fix: Better type narrowing in calculationSchema

theopensystemslab · Aug 2, 2024 · 8148158 · 8148158
1 parent 05f038c
commit 8148158
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/app/schemas/calculationSchema.ts b/app/schemas/calculationSchema.ts
@@ -12,7 +12,10 @@ export const calculationSchema = z.object({
     .min(1, "housePostcode is required")
     .refine(fixPostcode, "Invalid postcode")
     .transform(parsePostcode)
-    .refine((postcode) => postcode.valid, { message: "Invalid postcode" }),
+    .refine(
+      (postcode): postcode is Extract<ReturnType<typeof parsePostcode>, { valid: true }> =>
+        postcode.valid,
+    ),
   houseSize: z.coerce.number().positive("houseSize must be a positive integer"),
   houseAge: z.coerce.number().positive("houseAge must be a positive integer"),
   houseBedrooms: z.coerce