Fix ?? (nullish coalescing) earlyOut to not short-circuit on falsy values

[phillipc]

Summary

The ?? operator's earlyOut was a => a, identical to ||. This caused ?? to short-circuit on falsy values like 0, '', and false, which is incorrect — ?? should only short-circuit when the value is not null and not undefined.

Detected in #297

Fix

-operators['??'].earlyOut = a => a
+operators['??'].earlyOut = a => a !== null && a !== undefined

Verification

All 404 parser tests pass. Full suite (5371 tests) passes.

Summary by CodeRabbit

• Bug Fixes
  • Fixed nullish coalescing operator behavior to correctly handle null and undefined values separately from other falsy values.

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 29b93105-6f18-4528-875f-2d1bf61bb9cd

📥 Commits

Reviewing files that changed from the base of the PR and between b47ab8c and c547a64.

📒 Files selected for processing (1)

• packages/utils.parser/spec/nodeBehaviors.ts

📝 Walkthrough

Walkthrough

Modified the ?? operator's earlyOut behavior in the parser operators module. The operator now correctly returns input only when it is neither null nor undefined, aligning early-exit semantics with nullish coalescing logic.

Changes

Cohort / File(s)	Summary
Nullish Coalescing Operator Logic packages/utils.parser/src/operators.ts	Updated earlyOut condition for ?? operator from unconditional return to conditional return based on nullish check (a !== null && a !== undefined).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Suggested reviewers

• brianmhunt

Poem

🐰 A whisker-twitch of logic refined,
The ?? now sees what's null, undefined,
No falsy foes will pass its gate,
Only true nothingness meets its fate! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: fixing the ?? operator's earlyOut behavior to properly handle nullish coalescing instead of short-circuiting on all falsy values.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/nullish-coalescing-earlyout

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[brianmhunt]

👍 test added