[debabsah]

advise now warns when a markdown block's text runs past its bottom edge. Superset clips the overflow inside the block, or scrolls it, with no warning. A showcase dashboard's definitions block was cut off mid-section and nothing said so.

Added

• size.markdown-fit (warn or info, fixable). It estimates each markdown block's rendered height from its structure and width, and gives the overflow and the height it needs: "about 33 lines cut off at the bottom edge … it needs ~29.6 units at 12/12, has 10; raise the height".

  • What it reads: headings by level, setext headings, paragraphs and breaks, lists (tight, loose, nested), GFM tables, quotes, fenced code and rules. Lines wrap word by word with Inter's measured widths, and block margins collapse the way CSS does.
  • Two bounds:
    • The low bound is never more than any release drew; it decides whether the rule fires.
    • The high bound is never less, allowing for Windows scrollbars; --fix raises the height to it, rounded up to a fifth of a unit.
  • Severity: warn when text is cut on every release; info when only the last line or the padding reaches the edge, so the block scrolls a few pixels.
  • No fix for a header or footer a standard owns (reported only if text is cut), a block holding an image, or a block that would need more than 100 units. With a theme or CSS that sets type, the finding says it assumes Superset's default type.
  • Where it looks: layout rows, tabs, sub-tabs, headers and footers, allowing for the filter bar.

• layout.markdown-height now fixes a one-line block to its fitted height rather than a flat 2 units. The old target cut a # heading's padding, and on 4.1.4 and 5.0.0 a ## heading at 2 units overflowed by 1.4 px. This also covers the short-strip case: one line of text needs 1.6 units, ### 1.8, ## 2.2 (2.0 on 6.1.0) and # 2.4.

• Docs: blocks under 1 unit are documented as drawn at 40 px (GRID_MIN_ROW_UNITS). The spec still accepts them.

• Reads the dashboard's CSS (second commit). The estimate applies the spec's own dashboard CSS for markdown, then Superset's styles per release:

  • rules: those under .dashboard-markdown, with descendant, >, + and ~ combinators and :first-child, :last-child and :only-child;
  • properties: font size, line height, weight, letter and word spacing, margins, padding and borders, in px, em, rem or %;
  • cascade: !important, then specificity, then source order.

  Blocks are laid out as elements, with CSS margin collapsing. A finding now names only the CSS it can't read (another font family, attribute selectors and pseudo-elements, @media, var() or calc()), rather than assuming Superset's default type. On a real dashboard whose CSS changes type, the first commit warned falsely on a one-line footer and missed a block 47 px over; both now fall inside the bounds. The rule measures in a 1440 px wide window, so a fix holds at any wider width.

Calibration

• Corpus: 17 texts at 12, 8, 6, 4 and 3 twelfths on 4.1.4, 5.0.0 and 6.1.0 (headless Chromium, 1600 px), plus a 1,000-word text beside the filter bar. 4.1.4 and 5.0.0 render alike; 6.1.0's headings, lists, tables and quotes are spaced differently.
• Accuracy: at Superset's own styles the model matched 586 of 624 measured heights within 1.5 px; the cascade matched the computed style of all 570 elements measured; and a styled corpus of 14 blocks with its own stylesheet is recorded at 1440 and 1600 px on every release. The low bound never exceeded a measurement, and the high bound never fell short.
• Superset source cited:
  • holder padding: DashboardBuilder.tsx:326-332 at 4.1.4, :311-317 at 6.1.0;
  • overflow scrolls inside the block: Markdown.jsx:106-109, and Markdown/Markdown.tsx:126-130 at 6.1.0;
  • the 40 px floor: util/constants.ts:42.
• Reproducible: tools/record_markdown_fit.py records the fixture and reproduces it byte for byte. tools/ci_live_markdown_fit.py is a new step in the live CI job, on every release.

Tests

• Offline: 1874 passed, 1 skipped; params_drift --all and the rule table are clean. tests/test_markdown_fit.py checks both bounds against every measurement.
• Live: passes on 4.1.4, 5.0.0 and 6.1.0.
• Not verified: Linux Chromium (the new CI step is its first run) and real Windows (scrollbars emulated at 17 px).

Design brain 11

This collides with the integration branch's "10" from #38–#44. The numbers need reconciling at merge, as noted on those PRs.

Markdown inside sketch layouts exists only on feat/sketch-blocks (#41). Once that merges, this rule needs to read sketch legend blocks too.