feat(im): support Markdown image rendering in post content

[liujiashu-shiro]

Summary

Leverage underlying URL compatibility and remove redundant URL conversion logic to simplify the Markdown-to-Post element processing pipeline. Also add documentation for sending Markdown images, and align image handling guidance with actual runtime behavior.

Changes

• Remove buildPostElements, buildPostElementNodes, scanPostToken, scanBareURLToken, scanMarkdownLinkToken, scanBalancedParenToken, trimBareURLToken, appendMDPostNode, marshalJSONNoEscape, marshalStringNoEscape and related constants
• Revert buildSingleMDPost / buildSegmentedPost to single {"tag":"md"} serialization
• Replace marshalJSONNoEscape with standard json.Marshal
• Remove corresponding unit tests
• Add Markdown image instructions in lark-im-messages-send.md and lark-im-messages-reply.md
• Align Markdown image documentation with runtime behavior: clarify that img_xxx keys are the most reliable input, local paths are not supported, and remote URLs are auto-resolved at runtime (removed with a warning on failure); recommend pre-uploading via images.create for reliability

Test Plan

• Unit tests pass (go test ./shortcuts/im/)
• Verify lark im send --markdown with bare URLs renders correctly
• Verify sending images via Markdown image syntax displays properly

Summary by CodeRabbit

• Documentation
  • Updated Markdown image handling guidance for messaging features to clarify that local file paths are not supported
  • Added recommendations to pre-upload images via images.create for improved reliability
  • Added workflow examples demonstrating best practices for referencing images in Markdown messages and replies
  • Clarified that remote URLs may be auto-downloaded/uploaded with possible removal on failure

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a88bc4fd-581d-4af9-8486-041306b585aa

📥 Commits

Reviewing files that changed from the base of the PR and between 52e0129 and ec827b6.

📒 Files selected for processing (4)

• shortcuts/im/helpers.go
• shortcuts/im/helpers_test.go
• skills/lark-im/references/lark-im-messages-reply.md
• skills/lark-im/references/lark-im-messages-send.md

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📝 Walkthrough

Walkthrough

This PR simplifies Feishu markdown post wrapping by consolidating tokenized inline elements into single md elements, replacing custom no-escape JSON marshaling with standard marshaling, removing URL and code-block decomposition helpers, and documenting the updated image handling constraints requiring pre-upload or remote URL resolution for --markdown replies and sends.

Changes

Markdown wrapping simplification and image documentation

Layer / File(s)	Summary
Markdown wrapping simplification shortcuts/im/helpers.go	Replaces custom no-escape JSON marshaling with json.Marshal, consolidates segmented post construction from multi-element decomposition (buildPostElementNodes) to single md elements, and removes tokenization/splitting helpers for URL and code-block preservation.
Test validation for plain markdown wrapping shortcuts/im/helpers_test.go	Rewrites TestWrapMarkdownAsPost to validate only the simplified plain markdown wrapping case, removing prior sub-tests for URL-to-link transformation and code-block URL preservation.
Image constraint documentation for messages-reply and messages-send skills/lark-im/references/lark-im-messages-reply.md, skills/lark-im/references/lark-im-messages-send.md	Clarifies markdown image handling across both skill references: documents pre-uploaded img_xxx keys as the recommended input, states local file paths in markdown syntax are not supported, notes remote URLs may be auto-downloaded/uploaded at runtime with removal on failure, and adds examples plus common-mistake warnings for image usage.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• larksuite/cli#206: Both PRs modify shortcuts/im/helpers.go markdown-to-Feishu post wrapping (wrapMarkdownAsPost), with this PR consolidating to single md elements via standard json.Marshal, whereas PR #206 tokenizes into mixed md/a elements with no-escape marshaling.
• larksuite/cli#338: Both PRs modify shortcuts/im/helpers.go's markdown-to-Feishu wrapping pipeline (e.g., wrapMarkdownAsPost and content builders), with this PR removing tokenization/splitting behavior compared to the segmentation refactoring in #338.

Suggested labels

domain/im, size/L

Suggested reviewers

• YangJunzhou-01
• fangshuyu-768

Poem

🐰 A simpler path for posts to take,
No tokens split, just md to make,
Pre-uploaded images shine so bright,
Local paths are out of sight,
The wrapping's clean—what a delight!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 12.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'feat(im): support Markdown image rendering in post content' clearly and concisely describes the main change—adding Markdown image rendering support to the IM feature.
Description check	✅ Passed	The pull request description includes all required template sections: Summary (motivation and scope), Changes (main modifications listed), Test Plan (verification steps with checkmarks), and Related Issues. Content is clear and specific.
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 feat/markdown_image

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[github-actions]

🚀 PR Preview Install Guide

🧰 CLI update

npm i -g https://pkg.pr.new/larksuite/cli/@larksuite/cli@ec827b6ccf1cfadb3edcc25bfab8d7bb33b72593

🧩 Skill update

npx skills add larksuite/cli#feat/markdown_image -y -g

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.87%. Comparing base (b0c9a4d) to head (ec827b6).
⚠️ Report is 13 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #893      +/-   ##
==========================================
- Coverage   65.90%   65.87%   -0.03%     
==========================================
  Files         518      520       +2     
  Lines       48830    49171     +341     
==========================================
+ Hits        32181    32391     +210     
- Misses      13882    14014     +132     
+ Partials     2767     2766       -1     

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