From 3eed206d0e58f819049318ceb767beb053816c30 Mon Sep 17 00:00:00 2001
From: Jiho Lee <optional.int@kakao.com>
Date: Sun, 26 Jul 2026 06:08:30 +0900
Subject: [PATCH] fix: validate fuse connections against its pin labels (#754)

---
 lib/components/fuse.ts         | 17 +++++-------
 tests/fuse-connections.test.ts | 48 ++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 11 deletions(-)
 create mode 100644 tests/fuse-connections.test.ts

diff --git a/lib/components/fuse.ts b/lib/components/fuse.ts
index 1a4798b8..99ee34b3 100644
--- a/lib/components/fuse.ts
+++ b/lib/components/fuse.ts
@@ -1,4 +1,5 @@
 import { z } from "zod"
+import { createConnectionsProp } from "lib/common/connectionsProp"
 import {
   type CommonComponentProps,
   commonComponentProps,
@@ -8,6 +9,7 @@ import {
   type SchematicOrientation,
 } from "lib/common/schematicOrientation"
 import type { Connections } from "lib/utility-types/connections-and-selectors"
+import { expectTypesMatch } from "lib/typecheck"
 
 /**
  * Pin labels for fuse component
@@ -38,7 +40,7 @@ export interface FuseProps<PinLabel extends string = string>
   /**
    * Connections to other components
    */
-  connections?: Connections<PinLabel>
+  connections?: Connections<FusePinLabels>
 }
 
 /**
@@ -49,16 +51,9 @@ export const fuseProps = commonComponentProps.extend({
   voltageRating: z.union([z.number(), z.string()]).optional(),
   schShowRatings: z.boolean().optional(),
   schOrientation: schematicOrientation.optional(),
-  connections: z
-    .record(
-      z.string(),
-      z.union([
-        z.string(),
-        z.array(z.string()).readonly(),
-        z.array(z.string()),
-      ]),
-    )
-    .optional(),
+  connections: createConnectionsProp(fusePinLabels).optional(),
 })
 
 export type InferredFuseProps = z.input<typeof fuseProps>
+
+expectTypesMatch<FuseProps, InferredFuseProps>(true)
diff --git a/tests/fuse-connections.test.ts b/tests/fuse-connections.test.ts
new file mode 100644
index 00000000..168459a6
--- /dev/null
+++ b/tests/fuse-connections.test.ts
@@ -0,0 +1,48 @@
+import { expect, test } from "bun:test"
+import { capacitorProps } from "lib/components/capacitor"
+import { fuseProps } from "lib/components/fuse"
+
+const parseFuse = (connections: unknown) =>
+  fuseProps.safeParse({ name: "F1", currentRating: "1A", connections })
+
+test("fuse accepts its real pin labels in connections", () => {
+  expect(parseFuse({ pin1: ".R1 > .pin1" }).success).toBe(true)
+  expect(parseFuse({ pin2: ".R1 > .pin1" }).success).toBe(true)
+  expect(parseFuse({ pin1: ".R1 > .pin1", pin2: ".R2 > .pin1" }).success).toBe(
+    true,
+  )
+})
+
+test("fuse rejects a pin label it does not have", () => {
+  // Previously accepted: the schema used a bare z.record(z.string(), ...) so
+  // any key at all passed, including a typo'd pin that the fuse has no port for.
+  expect(parseFuse({ pin99: ".R1 > .pin1" }).success).toBe(false)
+  expect(parseFuse({ "not a pin at all": ".R1 > .pin1" }).success).toBe(false)
+  expect(parseFuse({ "": ".R1 > .pin1" }).success).toBe(false)
+})
+
+test("fuse validates connections the same way the other two-pin passives do", () => {
+  // Same typo, same shape of component — these must agree.
+  const typo = { pin99: ".R1 > .pin1" }
+
+  expect(parseFuse(typo).success).toBe(
+    capacitorProps.safeParse({
+      name: "C1",
+      capacitance: "1uF",
+      connections: typo,
+    }).success,
+  )
+})
+
+test("fuse still accepts array and readonly-array connection targets", () => {
+  expect(parseFuse({ pin1: [".R1 > .pin1", ".R2 > .pin1"] }).success).toBe(true)
+  expect(
+    parseFuse({ pin1: [".R1 > .pin1"] as readonly string[] }).success,
+  ).toBe(true)
+})
+
+test("connections stays optional on fuse", () => {
+  expect(fuseProps.safeParse({ name: "F1", currentRating: "1A" }).success).toBe(
+    true,
+  )
+})