From 383ab74dfa1650a2b5a8b8ecf5a30328166030d8 Mon Sep 17 00:00:00 2001
From: adityaaa-IIT-BHU <aditya.acharya.bme23@itbhu.ac.in>
Date: Tue, 4 Aug 2026 10:44:45 +0900
Subject: [PATCH] fix: key fuse connections on pin labels (#754)
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fuseProps built its connections schema by hand with z.record(z.string(),
...), so any key passed validation — pin99, "not a pin at all", even "".
Every other two-pin passive builds it from its own pin labels via
createConnectionsProp, which keys the record on z.enum(labels).

Use createConnectionsProp(fusePinLabels), and narrow the interface to
Connections<FusePinLabels> to match capacitor and resistor.

Fuse was also the only component in lib/components/ exporting both an
interface and an Inferred* type without calling expectTypesMatch, which
is why the schema and FuseProps were able to drift apart. Add the
assertion so it can't happen again.
---
 README.md                    |  2 +-
 generated/COMPONENT_TYPES.md | 13 ++--------
 generated/PROPS_OVERVIEW.md  |  2 +-
 lib/components/fuse.ts       | 17 +++++--------
 tests/fuse.test.ts           | 48 ++++++++++++++++++++++++++++++++++++
 5 files changed, 58 insertions(+), 24 deletions(-)
 create mode 100644 tests/fuse.test.ts

diff --git a/README.md b/README.md
index 6236788e..242c5149 100644
--- a/README.md
+++ b/README.md
@@ -941,7 +941,7 @@ export interface FuseProps<
   /**
    * Connections to other components
    */
-  connections?: Connections<PinLabel>;
+  connections?: Connections<FusePinLabels>;
 }
 ```
 
diff --git a/generated/COMPONENT_TYPES.md b/generated/COMPONENT_TYPES.md
index 58a0e324..00211f8a 100644
--- a/generated/COMPONENT_TYPES.md
+++ b/generated/COMPONENT_TYPES.md
@@ -2155,7 +2155,7 @@ export interface FuseProps<PinLabel extends string = string>
 
   schOrientation?: SchematicOrientation
 
-  connections?: Connections<PinLabel>
+  connections?: Connections<FusePinLabels>
 }
 /**
  * Schema for validating fuse props
@@ -2165,16 +2165,7 @@ 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(),
 })
 ```
 
diff --git a/generated/PROPS_OVERVIEW.md b/generated/PROPS_OVERVIEW.md
index cfdfde4a..45d09789 100644
--- a/generated/PROPS_OVERVIEW.md
+++ b/generated/PROPS_OVERVIEW.md
@@ -1119,7 +1119,7 @@ export interface FuseProps<PinLabel extends string = string>
   /**
    * Connections to other components
    */
-  connections?: Connections<PinLabel>
+  connections?: Connections<FusePinLabels>
 }
 
 
diff --git a/lib/components/fuse.ts b/lib/components/fuse.ts
index 1a4798b8..86797407 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,
@@ -7,6 +8,7 @@ import {
   schematicOrientation,
   type SchematicOrientation,
 } from "lib/common/schematicOrientation"
+import { expectTypesMatch } from "lib/typecheck"
 import type { Connections } from "lib/utility-types/connections-and-selectors"
 
 /**
@@ -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.test.ts b/tests/fuse.test.ts
new file mode 100644
index 00000000..7703bb7d
--- /dev/null
+++ b/tests/fuse.test.ts
@@ -0,0 +1,48 @@
+import { expect, test } from "bun:test"
+import { fuseProps, type FuseProps } from "lib/components/fuse"
+
+test("should parse fuse connections keyed by pin labels", () => {
+  const raw: FuseProps = {
+    name: "F1",
+    currentRating: "1A",
+    connections: {
+      pin1: "net.VCC",
+      pin2: ["net.GND"],
+    },
+  }
+
+  const parsed = fuseProps.parse(raw)
+  expect(parsed.connections).toEqual({
+    pin1: "net.VCC",
+    pin2: ["net.GND"],
+  })
+})
+
+test("should reject fuse connections keyed by an unknown pin", () => {
+  const parsed = fuseProps.safeParse({
+    name: "F1",
+    currentRating: "1A",
+    connections: { pin99: ".R1 > .pin1" },
+  })
+
+  expect(parsed.success).toBe(false)
+})
+
+test("should reject fuse connections keyed by an empty string", () => {
+  const parsed = fuseProps.safeParse({
+    name: "F1",
+    currentRating: "1A",
+    connections: { "": ".R1 > .pin1" },
+  })
+
+  expect(parsed.success).toBe(false)
+})
+
+test("should allow optional fuse connections", () => {
+  const parsed = fuseProps.parse({
+    name: "F1",
+    currentRating: "1A",
+  })
+
+  expect(parsed.connections).toBeUndefined()
+})