feat(test): add large conversation scenario for performance test

[cynthialong0-0]

Summary

Adds couple new performance tests for large chat sessions with ~60MB and 1400 messages.

Details

Test caes:

• time to load the large chat conversation
• after loading the large chat conversation, latency after typing keys in the input prompt
• time to execute a simple command echo hi
• time for scrolling the conversation under terminalBuffer and alternateBuffer rendering:
  • use telemetry metrics instead
  • update memory monitor to record cpu usage

Also update test rig to resolve the lint issue when reading the metrics from it.

Related Issues

Fixes #24865

How to Validate

Run npm run test:perf

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-cli]

Hi @cynthialong0-0, thank you so much for your contribution to Gemini CLI! We really appreciate the time and effort you've put into this.

We're making some updates to our contribution process to improve how we track and review changes. Please take a moment to review our recent discussion post: Improving Our Contribution Process & Introducing New Guidelines.

Key Update: Starting January 26, 2026, the Gemini CLI project will require all pull requests to be associated with an existing issue. Any pull requests not linked to an issue by that date will be automatically closed.

Thank you for your understanding and for being a part of our community!

[github-actions]

Size Change: +240 B (0%)

Total Size: 33.6 MB

Filename	Size	Change
./bundle/chunk-LLPFLZX5.js	0 B	-14.5 MB (removed)	🏆
./bundle/chunk-SQBFMKPC.js	0 B	-3.42 MB (removed)	🏆
./bundle/chunk-ZTU23GV4.js	0 B	-3.8 kB (removed)	🏆
./bundle/core-TQ5EBSLE.js	0 B	-46.6 kB (removed)	🏆
./bundle/devtoolsService-HKXTCH3V.js	0 B	-28.4 kB (removed)	🏆
./bundle/gemini-FLDXI7GG.js	0 B	-553 kB (removed)	🏆
./bundle/interactiveCli-ZLMYQ2QK.js	0 B	-1.29 MB (removed)	🏆
./bundle/oauth2-provider-KZ7BFYL7.js	0 B	-9.16 kB (removed)	🏆
./bundle/chunk-DK7P3JSC.js	14.5 MB	+14.5 MB (new file)	🆕
./bundle/chunk-SG66DMN6.js	3.8 kB	+3.8 kB (new file)	🆕
./bundle/chunk-VBS5BTAA.js	3.42 MB	+3.42 MB (new file)	🆕
./bundle/core-F2JHBW7J.js	46.6 kB	+46.6 kB (new file)	🆕
./bundle/devtoolsService-QSQXDITO.js	28.4 kB	+28.4 kB (new file)	🆕
./bundle/gemini-F55HK6WX.js	553 kB	+553 kB (new file)	🆕
./bundle/interactiveCli-SF5ESJSL.js	1.29 MB	+1.29 MB (new file)	🆕
./bundle/oauth2-provider-AAN5HLA3.js	9.16 kB	+9.16 kB (new file)	🆕

ℹ️ View Unchanged

Filename	Size	Change
./bundle/bundled/third_party/index.js	8 MB	0 B
./bundle/chunk-34MYV7JD.js	2.45 kB	0 B
./bundle/chunk-5AUYMPVF.js	858 B	0 B
./bundle/chunk-5PS3AYFU.js	1.18 kB	0 B
./bundle/chunk-664ZODQF.js	124 kB	0 B
./bundle/chunk-DAHVX5MI.js	206 kB	0 B
./bundle/chunk-IUUIT4SU.js	56.5 kB	0 B
./bundle/chunk-PC3Y4R7E.js	1.97 MB	0 B
./bundle/chunk-RJTRUG2J.js	39.8 kB	0 B
./bundle/cleanup-G6OHG6ZG.js	0 B	-932 B (removed)	🏆
./bundle/devtools-36NN55EP.js	696 kB	0 B
./bundle/dist-T73EYRDX.js	356 B	0 B
./bundle/events-XB7DADIJ.js	418 B	0 B
./bundle/gemini.js	4.97 kB	0 B
./bundle/getMachineId-bsd-TXG52NKR.js	1.55 kB	0 B
./bundle/getMachineId-darwin-7OE4DDZ6.js	1.55 kB	0 B
./bundle/getMachineId-linux-SHIFKOOX.js	1.34 kB	0 B
./bundle/getMachineId-unsupported-5U5DOEYY.js	1.06 kB	0 B
./bundle/getMachineId-win-6KLLGOI4.js	1.72 kB	0 B
./bundle/memoryDiscovery-R4AKKXHF.js	980 B	0 B
./bundle/multipart-parser-KPBZEGQU.js	11.7 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/client/main.js	222 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/_client-assets.js	229 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/index.js	13.4 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/types.js	132 B	0 B
./bundle/sandbox-macos-permissive-open.sb	890 B	0 B
./bundle/sandbox-macos-permissive-proxied.sb	1.31 kB	0 B
./bundle/sandbox-macos-restrictive-open.sb	3.36 kB	0 B
./bundle/sandbox-macos-restrictive-proxied.sb	3.56 kB	0 B
./bundle/sandbox-macos-strict-open.sb	4.82 kB	0 B
./bundle/sandbox-macos-strict-proxied.sb	5.02 kB	0 B
./bundle/src-QVCVGIUX.js	47 kB	0 B
./bundle/tree-sitter-7U6MW5PS.js	274 kB	0 B
./bundle/tree-sitter-bash-34ZGLXVX.js	1.84 MB	0 B
./bundle/cleanup-VCZE2KNQ.js	932 B	+932 B (new file)	🆕

_{compressed-size-action}

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a new set of performance tests designed to ensure the application remains responsive when handling exceptionally large conversation histories. By simulating real-world usage patterns such as loading, typing, and scrolling within a 60MB chat session, these tests help identify and prevent performance regressions in critical UI and interaction paths.

Highlights

• New Performance Test Suite: Added a comprehensive 'long-conversation' performance test suite to evaluate system behavior with large chat histories (~60MB, 1400 messages).
• Performance Metrics Coverage: Implemented tests for session loading, typing latency, command execution speed, and scrolling performance in both terminal and alternate buffers.
• Baseline Updates: Updated 'perf-tests/baselines.json' to include the new performance benchmarks for the long-conversation scenarios.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for GitHub and other Google products, sign up here.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request adds a performance test suite for long conversations, including scenarios for session resumption, typing, and scrolling, along with corresponding baseline data and mock responses. The feedback indicates that the scrolling tests are currently measuring the test runner's delays and the incorrect event loop rather than the CLI's performance, and suggests using the CLI's internal telemetry logs for more accurate results.

[jacob314]