SLT.BETA.013 – Improve split helper implementation

[flyingrobots]

[SLT.BETA.013] Improve split helper implementation

Overview

Refactor Bosun's split_string helper to use local arrays/readarray for performance and document delimiter semantics, especially for multi-character separators.

References & Assets

• Figma / Design: N/A
• Product Spec: N/A
• Related Issues / PRs: Bosun helper improvements
• Feature Flags / Experiments: N/A
• Other Assets: scripts/bosun

User Story

As a Bosun contributor, I want a reliable split helper with documented behavior so that table rendering and CLI parsing remain fast and predictable.

Acceptance Criteria

• split_string refactored to use local arrays/readarray for performance
• Documentation clarifies multi-character delimiter behavior
• Tests cover edge cases (empty fields, multi-character separators, trailing delimiters)

Definition of Done

Updated helper implementation, documentation, and tests merged, with lint/tests passing.

Scope

In-Scope

• Refactor of split helper
• Documentation updates
• Test coverage for edge cases

Out-of-Scope

• Broader Bosun refactors beyond split helper

Deliverables

• Est. Lines of Code: ~120
• Est. Blast Radius: scripts/bosun, docs/bosun.md, tests

Implementation Details

High-Level Approach

Replace manual parsing with readarray/IFS aware approach, ensure helper remains POSIX-compatible, and update docstring and README examples.

Affected Areas

• scripts/bosun
• docs/bosun.md
• tests/bosun_split.bats

Implementation Steps

• Refactor helper using local arrays
• Document delimiter semantics in docs/bosun.md
• Add tests for edge cases

Test Plan

Happy Path

• Splitting typical output returns expected fields

Edge Cases

• Multi-character and trailing delimiters handled correctly
• Empty input returns empty array without errors

Failure Cases

• Invalid delimiter surfaces helpful error (if applicable)

Monitoring & Success Metrics

• No regressions in Bosun CLI tests

QA Sign-off Matrix

Environment	Surface	Owner	Status	Notes
Local Docker	Bosun CLI	TBD	Pending	Validate via make test

Requirements

Hard Requirements

• Helper must remain shell-compatible and efficient

Soft Requirements

• Document usage for contributors

Runtime Requirements

• Works on all supported distros in Docker matrix

Dependencies & Approvals

• None

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Production Notes

Priority: 3 / 5

Performance/maintainability improvement (P2).

Complexity: 2 / 5

Focused helper refactor.

Estimate: 6 - 8 hours

Includes implementation, docs, tests.

Risk & Rollback

• Primary Risks: Regression in CLI parsing
• Mitigations: Tests for edge cases
• Rollback / Kill Switch: Revert helper change

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Additional Notes

Ensure helper remains backward compatible with existing callers.

[flyingrobots]

Estimate: 3 hours.

Rationale:

• Refactor split_string to use local arrays
• Document delimiter semantics
• Add tests for edge cases