u

generate-schema-graph.js

@@ -711,6 +711,61 @@ function countSvgCrossings(svg) {
   return n;
 }
 
+/**
+ * Graphviz self-edges from a lower FK row to id:e dip southeast. Rebuild the
+ * spline so it bulges east + north (up) while keeping start/end ports.
+ * In this SVG, more-negative y is visually higher.
+ */
+function fixSelfLoopSvg(svg) {
+  return svg.replace(
+    /<g id="(edge\d+)" class="edge">\s*<title>(\w+):e&#45;&gt;\2:e<\/title>\s*<g id="(a_edge\d+)"><a ([^>]+)>\s*<path([^>]*) d="([^"]+)"\/>\s*<polygon([^>]*) points="([^"]+)"\/>\s*<\/a>\s*<\/g>\s*<\/g>/g,
+    (match, edgeId, _table, aId, aAttrs, pathAttrs, d, polyAttrs) => {
+      const pts = [...d.matchAll(/([-\d.]+)[,\s]+([-\d.]+)/g)].map((m) => [
+        Number(m[1]),
+        Number(m[2]),
+      ]);
+      if (pts.length < 2) return match;
+
+      const [x0, y0] = pts[0];
+      const [x1, y1] = pts[pts.length - 1];
+      const east = Math.max(x0, x1) + 36;
+      const north = Math.min(y0, y1) - 28;
+
+      // Cubic end tangent is P3-P2; orient arrow along that arrival direction.
+      const tx = x1 - east;
+      const ty = y1 - north;
+      const len = Math.hypot(tx, ty) || 1;
+      const dx = tx / len;
+      const dy = ty / len;
+      const arrowLen = 9;
+      const arrowHalf = 3.5;
+      const baseX = x1 - dx * arrowLen;
+      const baseY = y1 - dy * arrowLen;
+      const px = -dy * arrowHalf;
+      const py = dx * arrowHalf;
+
+      const fmt = (n) => (Math.round(n * 100) / 100).toString();
+      const newDFmt = `M${fmt(x0)},${fmt(y0)}C${fmt(east)},${fmt(y0)} ${fmt(east)},${fmt(north)} ${fmt(baseX)},${fmt(baseY)}`;
+      const newPointsFmt =
+        `${fmt(x1)},${fmt(y1)} ` +
+        `${fmt(baseX + px)},${fmt(baseY + py)} ` +
+        `${fmt(baseX - px)},${fmt(baseY - py)} ` +
+        `${fmt(x1)},${fmt(y1)}`;
+
+      return (
+        `<g id="${edgeId}" class="edge">\n` +
+        `<title>${_table}:e&#45;&gt;${_table}:e</title>\n` +
+        `<g id="${aId}"><a ${aAttrs}>\n` +
+        `<path${pathAttrs} d="${newDFmt}"/>\n` +
+        `<polygon${polyAttrs} points="${newPointsFmt}"/>\n` +
+        `</a>\n` +
+        `</g>\n` +
+        `</g>`
+      );
+    }
+  );
+}
+
 const schemaSource = readFileSync(schemaPath, 'utf8');
 const { tables, edges } = parseSchema(schemaSource);
 
@@ -742,7 +797,7 @@ for (let pass = 0; pass < 2; pass++) {
 const dot = buildDot(tables, edges, positions);
 writeFileSync(dotOutputPath, dot, 'utf8');
 
-const svg = graphviz.layout(dot, 'svg', 'dot');
+const svg = fixSelfLoopSvg(graphviz.layout(dot, 'svg', 'dot'));
 writeFileSync(outputPath, svg, 'utf8');
 
 const dim = svg.match(/width="([\d.]+)pt" height="([\d.]+)pt"/);