Commit graph

1 commit

Author SHA1 Message Date
Teknium
1d00716754
fix(cli,tui): align CJK / wide-char markdown tables (#23863)
CJK and emoji glyphs render as two terminal cells but JS String#length
and the model's own padding count them as one, so any markdown table
with Chinese / Japanese / Korean cells drifts right per row when a
real terminal renders it. Both surfaces fix this with a display-cell
width measurement (wcswidth on the Python side, stringWidth on the
TUI side).

Changes:
- agent/markdown_tables.py: new helper. realign_markdown_tables(text)
  detects markdown table blocks (header + |---| divider) and
  rewrites the row padding using wcwidth.wcswidth so every pipe and
  dash lines up across rows. No-op on text without tables.
- cli.py: hook the helper into _render_final_assistant_content for
  strip / render modes (raw passes through untouched), and into the
  streaming line emitter so live token-by-token rendering also
  produces aligned tables. A small two-buffer state machine in
  _emit_stream_text holds table rows until the block ends, then
  flushes them through the realigner so all rows pad to a single
  per-column width.
- ui-tui/src/components/markdown.tsx: renderTable now uses
  stringWidth (Bun.stringWidth fast path + East-Asian-width-aware
  fallback, already memoised in @hermes/ink) instead of UTF-16
  String#length for both column-width measurement and per-cell
  padding. Drops the comment that documented the bug as a deliberate
  limitation.

Validation:
- New tests/agent/test_markdown_tables.py (11): every rebuilt block
  shares pipe column offsets across rows for pure CJK, mixed
  CJK+emoji, ragged-row, and multi-table inputs.
- Updated tests/cli/test_cli_markdown_rendering.py: the existing
  strip-mode test asserted exact whitespace; rewritten to assert the
  alignment contract (cell content survives + every rendered row
  shares pipe offsets).
- New ui-tui markdown.test.ts case (1): rendered column-2 start
  offset is identical for the header + every body row, including
  the CJK row that drifted before the fix.
- Live: hermes chat -q with the user-reported screenshot prompt now
  produces a perfectly aligned table on the wire (header, divider,
  4 body rows including '通义千问', all pipes at identical columns).
2026-05-11 11:13:06 -07:00