Fix stub edges on schematic traces

lib/components/primitive-components/Trace.ts

@@ -31,6 +31,9 @@ import { PrimitiveComponent } from "../base-components/PrimitiveComponent"
 import type { Net } from "./Net"
 import type { Port } from "./Port"
 import type { TraceHint } from "./TraceHint"
+import { getDominantDirection } from "lib/utils/autorouting/getDominantDirection"
+import type { Point } from "@tscircuit/math-utils"
+import { getStubEdges } from "lib/utils/schematic/getStubEdges"
 
 type PcbRouteObjective =
   | RouteHintPoint
@@ -672,6 +675,17 @@ export class Trace extends PrimitiveComponent<typeof traceProps> {
       })
     }
 
+    // The last edges sometimes don't connect to the ports because the
+    // autorouter is within the "goal box" and doesn't finish the route
+    // Add a stub to connect the last point to the end port
+    const lastEdge = edges[edges.length - 1]
+    const lastEdgePort = portsWithPosition[portsWithPosition.length - 1]
+    const lastDominantDirection = getDominantDirection(lastEdge)
+    // Add the connecting edges
+    edges.push(
+      ...getStubEdges({ lastEdge, lastEdgePort, lastDominantDirection }),
+    )
+
     const trace = db.schematic_trace.insert({
       source_trace_id: this.source_trace_id!,
       edges,

lib/utils/autorouting/getDominantDirection.ts

@@ -0,0 +1,23 @@
+import type { Point } from "@tscircuit/math-utils"
+
+export function getDominantDirection(edge: {
+  from: Point
+  to: Point
+}): "right" | "left" | "up" | "down" {
+  const delta = {
+    x: edge.to.x - edge.from.x,
+    y: edge.to.y - edge.from.y,
+  }
+
+  // Use absolute values to compare magnitude of x and y movement
+  const absX = Math.abs(delta.x)
+  const absY = Math.abs(delta.y)
+
+  // If horizontal movement is greater than vertical
+  if (absX > absY) {
+    return delta.x > 0 ? "right" : "left"
+  }
+
+  // If vertical movement is greater than or equal to horizontal
+  return delta.y > 0 ? "down" : "up"
+}

lib/utils/schematic/getStubEdges.ts

@@ -0,0 +1,53 @@
+import type { Point } from "@tscircuit/math-utils"
+
+type Edge = {
+  from: Point
+  to: Point
+}
+
+export const getStubEdges = ({
+  lastEdge,
+  lastEdgePort,
+  lastDominantDirection,
+}: {
+  lastEdge: Edge
+  lastEdgePort: { position: Point }
+  lastDominantDirection: "left" | "right" | "up" | "down"
+}) => {
+  const edges: Edge[] = []
+  if (lastEdge && lastEdgePort) {
+    const intermediatePoint = { x: lastEdge.to.x, y: lastEdge.to.y }
+
+    // If the last movement was horizontal (left/right)
+    if (lastDominantDirection === "left" || lastDominantDirection === "right") {
+      // First continue horizontally to align with port's x-position
+      intermediatePoint.x = lastEdgePort.position.x
+      edges.push({
+        from: lastEdge.to,
+        to: { ...intermediatePoint },
+      })
+
+      // Then move vertically to reach port's y-position
+      edges.push({
+        from: intermediatePoint,
+        to: { ...lastEdgePort.position },
+      })
+    }
+    // If the last movement was vertical (up/down)
+    else {
+      // First continue vertically to align with port's y-position
+      intermediatePoint.y = lastEdgePort.position.y
+      edges.push({
+        from: lastEdge.to,
+        to: { ...intermediatePoint },
+      })
+
+      // Then move horizontally to reach port's x-position
+      edges.push({
+        from: intermediatePoint,
+        to: { ...lastEdgePort.position },
+      })
+    }
+  }
+  return edges
+}