SVG renderer loses nesting for deeply nested if-fragments

[MrCoder]

Summary

When if-fragments are nested three levels deep, the SVG renderer flattens the innermost nesting instead of preserving it. The HTML renderer handles this correctly.

Reproduction

DSL:

if(x) {
  if(y) {
    if(z) {
      A.method()
    }
  }
}

Expected (HTML renderer behaviour): Three visually nested if-fragment boxes — if(z) inside if(y) inside if(x).

Actual (SVG renderer behaviour): if(z) is rendered at the same visual level as if(y) instead of being nested inside it.

Impact

Diagrams with triple-nested conditionals are rendered incorrectly in the SVG output path.

Environment

• Renderer: SVG only (HTML is correct)
• Reproducible via compare-case tool: /e2e/tools/compare-case.html?case=edge-nested-if-triple
• Edge case key in e2e/data/compare-cases.js: edge-nested-if-triple

[MrCoder]

📸 Screenshots available locally in .playwright-mcp/screenshots/ (zenuml-core project directory).

Screenshot: ss-edge-nested-if-triple-full.png (HTML nests correctly, SVG flattens)

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[MrCoder]

Fix implemented

Commit: 899390bf — fix(svg): correct triple-nested fragment x-position flattening

Root cause: Mutation-during-iteration bug in src/svg/buildGeometry.ts. The spatial nesting-depth computation loop shifted fragment.x values while still iterating, causing later containment checks to fail. When processing the innermost if(z), the middle if(y) had already been shifted 10px right, so the check outer.x <= inner.x returned false and if(z) got nestDepth=1 instead of 2.

Fix: Split the single loop into two passes:

1. Compute all nesting depths using original coordinates
2. Apply x offsets

Files changed:

• src/svg/buildGeometry.ts — two-pass nesting computation
• src/svg/buildGeometry.spec.ts — new test verifying 3 nested fragments get distinct x positions (-30, -20, -10)

No regressions.