fix: AutoGen 'No next batch available' when next batch is ready

[ChuxiJ]

navigate_to_next_batch relied on a stale total_batches Gradio state to decide whether a next batch exists. The background generator updates total_batches after navigate_to_next_batch runs in the .then() chain, so the guard check blocked valid navigation.

Changes:

• batch_navigation.py: derive total_batches from batch_queue length (mirrors navigate_to_previous_batch which already did this).
• batch_management.py: fix early-return path in generate_next_batch_background to update total_batches when the next batch was already completed.
• batch_navigation_test.py: add 3 focused unit tests.

Summary by CodeRabbit

• Bug Fixes

  • Improved batch tracking to ensure completed batches are reflected accurately without delay
  • Enhanced batch navigation to safely handle asynchronous queue updates and prevent reliance on outdated batch counts

• Tests

  • Added comprehensive unit tests for batch navigation, covering edge cases with stale batch counts and missing batches

[coderabbitai]

📝 Walkthrough

Walkthrough

The changes introduce defensive updates to batch management and navigation functions to handle stale total_batches values. When new completed batches are observed in the queue, total_batches is updated accordingly. New tests validate the stale total_batches scenario and existing guard logic.

Changes

Cohort / File(s)	Summary
Batch State Management acestep/ui/gradio/events/results/batch_management.py, acestep/ui/gradio/events/results/batch_navigation.py	Adds defensive logic to update total_batches when completed batches are discovered in the queue. batch_management.py ensures total_batches reflects newly observed completed batches; batch_navigation.py computes total_batches as the maximum of the provided value and current queue length to prevent reliance on stale values.
Test Coverage acestep/ui/gradio/events/results/batch_navigation_test.py	New unit test module for batch navigation logic, covering stale total_batches scenarios, last-batch detection, and missing batch handling. Tests validate defensive guard logic using mocked Gradio helpers.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 Hops with glee through batches bright,
No stale counts shall block our sight!
Queue's true length now takes the floor,
Navigation runs forevermore! 🎉

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the main issue (stale total_batches causing false 'No next batch available' error) and the fix (handling ready next batches), accurately reflecting the primary changes across all modified files.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/autogen-next-batch-stale-total-batches

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[coderabbitai]

🧹 Nitpick comments (1)

acestep/ui/gradio/events/results/batch_navigation_test.py (1)

28-36: Consider renaming kw to _kw or **_ to signal intentional discard.

The **kw in the lambda is necessary to accept keyword arguments (e.g., n=new_idx + 1) passed to t(), but since it's unused in the return value, prefixing with _ makes the intent clearer and silences the linter.

♻️ Suggested fix

-@patch("acestep.ui.gradio.events.results.batch_navigation.t", side_effect=lambda key, **kw: key)
+@patch("acestep.ui.gradio.events.results.batch_navigation.t", side_effect=lambda key, **_kw: key)

🤖 Prompt for AI Agents

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

In `@acestep/ui/gradio/events/results/batch_navigation_test.py` around lines 28 -
36, Rename the unused lambda keyword-args parameter in the patch on t() to
indicate intentional discard: change the side_effect lambda in the `@patch` on
"acestep.ui.gradio.events.results.batch_navigation.t" from "lambda key, **kw:
key" to use a prefixed/underscore parameter like "lambda key, **_kw: key" (or
"**_:") so the intent is clear to readers and linters; keep the rest of
NavigateToNextBatchTests and its helper _run_first_yield unchanged.

🤖 Prompt for all review comments with AI agents

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

Nitpick comments:
In `@acestep/ui/gradio/events/results/batch_navigation_test.py`:
- Around line 28-36: Rename the unused lambda keyword-args parameter in the
patch on t() to indicate intentional discard: change the side_effect lambda in
the `@patch` on "acestep.ui.gradio.events.results.batch_navigation.t" from "lambda
key, **kw: key" to use a prefixed/underscore parameter like "lambda key, **_kw:
key" (or "**_:") so the intent is clear to readers and linters; keep the rest of
NavigateToNextBatchTests and its helper _run_first_yield unchanged.