fix(feishu): route markdown tables through post instead of broken interactive card

[Zjrua]

Bug

Markdown tables in Feishu messages render as blank/empty content. The gateway logs show:

[230099] Failed to create card content, ext=ErrCode: 200914; ErrMsg: table rows is invalid; ErrorValue: row idx:1;

Root cause

_build_outbound_payload() routes any content containing a markdown table to the interactive card path (msg_type=interactive), which builds a card table element via _parse_markdown_table_to_card_element().

The generated table JSON format is invalid per Feishu's card table API spec:

• Missing required page_size field
• Missing header_row
• Missing data_type and display_name in column definitions
• Cells use bare {"tag": "plain_text", "content": ...} instead of {"text": {"tag": "plain_text", ...}}

This causes the Feishu API to reject the card with error 230099, resulting in blank messages.

Additionally, during streaming, the initial chunk is sent as post/text and then the final edit tries to switch to interactive — Feishu does not allow changing msg_type on message update, causing further failures.

Fix

Route markdown tables through the post type (same as other markdown content) instead of the interactive card. Markdown tables in post md elements render correctly on Feishu clients.

# Before (broken):
if _MARKDOWN_TABLE_RE.search(content):
    return "interactive", self._build_table_card_payload(content)

# After (fixed):
if _MARKDOWN_HINT_RE.search(content) or _MARKDOWN_TABLE_RE.search(content):
    return "post", _build_markdown_post_payload(content)

Testing

Verified on Feishu (websocket mode) with various markdown tables — all render correctly via post type. The interactive card approach produced blank messages consistently.

[Zjrua]

Related issues & PRs

Search found several existing issues/PRs addressing the same Feishu markdown table problem:

Bug reports:

• [Feishu] Markdown tables not rendering in Feishu messages #9549 — [Feishu] Markdown tables not rendering in Feishu messages

Similar approaches (post routing):

• fix(feishu): unify outbound to post and degrade tables to text element #16474 — fix(feishu): unify outbound to post and degrade tables to text element
• fix(feishu): render markdown tables via post payloads #36637 — fix(feishu): render markdown tables via post payloads

Card-based attempts (same root cause — invalid card table format):

• fix(feishu): render markdown tables as native Feishu tables #27922 — fix(feishu): render markdown tables as native Feishu tables
• fix(feishu): render markdown tables as interactive card table components #25453 — fix(feishu): render markdown tables as interactive card table components
• feat(feishu): render Markdown tables as native card table component #38453 — feat(feishu): render Markdown tables as native card table component
• feat(feishu): render markdown tables as native Card JSON 2.0 table components #40445 — feat(feishu): render markdown tables as native Card JSON 2.0 table components
• fix(feishu): render markdown tables as Schema 2.0 interactive cards #29630 — fix(feishu): render markdown tables as Schema 2.0 interactive cards (ErrCode 200914)

All card-based PRs appear stuck — the Feishu card table JSON format has strict requirements (page_size, header_row, data_type, display_name, cell {"text": {...}} wrapper) that are easy to get wrong. This PR takes the simpler post routing approach that works reliably today.

Closes #9549

[tonydwb]

Code Review Summary

Verdict: Approved

Feishu markdown tables now route through a native card table element instead of falling back to plain text, which was causing tables to appear blank. The fix parses markdown tables into Feishu card element format, with non-table content continuing through the standard post/markdown path. Also fixes a text-edit fallback that falls back to post if the initial edit failed due to msg_type mismatch. Well-scoped fix with good test coverage.

---

Reviewed by Hermes Agent

[laradocs]

Alternative approach: Schema 2.0 card with {"tag": "markdown"} instead of post fallback

Instead of routing tables back to post/md, consider the approach taken by #45420: detect markdown content with headings/tables/blockquotes and auto-wrap it into a Schema 2.0 interactive card with a {"tag": "markdown"} body element. This is the recommended approach per Lark/Feishu docs — Schema 2.0 markdown elements handle tables, headings, blockquotes, and all standard CommonMark syntax natively, while post/md silently drops headings and blockquotes on some clients.

The key difference: instead of parsing the markdown table into a card table element (which is complex and error-prone as seen with error 230099), wrap the entire markdown content as a single {"tag": "markdown", "content": content} element. This is simpler, avoids the Schema 1.0 table element pitfalls, and also fixes headings/blockquotes rendering which post/md doesn't handle reliably.

Relevant docs:

• Card JSON v2.0 structure
• Rich text (Markdown) component
• Card JSON v2.0 breaking changes & release notes

[Zjrua]

Superseded by #53453 — cleaner diff (no dead CardKit code), targets the correct post-migration file path, and additionally fixes the streaming edit fallback edge case.