fix: support 2GB base attachment uploads

[kongenpei]

Summary

Support base +record-upload-attachment for larger files by switching to Drive multipart upload above 20MB and keeping validation/output explicit for AI-agent use.

Changes

• use the shared Drive upload helpers so Base attachment uploads support multipart transfer and enforce the 2GB API limit
• add coverage for multipart uploads and over-limit validation, and update the lark-base reference doc

Test Plan

• Unit tests pass (make unit-test)
• Manual local verification confirms the lark-cli base +record-upload-attachment command works as expected (multipart upload succeeds for 20MB + 1 byte and exact 2GB; 2GB + 1 byte fails fast with exceeds 2GB limit)
• go mod tidy
• go run github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.1.6 run --new-from-rev=origin/main

Related Issues

• None

Summary by CodeRabbit

Release Notes

• New Features

  • Record attachment uploads now support files up to 2GB (increased from 20MB limit)

• Documentation

  • Updated documentation with new 2GB file size limit for record attachments
  • Added guidance on proper media file download procedures

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR extends base record attachment upload functionality to support files up to 2GB by integrating multipart upload capabilities. For files exceeding 20MB, the code now uses a multipart upload sequence (upload_prepare → upload_part → upload_finish) instead of the single-part endpoint, while maintaining backward compatibility with smaller files.

Changes

Cohort / File(s)	Summary
Multipart Upload Integration shortcuts/base/record_upload_attachment.go	Refactored attachment upload to conditionally use multipart sequence for files >20MB via shared helpers; increased max file size from 20MB to 2GB; added 2GB validation; delegated upload logic to common.UploadDriveMediaAll and common.UploadDriveMediaMultipart.
Test Coverage Expansion shortcuts/base/base_execute_test.go	Added test cases validating multipart upload behavior (multiple upload_part calls) for files exceeding 20MB threshold and 2GB validation boundary condition.
Documentation Update skills/lark-base/references/lark-base-record-upload-attachment.md	Updated file size limit documentation from 20MB to 2GB and added clarification that record attachment file tokens require docs +media-download instead of drive +download.

Sequence Diagram

sequenceDiagram
    participant Client
    participant BaseRecordUpload
    participant UploadHelper as Upload Helper
    participant DriveAPI as Drive API

    Client->>BaseRecordUpload: Upload attachment (fileSize, filePath)
    BaseRecordUpload->>BaseRecordUpload: Validate fileSize ≤ 2GB
    
    alt fileSize ≤ 20MB
        BaseRecordUpload->>UploadHelper: UploadDriveMediaAll()
        UploadHelper->>DriveAPI: POST /upload_all
        DriveAPI-->>UploadHelper: fileToken
    else fileSize > 20MB
        BaseRecordUpload->>UploadHelper: UploadDriveMediaMultipart()
        UploadHelper->>DriveAPI: POST /upload_prepare
        DriveAPI-->>UploadHelper: uploadId
        loop for each part
            UploadHelper->>DriveAPI: POST /upload_part
            DriveAPI-->>UploadHelper: partToken
        end
        UploadHelper->>DriveAPI: POST /upload_finish
        DriveAPI-->>UploadHelper: fileToken
    end
    
    UploadHelper-->>BaseRecordUpload: fileToken
    BaseRecordUpload->>Client: Updated record with attachment

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• feat: support multipart doc media uploads #294: Introduces the common.UploadDriveMediaAll and common.UploadDriveMediaMultipart helpers that this PR integrates into base record uploads.
• feat: support importing documents larger than 20MB #220: Implements multipart media upload sequence (upload_prepare → upload_part → upload_finish) with similar conditional dispatch logic for file size thresholds.

Suggested reviewers

• fangshuyu-768
• zgz2048

Poem

🐰 A rabbit hops with files so grand,
From twenty megs to two-gig land,
In pieces small they fly so fast,
Upload by upload, at last, at last! ✨📤

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description check	✅ Passed	The pull request description follows the required template with all main sections completed: Summary, Changes, Test Plan, and Related Issues.
Title check	✅ Passed	The title clearly and concisely captures the main change: enabling support for 2GB base attachment uploads through multipart upload functionality.

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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 codex/base-attachment-multipart-upload

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[github-actions]

🚀 PR Preview Install Guide

🧰 CLI update

npm i -g https://pkg.pr.new/larksuite/cli/@larksuite/cli@aae49d5d64bae61e16661945547480af3c8820cb

🧩 Skill update

npx skills add larksuite/cli#codex/base-attachment-multipart-upload -y -g