The expressiveness gap traced to vocabulary: draw.io has hundreds of shapes,
the declarative layer allowed six. Opening it, with the failure modes from
design review handled:
- shapes.ts: a ~20-entry curated catalog (full style fragment incl. the
matching perimeter — required or edges connect to the bounding box; a
text-scale factor verified in the real editor — the same sentence overflows
a 1.0x rhombus and fits a 1.5x one; labelOutside+glyph for umlActor-style
figures). Any other token passes through verbatim: draw.io degrades unknown
shapes to rectangles safely (verified). Injection-capable tokens (;/=) are
rejected outright.
- Pass-through emits a WARNING with a nearest-catalog hint (bounded edit
distance), so a typo'd 'cyclinder' is a one-turn fix instead of a silently
rectangular node forever. set_shape/set_role/set_group operations make the
fix possible without remove+re-add (which would drop links).
- mergeStyle(): style fragments merge per-key (later wins, bare shape classes
displace each other) instead of string concatenation. This is what makes
shape and theme composable by rule — shape owns geometry keys, theme owns
colour/type keys, and an overlap resolves by order instead of emitting
contradictory duplicates.
- dai_shape marker carries the declared token through the round trip:
appearance-based reverse mapping cannot distinguish aliases (diamond vs
decision) or a rotated queue from a cylinder.
- dai_auto marker separates engine-measured size from user-fixed size: parsed
boxes no longer freeze the first layout's numbers, so changing a label
re-measures. Pinned nodes keep everything, as before.
- draw_graph's closed shape enum opened to match (first instance of the
schema-drift problem the review predicted).
14 new tests: merge ownership, injection rejection, near-match hints,
alias-preserving round trip, re-measure on label change, mxgraph.* tokens
staying boxes with role/group intact. 556 unit tests green; acceptance
diagram (person/hexagon/cylinder/queue/cloud/decision/callout) verified in
the real editor.
