[UtkarshUsername]

Problem

Colored command output parses SGR parameters even when the resulting style is already cached.

Change

Check the existing style-transition cache before parsing. Cache misses and cursor/erase commands keep their existing behavior. Extend the chunk-boundary test with repeated bold, reset, and RGB styles.

Scope and approval

Submitted under CONTRIBUTING.md's small, focused fix exception. The defect is redundant parsing and allocation on cache hits, where the cached result is already available. This fix only moves the existing cache lookup ahead of that work, preserving terminal output, command handling, and cache limits. It adds no feature or intentional product behavior change, so no prior issue or maintainer approval is being claimed or relied on.

Verification

Per colored-output replay	Before	After
Median parser time	21.159 ms	17.565 ms (17.0% lower)
Sampled allocated bytes	24,106,875	21,194,616 (12.1% lower)
Numeric parses, cold cache	12,948	4
Numeric parses, warm cache	12,948	0

Timing and allocation figures are from dot's original benchmark: Node 26.12.1 on Linux x64, ~262K characters of colored output replayed in 4,096-character chunks. Timing used five alternating before/after process pairs with baseline controls (maximum paired baseline difference: 12.3%); allocation used three separate sampled profiles per version. These measure parser throughput and temporary allocations, not whole-app latency or retained memory.

• A ~262 KB colored replay reduces numeric parses from 12,948 to 4 cold / 0 warm, reproduced locally on Node 26.12.1.
• 16 parser tests and the client reducer test pass; 16,619 full-state comparisons match the baseline, including split escapes, truncation, Unicode, cursor controls, and cache eviction.
• Formatting, lint, whitespace checks, and the shared package typecheck pass.

Original implementation: OpenAI dot / ChatGPT Work cloud agent (exact model unavailable). Verified with gpt-6.1-sol through Codex in T3 Code.

[macroscopeapp]

Approvability

Verdict: Approved at 0a549c8

Macroscope's review found this PR approvable — Cached terminal styles now bypass redundant parameter parsing while retaining existing cache limits and command handling. This is a narrowly scoped performance optimization with no apparent material change to user-visible behavior.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review.

Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: main
• File: .coderabbit.config.ts
• Commit: 7a4f5b6
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: f7fcc8e4-5de5-45f9-8198-bf12cdccd363

Commits

Reviewing files that changed from the base of the PR and between 7a4f5b6 and 0a549c8.

Files selected for processing: 2

• packages/shared/src/terminalOutput.test.ts
• packages/shared/src/terminalOutput.ts

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 9 remain after this review.

Walkthrough

The CSI handler now processes SGR sequences before calculating parameters for other CSI commands. The chunk-splitting test checks output consistency across additional terminal sequences and two maxChars values.

Changes: Terminal output processing

Layer / File(s)	Summary
SGR handling and chunk-split validation packages/shared/src/terminalOutput.ts, packages/shared/src/terminalOutput.test.ts	Terminal.csi handles SGR sequences before calculating parameters for other CSI commands. The test compares whole-input output with every two-chunk split at maxChars values 3 and 1_024.

Priority: Low

Estimated code review effort: 2 (Simple) | ~8 minutes

Change: Refactor

Possibly related issues

• pingdotgg/t3code issue 9661: The change avoids cursor and erase parameter calculations for SGR sequences, but it does not add hidden-thread gating.

Suggested reviewers: maria-rcks

Merge Risk: Minimal · up to 0a549

This narrowly scoped performance change has no confirmed behavioral or merge-blocking risk.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly and concisely describes the main performance change: skipping parsing for cached terminal styles.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Description check		The description includes all required sections: Problem, Change, Scope and approval, and Verification. It explains the defect, the implementation, the small-fix approval exception, measured results, f…

Full details: Description check

Explanation

The description includes all required sections: Problem, Change, Scope and approval, and Verification. It explains the defect, the implementation, the small-fix approval exception, measured results, focused tests, environment details, and checks that could not be completed.

Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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[maria-rcks]

Note

Written by gpt-6.1-sol on behalf of Maria

Verified in a real dev environment

verified unchanged head 0a549c82ee12f18358d799c8c0b8c709cbad7464 against github/main at 8b74a69019 on this linux boat vm. installed dependencies in both checkouts and ran one dev server at a time with isolated, initially empty state. used repository playwright and /usr/bin/google-chrome to add the real repository as a project, create threads, select codex gpt-6.1-sol, send real turns, and expand their shell-command output. no mocks, replay provider, or seeded data.

chrome precise coverage during the first expansion of the same real command output reproduced the redundant parsing on main and confirmed the changed path on this head:

                               main       pr head
Terminal.csi calls               52             52
csiParams calls                 52              8
rendered output text            identical
rendered output styled HTML     identical

repeated bold red, true-color rgb, plain/reset output, blue, and a split green escape rendered correctly. nearby behavior also passed: carriage-return plus erase-line replaced progress old with progress done; cursor-left changed abcdef to abcXYZ; stderr appeared; collapse/reopen and page reload preserved the output and styles. a second real command with six delayed colored lines, stderr, and progress replacement completed correctly.

blacksmith-check run --id <task-owned-worker> \
  'vp i && vp test run packages/shared/src/terminalOutput.test.ts packages/client-runtime/src/state/commandOutput.test.ts'
2 files passed; 17 tests passed

no source changes or pushes were needed. github checks on the tested head have no failures or pending checks.

Not verified

native electron, ios/android, macos/windows, other providers, and relay/tunnel connections were not exercised. this verification measures parser calls through the real web client; it does not establish whole-app latency or allocation improvements. independent cache-eviction stress and live per-chunk rendering were not measured in the real app. uploaded video playback and seeking were checked in chrome.