feat: implemented span stack trace configuration

[abhilash-sivan]

EPIC link: https://jsw.ibm.com/browse/INSTA-57356

This will be the final PR to main for the stack trace filtering feature!

This PR proposes a refactor of the current instrumentation error/stack logic and introduces a new configuration option (INSTANA_STACK_TRACE) to control stack trace collection behaviour across all instrumentations based on the EPIC design.

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Goals

• Unify and simplify error/stack handling across all instrumentations. -refactor
• Add configurable stack trace modes (none, error, all) - implementation

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1. Refactor & Unify Instrumentation Logic

1.1 Introduce a Common Error / Stack Handling Helper

Unify setError logic

Create a shared helper used by all instrumentations for attaching error details and stack traces.

Ensure getErrorDetails always returns a string

Guarantees consistent type in span.data.<tech>.error.

Implement V8 string → stack trace conversion

Handle cases where the stack arrives as a plain string.
Add a test validating correct conversion behaviour.

Add dedicated tests

At least one test to ensure conversion logic is correct.

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1.2 Update All Instrumentations to Use Shared Logic

All categories will be updated to call the new unified helper:

• DB instrumentations
• Messaging instrumentations
• Protocol / HTTP instrumentations

This ensures:

• Consistent error assignment
• Consistent stack generation / overwrite rules
• Reduced code duplication

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1.3 Add Category-Level Tests

Tests to validate:

• Every category behaves consistently under errors
• Stack traces are attached or removed correctly
• Error fields are stringified

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2. Add Configurable Stack Trace Mode

Introduce a configuration setting:

INSTANA_STACK_TRACE = none | error | all
configuration via agent and custom file

2.1 Implement Stack Trace Mode Behaviour

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2.2 Add or Update Tests

Add full coverage for the three modes:

• none → stack always removed
• error → stack present only on error
• all → stack always present (and overwritten on error)

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Task List Summary

Refactoring Tasks

• Unify setError across all instrumentations
• strong test in generic stack_trace for error case
• Extension of setErrorDetails function: refactor: added error stack replacement logic #2167 (comment)
• setErrorDetails needs to handle err being a string – e.g., nats, natsStreaming
• setErrorDetails needs to handle err.details – e.g., grpcJs
• fix SDK Error capture logic (Different custom key for error)
• Remove usage of getErrorDetails
• Implement V8 string → stack trace conversion
• Add tests for conversion
• Add category-level tests

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Stack Trace Configuration Tasks

• Add INSTANA_STACK_TRACE config
• Add tests for all three modes
• Implement mode logic (none | error | all)

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Optional

• We should not generate stacks at all if span is filtered out

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After Implementation

• Update public documentation to reflect the new configuration and unified behaviour.

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