[improve][fn] Introduce NewOutputMessageWithError to enable error handling

[beelis]

Fixes #24121

Motivation

When an error occurs during the sending of a message using NewOutputMessage, the go function exits with a panic. This behavior prevents the application from handling the error gracefully, as it bypasses any error-handling logic.

Errors should be returned by the new introduced func NewOutputMessageWithError so they can be handled by the calling code, rather than causing a panic.

Modifications

Return the error on NewOutputMessageWithError

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: https://github.com/beelis/pulsar/tree/enhancements/24121/Return-error-on-NewOutputMessage

[nodece]

This PR breaks the public API.

Could you consider that add the NewOutputMessageWithError to the FunctionContext?

[beelis]

Hi @nodece
Thank you for your review and feedback, i introduced the new func NewOutputMessageWithError.
Cheers, Simon

[nodece]

Please check.

[Copilot]

Pull Request Overview

This pull request introduces a new error-handling function, NewOutputMessageWithError, to allow graceful error handling when sending output messages in the Go Pulsar function implementation.

• Add a new function in both instance.go and context.go to return an error instead of panicking.
• Update tests in context_test.go to cover the new function.
• Minor refactoring in util_test.go to improve variable naming.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
pulsar-function-go/pf/util_test.go	Corrected a typo in variable naming from actualtMap to actualMap.
pulsar-function-go/pf/instance.go	Introduced a new outputMessageWithError function to support error handling.
pulsar-function-go/pf/context_test.go	Added test cases for the new NewOutputMessageWithError functionality.
pulsar-function-go/pf/context.go	Added a new field and method for NewOutputMessageWithError.

Comments suppressed due to low confidence (2)

pulsar-function-go/pf/instance.go:83

• [nitpick] Consider adding a space after 'error is:' in the error message for improved readability, for example: "getting producer failed, error is: %v".

log.Errorf("getting producer failed, error is:%v", err)

pulsar-function-go/pf/context_test.go:126

• Comparing errors by value can lead to false negatives since two errors with the same message may not be equal if they are distinct instances. Consider using assert.EqualError(t, err, "test error") or comparing error messages.

assert.Equal(t, testCase.expectedError, err)

[lhotari]

LGTM, good work @beelis

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.24%. Comparing base (bbc6224) to head (c288ae0).
Report is 999 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #24122      +/-   ##
============================================
+ Coverage     73.57%   74.24%   +0.66%     
+ Complexity    32624    32484     -140     
============================================
  Files          1877     1864      -13     
  Lines        139502   144453    +4951     
  Branches      15299    16479    +1180     
============================================
+ Hits         102638   107244    +4606     
+ Misses        28908    28747     -161     
- Partials       7956     8462     +506     

Flag	Coverage Δ
inttests	26.68% <ø> (+2.10%)	⬆️
systests	23.19% <ø> (-1.14%)	⬇️
unittests	73.74% <ø> (+0.89%)	⬆️

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see 1068 files with indirect coverage changes

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