Convert DIP inch and centimeter dimensions to millimeters

src/fn/dip.ts

@@ -4,6 +4,7 @@ import type {
   PcbFabricationNoteText,
   PcbSilkscreenPath,
 } from "circuit-json"
+import { length } from "circuit-json"
 import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
 import { base_def } from "../helpers/zod/base_def"
 
@@ -15,19 +16,13 @@ import { u_curve } from "../helpers/u-curve"
 import type { NowDefined } from "../helpers/zod/now-defined"
 import { createRectUnionOutline } from "src/helpers/rect-union-outline"
 
-function convertMilToMm(value: string | number): number {
-  if (typeof value === "string") {
-    if (value.trim().toLowerCase().endsWith("mil")) {
-      return parseFloat(value) * 0.0254
-    }
-    return parseFloat(value)
-  }
-  return Number(value)
-}
-
 const lengthInMm = z
   .union([z.string(), z.number()])
-  .transform((val) => convertMilToMm(val))
+  .transform((dimension) =>
+    length.parse(
+      typeof dimension === "string" ? dimension.toLowerCase() : dimension,
+    ),
+  )
 
 export const extendDipDef = (newDefaults: { w?: string; p?: string }) =>
   base_def
@@ -49,11 +44,11 @@ export const extendDipDef = (newDefaults: { w?: string; p?: string }) =>
     .transform((v) => {
       if (!v.id && !v.od) {
         if (Math.abs(v.p - 1.27) < 0.01) {
-          v.id = convertMilToMm("0.55mm")
-          v.od = convertMilToMm("0.95mm")
+          v.id = lengthInMm.parse("0.55mm")
+          v.od = lengthInMm.parse("0.95mm")
         } else {
-          v.id = convertMilToMm("0.8mm")
-          v.od = convertMilToMm("1.6mm")
+          v.id = lengthInMm.parse("0.8mm")
+          v.od = lengthInMm.parse("1.6mm")
         }
       } else if (!v.id) {
         v.id = v.od! * (1.0 / 1.5)
@@ -63,11 +58,11 @@ export const extendDipDef = (newDefaults: { w?: string; p?: string }) =>
 
       if (!v.w) {
         if (v.wide) {
-          v.w = convertMilToMm("600mil")
+          v.w = lengthInMm.parse("600mil")
         } else if (v.narrow) {
-          v.w = convertMilToMm("300mil")
+          v.w = lengthInMm.parse("300mil")
         } else {
-          v.w = convertMilToMm(newDefaults.w ?? "300mil")
+          v.w = lengthInMm.parse(newDefaults.w ?? "300mil")
         }
       }
       return v as NowDefined<typeof v, "w" | "p" | "id" | "od">

tests/dip-units.test.ts

@@ -0,0 +1,77 @@
+import { expect, test } from "bun:test"
+import { convertCircuitJsonToPcbSvg } from "circuit-to-svg"
+import { fp } from "../src/footprinter"
+import { dip_def } from "../src/fn/dip"
+
+test("DIP string and builder convert inch dimensions to millimeters", () => {
+  const circuitJson = fp
+    .string("dip4_w0.3in_p0.1in_id0.03in_od0.06in")
+    .circuitJson()
+  expect(circuitJson).toEqual(
+    fp().dip(4).w("0.3in").p("0.1in").id("0.03in").od("0.06in").circuitJson(),
+  )
+  const holes = circuitJson.filter(
+    (element) => element.type === "pcb_plated_hole",
+  )
+
+  expect(holes).toHaveLength(4)
+  const expectedCenters = [
+    { x: -3.81, y: 1.27 },
+    { x: -3.81, y: -1.27 },
+    { x: 3.81, y: -1.27 },
+    { x: 3.81, y: 1.27 },
+  ]
+  for (const [index, expectedCenter] of expectedCenters.entries()) {
+    expect(holes[index]?.x).toBeCloseTo(expectedCenter.x)
+    expect(holes[index]?.y).toBeCloseTo(expectedCenter.y)
+  }
+  const [pin1, pin2] = holes
+  if (
+    pin1?.shape !== "circular_hole_with_rect_pad" ||
+    pin2?.shape !== "circle"
+  ) {
+    throw new Error("Expected a rectangular pin 1 pad and a circular pin 2 pad")
+  }
+  expect(pin1.hole_diameter).toBeCloseTo(0.762)
+  expect(pin1.rect_pad_width).toBeCloseTo(1.524)
+  expect(pin1.rect_pad_height).toBeCloseTo(1.524)
+  expect(pin2.hole_diameter).toBeCloseTo(0.762)
+  expect(pin2.outer_diameter).toBeCloseTo(1.524)
+  expect(convertCircuitJsonToPcbSvg(circuitJson)).toMatchSvgSnapshot(
+    import.meta.path,
+    "dip-inch-dimensions",
+  )
+})
+
+test("DIP builder converts centimeter dimensions to millimeters", () => {
+  const circuitJson = fp()
+    .dip(4)
+    .w("0.762cm")
+    .p("0.254cm")
+    .id("0.08cm")
+    .od("0.16cm")
+    .circuitJson()
+
+  expect(circuitJson).toEqual(fp.string("dip4").circuitJson())
+  expect(convertCircuitJsonToPcbSvg(circuitJson)).toMatchSvgSnapshot(
+    import.meta.path,
+    "dip-centimeter-dimensions",
+  )
+})
+
+test.each([7.62, "7.62mm", "300mil", "300MIL", "300Mil", "0.3in", "0.762cm"])(
+  "DIP dimensions accept %s using the shared length conversion",
+  (dimension) => {
+    const parameters = dip_def.parse({
+      fn: "dip",
+      w: dimension,
+      p: dimension,
+      id: dimension,
+      od: dimension,
+    })
+
+    for (const dimensionName of ["w", "p", "id", "od"] as const) {
+      expect(parameters[dimensionName]).toBeCloseTo(7.62)
+    }
+  },
+)