fix indices.simulate_index_template test spec

[saimedhi]

Description

• fix indices.simulate_index_template test spec

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

✅ Gradle check result for a4a730c: SUCCESS

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.70%. Comparing base (fe4a98d) to head (a4a730c).
Report is 4 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #18399      +/-   ##
============================================
+ Coverage     72.60%   72.70%   +0.09%     
- Complexity    67682    67776      +94     
============================================
  Files          5497     5497              
  Lines        311819   311819              
  Branches      45265    45265              
============================================
+ Hits         226409   226702     +293     
+ Misses        66941    66641     -300     
- Partials      18469    18476       +7     

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[saimedhi]

@owaiskazi19 , @andrross , @dbwiddis please take a look at this PR. And let me know if any change needed.

[andrross]

@saimedhi Can you explain why this change is required?

[saimedhi]

@saimedhi Can you explain why this change is required?

@andrross, I am seeing a test failure in opensearch python client. Same issue observed in other clients as well.
https://github.com/opensearch-project/opensearch-py/actions/runs/15337138495/job/43156422037?pr=907

I debugged this issue and noticed response obtained after sequence of actions mentioned in test spec is {}

So, asserting response body with {} should be done in test spec.

Currently suggesting to change as below:

- match: { $body: {} }

Previously :

- match: {body: null}

[andrross]

@saimedhi But why does this not cause an issue in this repository if the spec is not correct?

[andrross]

@saimedhi I'm going to merge this because I fully believe you that the actual response is {} instead of null :) But can you look into why this didn't cause a failure in the tests here?