refactor(assistant): use retry library for backoff loops

[omarluq]

No description provided.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: fe723d85-950c-44a4-b8b8-929254324a45

📥 Commits

Reviewing files that changed from the base of the PR and between 40e9f99 and 33b75c0.

📒 Files selected for processing (5)

• go.mod
• internal/assistant/retry.go
• internal/assistant/retry_internal_test.go
• internal/assistant/runtime_model.go
• internal/assistant/runtime_test.go

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📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Refactored internal retry mechanism to use exponential backoff with configurable maximum delays, improving reliability during recovery from transient failures and provider errors.
  • Enhanced error handling to better classify and manage retriable errors.
  • Updated test coverage for retry behavior and backoff calculations.

Walkthrough

The PR migrates the assistant retry mechanism from a manual exponential backoff loop to the github.com/sethvargo/go-retry library. It adds retryFailedError and retryableProviderError error types, replaces retryDelay/waitForRetry with retryBackoff, and decomposes completeWithRetry into retryAttempt, completeAttempt, retryError, and retryResultError helpers. go-retry is promoted from indirect to direct dependency.

Changes

Assistant Retry Library Migration

Layer / File(s)	Summary
Retry primitives: error types and backoff builder go.mod, internal/assistant/retry.go, internal/assistant/retry_internal_test.go	Promotes go-retry to a direct dependency. Adds retryFailedError and retryableProviderError wrappers. Replaces retryDelay/waitForRetry with retryBackoff (capped exponential via retrylib) and maxRetryDelays. Updates unit tests from TestRetryDelayIsCapped/TestWaitForRetryRespectsCancellation to TestRetryBackoffUsesCappedExponentialDelays.
Runtime retry orchestration and helper decomposition internal/assistant/runtime_model.go, internal/assistant/runtime_test.go	Rewrites completeWithRetry to drive retries via retrylib.Do with the backoff callback. Adds retryAttempt (per-attempt execution + retryability gating), completeAttempt (single provider RPC + event emission), retryError (unwraps retry failures), and retryResultError (maps cancellation/deadline to retry_canceled). Updates runtime test to cancel only on StreamEventToolResult.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• omarluq/librecode#42: Shares changes to internal/assistant/retry.go and the TestShouldRetryModelErrorTreatsHTTP2StreamErrorsAsTransient test, which remains present unchanged in this PR's diff.
• omarluq/librecode#46: Both PRs modify ShouldRetryModelError and the retryable error classification logic in internal/assistant/retry.go, overlapping at the core retry decision point.
• omarluq/librecode#87: Directly tied to this PR's refactor of completeWithRetry and context-window retryability decisions in runtime_model.go.

Poem

🐇 Hop, hop, the old loop's gone away,
retrylib now schedules each delay,
Exponential caps keep waits in line,
retryAttempt helpers work just fine.
No more manual ticks and timer dread—
The rabbit lets the library lead instead! 🎉

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❓ Inconclusive	No pull request description was provided by the author, making it impossible to evaluate whether the description relates to the changeset.	Add a pull request description explaining the motivation, implementation details, and any breaking changes or migration notes for this retry library refactoring.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: refactoring the assistant module to use a retry library for backoff loops instead of custom retry logic.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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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 chore/retry

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[codecov]

Codecov Report

❌ Patch coverage is 88.09524% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.44%. Comparing base (40e9f99) to head (33b75c0).

Files with missing lines	Patch %	Lines
internal/assistant/runtime_model.go	90.16%	4 Missing and 2 partials ⚠️
internal/assistant/retry.go	82.60%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #144      +/-   ##
==========================================
+ Coverage   80.40%   80.44%   +0.04%     
==========================================
  Files         277      277              
  Lines       21898    21925      +27     
==========================================
+ Hits        17607    17638      +31     
+ Misses       3079     3075       -4     
  Partials     1212     1212              

Flag	Coverage Δ
unittests	80.44% <88.09%> (+0.04%)	⬆️

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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