fix: support jst_ph_N format and dynamic PH silkscreen sizing

src/fn/jst.ts

@@ -150,17 +150,20 @@ function generateSilkscreenBody(
   numPins?: number,
   p?: number,
 ): PcbSilkscreenPath {
-  if (variant === "ph") {
+  if (variant === "ph" && numPins && p) {
+    const pinSpan = (numPins - 1) * p
+    const bodyLeft = -pinSpan / 2 - 1.5
+    const bodyRight = pinSpan / 2 + 1.5
     return {
       type: "pcb_silkscreen_path",
       layer: "top",
       pcb_component_id: "",
       route: [
-        { x: -3, y: 3 },
-        { x: 3, y: 3 },
-        { x: 3, y: -2 },
-        { x: -3, y: -2 },
-        { x: -3, y: 3 },
+        { x: bodyLeft, y: 3 },
+        { x: bodyRight, y: 3 },
+        { x: bodyRight, y: -2 },
+        { x: bodyLeft, y: -2 },
+        { x: bodyLeft, y: 3 },
       ],
       stroke_width: 0.1,
       pcb_silkscreen_path_id: "",
@@ -222,6 +225,8 @@ export const jst = (
   const str = typeof raw_params.string === "string" ? raw_params.string : ""
   const match = str.match(/(?:^|_)jst(\d+)(?:_|$)/)
   const zhMatch = str.match(/(?:^|_)zh(\d+)(?:_|$)/)
+  // Match trailing pin count after variant, e.g. jst_ph_4, jst_sh_6
+  const trailingMatch = str.match(/(?:^|_)(\d+)(?:_|$)/)
   if (match && match[1]) {
     const parsed = Number.parseInt(match[1], 10)
     if (!Number.isNaN(parsed)) {
@@ -234,6 +239,12 @@ export const jst = (
       numPins = parsed
     }
   }
+  if (typeof numPins !== "number" && trailingMatch && trailingMatch[1]) {
+    const parsed = Number.parseInt(trailingMatch[1], 10)
+    if (!Number.isNaN(parsed)) {
+      numPins = parsed
+    }
+  }
 
   if (typeof numPins !== "number") {
     throw new Error(

tests/jst_ph_4.test.ts

@@ -0,0 +1,13 @@
+import { expect, test } from "bun:test"
+import { convertCircuitJsonToPcbSvg } from "circuit-to-svg"
+import { fp } from "../src/footprinter"
+
+test("jst_ph_4 generates 4 pads", () => {
+  const circuitJson = fp.string("jst_ph_4").circuitJson()
+
+  const platedHoles = circuitJson.filter((e) => e.type === "pcb_plated_hole")
+  expect(platedHoles.length).toBe(4)
+
+  const svgContent = convertCircuitJsonToPcbSvg(circuitJson)
+  expect(svgContent).toMatchSvgSnapshot(import.meta.path)
+})