• Bug Fix — Resolves failure in the persistence-elastic hook when handling ES 8 bulk responses.

# Screenshots / Logs (optional)

N/A — behaviour validated through unit tests.