What

Restructures lib/helpers/composeSignals.js from a nested if-block to an early-return pattern, reducing indentation and making the flow clearer.

Changes

• Flips the outer if (timeout || length) to if (!timeout && !signals.length) return;
• Uses const for the AbortController (not reassigned)
• Explicitly initializes aborted = false instead of relying on implicit undefined
• Adds a guard clause if (!signals) return at the top of unsubscribe for cleaner double-call protection
• Preserves the existing manual event-listener approach

Why not AbortSignal.any()

I explored using AbortSignal.any(signals) instead of manual addEventListener calls. While it works for basic abort scenarios, it introduces subtle event-loop timing differences that cause the fetch adapter's stream-abort tests to fail (10 of 42 fetch tests hang). The composed signal's abort event fires in a different microtask queue compared to the direct listener approach, which changes the order of operations during stream abort handling. Until that's resolved upstream, the manual approach is more reliable.

Tests

All 45 relevant tests pass (3 composeSignals + 42 fetch adapter).

Summary by cubic

Refactors composeSignals to use an early-return pattern with small safety guards while keeping manual listener composition to preserve abort timing. No API or behavior changes.

Description

• Summary of changes
  • Early return: if (!timeout && !signals.length) return
  • Use const for AbortController
  • Initialize aborted = false
  • Guard unsubscribe to ignore double calls
  • Keep manual listeners instead of AbortSignal.any()
• Reasoning
  • Early returns simplify flow and reduce nesting
  • AbortSignal.any() changes event-loop timing and breaks stream-abort tests; manual listeners keep current behavior
• Additional context
  • Only lib/helpers/composeSignals.js is changed
  • Merged latest v1.x into this branch; no functional changes

Docs

• No API change; no docs required
• Optional note in /docs/ that composeSignals uses manual signal composition and an early-return guard for empty input

Testing

• No new tests
• All existing tests pass (3 composeSignals, 42 fetch adapter)
• No new tests needed; abort and timeout paths are covered

Semantic version impact

• Patch: internal refactor with no API or behavior changes

^{Written for commit e7b6bd5. Summary will update on new commits.}