#mermaid.mbt

///|
test {
  let svg = @mermaid.render(
    (
      #|pie title Pets adopted by volunteers
      #|    "Dogs" : 386
      #|    "Cats" : 85
      #|    "Rats" : 15
    ),
  )
  assert_true(svg.has_prefix("<svg id=\"mermaid-svg\""))
  assert_true(svg.contains("Pets adopted by volunteers"))
}

#Status

#Gantt charts and time

• the time zone, which is that of the reference machine (Asia/Shanghai, with its historical offsets) — @jsdate.Zone::reference() is the one place that chooses it;
• the present, for the today marker and for dates that leave parts out: now, in milliseconds, defaulting to the system clock;
• the page the diagram sits in, whose width the chart takes and whose scrollbar changes how labels measure: page.

#Flowcharts and the unified renderer

• ELK, the default, computed by bobzhang/elk, a fork of moon_elk with the fixes it needs to match elkjs 0.9.3, until they are merged upstream;
• dagre (internal/dagre), for layout: dagre and for layout names mermaid does not register;
• the swimlane engine (internal/swimlane), for layout: swimlane;
• cose-bilkent (internal/cose), the default of mindmaps.

• rough.js places the control points of every line at random. With handDrawnSeed set, the port (internal/rough) reproduces upstream exactly; without a seed upstream's own output differs from render to render, and the port's is merely equivalent. Upstream draws some shapes (stadium, flag, documents, ...) through rough.js even in the classic look.
• Icon packs cannot be registered: every icon is drawn as mermaid's unknown icon, which is also what upstream draws without packs.
• Images take their size from the image. render never touches the network: it reads data: URLs itself and asks the caller's optional image_loader for other addresses (PNG, GIF, JPEG, WebP and SVG sizes are decoded as Chrome decodes them). Without a loader it draws such an image only when the node gives w and h without a constraint, and raises Unsupported otherwise. The CLI's --fetch-images is such a loader.
• Markdown labels cover paragraphs, emphasis, strikethrough, escapes, HTML blocks and inline HTML; other markdown blocks pass through as text.
• Line breaking inside labels knows Blink's rules for ASCII text; other scripts break at spaces only.

#How "byte-identical" is checked

• scripts/oracle.py renders a diagram with that reference.
• scripts/compare.py keeps a reference SVG next to every testdata/**/*.mmd and diffs the port against it.
• moon test --target native runs the same comparison from tests/.
• scripts/check_examples.py does it for the examples in upstream's own documentation.

#Layout