fix(cli): po loader push performance, multi-entry sections, pseudo mode crash

[AndreyHirsa]

Summary

Fix PO loader push crashing on large files, missing entries in multi-entry sections, and pseudo mode crash due to missing validateSettings.

Changes

• Fixed push parsing the entire target file for every section
• Fixed push only translating the first entry when multiple entries share a section without blank lines between them
• Added missing validateSettings to pseudo localizer so --pseudo mode no longer crashes

Testing

Business logic tests added:

• Multi-entry section push translates all entries
• All 18 PO loader tests pass locally

Visuals

N/A - no UI changes

Checklist

• Changeset added (if version bump needed)
• Tests cover business logic (not just happy path)
• No breaking changes (or documented below)

Summary by CodeRabbit

• Bug Fixes
  • Improved PO loader push performance
  • Fixed multi-entry section handling in PO files
  • Resolved crash in pseudo mode

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR delivers a patch release for lingo.dev that addresses PO loader push performance, fixes multi-entry section handling, and resolves a pseudo mode crash. Changes include optimizations to the push operation, a new test case validating multi-entry translations, and an addition to the pseudo localizer's interface.

Changes

Cohort / File(s)	Summary
Release & Changelog .changeset/light-shrimps-hear.md	New changeset entry documenting patch release with fixes for PO loader push performance, multi-entry section handling, and pseudo mode crash.
PO Loader Tests packages/cli/src/cli/loaders/po/index.spec.ts	Added test case verifying push() correctly translates multiple msgid/msgstr pairs in a contiguous PO section without blank line separators.
PO Loader Implementation packages/cli/src/cli/loaders/po/index.ts	Refactored push logic: lazy-initialized currentSections, improved section matching fallback, changed merge behavior to handle multiple entries, and introduced resolveTargetHeaders() helper for conditional header extraction.
Pseudo Localizer packages/cli/src/cli/localizer/pseudo.ts	Added validateSettings async method to pseudo localizer interface, resolving to { valid: true }.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

• fix(cli): guard against empty translations in PO loader #2000 — Both PRs refactor the currentSections resolution and merge logic in the PO loader push operation, with related changes to section matching and translation handling.

Suggested reviewers

• cherkanovart
• ohmoses

Poem

🐰 With whiskers and optimized code,
We polish the PO loader's mode,
Multi-entries now blend with grace,
Pseudo crashes vanish without trace! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 16.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the three main fixes in the changeset: PO loader push performance, multi-entry sections handling, and pseudo mode crash.
Description check	✅ Passed	The description includes all required sections: summary, changes, testing, visuals, and checklist. All key changes are documented with business logic tests added and confirmed to pass.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/po-loader-push-and-pseudo-mode

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[coderabbitai]

🧹 Nitpick comments (1)

packages/cli/src/cli/loaders/po/index.ts (1)

66-86: Verify the section-matching logic for header-only sections.

Inside the if (!msgid) block, msgid is undefined. Line 83 compares csMsgid === msgid, which effectively checks csMsgid === undefined. This appears intentional for matching header-only sections, but the logic could be clearer.

Consider adding a comment to clarify the intent:

               const csMsgid = Object.keys(csEntries).find(
                 (key) => csEntries[key].msgid,
               );
+              // Match sections that both lack a real msgid (header-only sections)
               return csMsgid === msgid;

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@packages/cli/src/cli/loaders/po/index.ts` around lines 66 - 86, The matching
branch using if (!msgid) currently compares csMsgid === msgid (i.e., ===
undefined) to detect header-only sections; update the block around
currentSections/currentSection to make the intent explicit by either changing
the comparison to check for absence of csMsgid (e.g., csMsgid == null) or adding
a clear inline comment explaining that csMsgid === undefined is intentionally
used to match header-only PO sections, referencing msgid, csPo, csContextKey,
csEntries and csMsgid so future readers understand this special-case logic.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@packages/cli/src/cli/loaders/po/index.ts`:
- Around line 66-86: The matching branch using if (!msgid) currently compares
csMsgid === msgid (i.e., === undefined) to detect header-only sections; update
the block around currentSections/currentSection to make the intent explicit by
either changing the comparison to check for absence of csMsgid (e.g., csMsgid ==
null) or adding a clear inline comment explaining that csMsgid === undefined is
intentionally used to match header-only PO sections, referencing msgid, csPo,
csContextKey, csEntries and csMsgid so future readers understand this
special-case logic.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a7f9564e-aba7-42b0-bb91-345613734c81

📥 Commits

Reviewing files that changed from the base of the PR and between e490347 and 0b6247b.

📒 Files selected for processing (4)

• .changeset/light-shrimps-hear.md
• packages/cli/src/cli/loaders/po/index.spec.ts
• packages/cli/src/cli/loaders/po/index.ts
• packages/cli/src/cli/localizer/pseudo.ts