fix(assistant): persist failed stream progress

[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

Run ID: 2cdc346b-3028-450b-85f7-9ef0cf6c4b55

📥 Commits

Reviewing files that changed from the base of the PR and between d3d4235 and 540c884.

📒 Files selected for processing (2)

• internal/assistant/runtime.go
• internal/assistant/runtime_test.go

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes

  • Improved handling of transient HTTP/2 stream and provider errors to enable automatic retry.

• New Features

  • Partial assistant output is now captured and saved when model calls fail, preventing loss of progress.

• Tests

  • Added test coverage for HTTP/2 stream error resilience and partial progress persistence on provider failures.

Walkthrough

This PR expands transient error detection for provider messages and captures partial streamed assistant output during prompt execution, persisting accumulated blocks and appending a custom error message when provider streaming fails.

Changes

Partial Progress Persistence on Transient Errors

Layer / File(s)	Summary
Extended retryable error patterns internal/assistant/retry.go, internal/assistant/retry_internal_test.go	New error substrings (internal_error, stream error, stream id, received from peer, http2) are classified as transient/retryable. A new test validates HTTP/2 stream internal errors are treated as transient.
Partial progress buffering and persistence implementation internal/assistant/runtime.go, internal/assistant/runtime_lifecycle_test.go	The Prompt method now routes through respondWithPartialProgress, which buffers streamed output blocks (merging adjacent assistant/thinking deltas), supports retry snapshot/reset, and persists accumulated partial blocks and a RoleCustom error message on provider failure using errors.Join. Lifecycle expectations updated to include message_append during error flows.
Test coverage for partial progress persistence internal/assistant/runtime_test.go	A shared recoveredResponseText constant unifies recovery assertions. Adds TestRuntime_PromptRetriesProviderStreamError, a partialFailureCompletionClient test stub that streams events then fails, and TestRuntime_PromptPersistsPartialProgressOnProviderFailure to validate persisted message roles and contents after partial streaming plus provider failure.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰 I buffered words mid-stream, a careful hare,
When HTTP2 stuttered, I kept a spare—
Partial thoughts saved, so nothing's lost,
On retries swift, we count the cost.
A stitched-together message, warm and neat.

🚥 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, so the check cannot evaluate whether the description relates to the changeset.	Provide a description explaining the changes, such as the retry behavior for stream errors and persistence of partial progress during failures.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix(assistant): persist failed stream progress' accurately and concisely summarizes the main change: persisting partial assistant output when model calls fail due to stream errors.
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 fix/retry-stream-errors-only

---

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 87.75510% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.31%. Comparing base (ec4b5d5) to head (540c884).

Files with missing lines	Patch %	Lines
internal/assistant/runtime.go	87.09%	7 Missing and 5 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #42      +/-   ##
==========================================
+ Coverage   60.16%   60.31%   +0.14%     
==========================================
  Files         168      168              
  Lines       16665    16755      +90     
==========================================
+ Hits        10027    10105      +78     
- Misses       5628     5635       +7     
- Partials     1010     1015       +5     

Flag	Coverage Δ
unittests	60.31% <87.75%> (+0.14%)	⬆️

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@internal/assistant/runtime.go`:
- Around line 358-365: The current partialPromptProgress.append method drops
chunks consisting only of whitespace because it uses strings.TrimSpace(content);
change the early-return check to only skip truly empty strings (e.g., content ==
"" or len(content) == 0) so whitespace-only deltas are preserved; keep the
existing merge logic that appends content into
progress.blocks[lastIndex].Content and continue to use
canMergePartialPromptBlock(role) — i.e., remove the TrimSpace filtering so
partialPromptProgress.append, progress.blocks and canMergePartialPromptBlock are
left intact but whitespace content is not discarded.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 9016ff19-a2a8-4193-b260-25c8242c8013

📥 Commits

Reviewing files that changed from the base of the PR and between ec4b5d5 and d3d4235.

📒 Files selected for processing (5)

• internal/assistant/retry.go
• internal/assistant/retry_internal_test.go
• internal/assistant/runtime.go
• internal/assistant/runtime_lifecycle_test.go
• internal/assistant/runtime_test.go

[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

See analysis details on SonarQube Cloud