Discriminated union handle

How Do I handle Input type if its discriminated union??

export const batchTasksRouter = createTRPCRouter({
  requestExport: procedure
    .input(
      z.discriminatedUnion('type', [
        z.object({
          type: ExportsZSchema,
        }),
        z.object({
          type: ExportsZSchema,
          id: z.string().uuid(),
        }),
        z.object({
          type: ExportsZSchema,
          id: z.string().uuid(),
          query: z.object({
            from: z.string(),
            to: z.string(),
            type: z.string().optional(),
          }),
        }),
      ]),
    )
    .query(async ({ ctx, input }) => {
      const { id, query, type } = input // <------- TYPESCRIPT ERRRORS that id and query not exists
      let urlSuffix = type

      if (id) urlSuffix += `/${id}`

      if (query) urlSuffix += `?${querystring.stringify(query)}`
...
    }),
})

export const batchTasksRouter = createTRPCRouter({
  requestExport: procedure
    .input(
      z.discriminatedUnion('type', [
        z.object({
          type: ExportsZSchema,
        }),
        z.object({
          type: ExportsZSchema,
          id: z.string().uuid(),
        }),
        z.object({
          type: ExportsZSchema,
          id: z.string().uuid(),
          query: z.object({
            from: z.string(),
            to: z.string(),
            type: z.string().optional(),
          }),
        }),
      ]),
    )
    .query(async ({ ctx, input }) => {
      const { id, query, type } = input // <------- TYPESCRIPT ERRRORS that id and query not exists
      let urlSuffix = type

      if (id) urlSuffix += `/${id}`

      if (query) urlSuffix += `?${querystring.stringify(query)}`
...
    }),
})

TS2339: Property 'id' does not exist on type ... TS2339: Property 'query' does not exist on type ...

4 Replies

Nick•2y ago

Same way as normal in typescript

Nick•2y ago

https://www.typescriptlang.org/docs/handbook/2/narrowing.html#discriminated-unions

Documentation - Narrowing

Understand how TypeScript uses JavaScript knowledge to reduce the amount of type syntax in your projects.

Nick•2y ago

Type also needs to be a z.literal, not sure what you're doing there

Mugetsu•2y ago

Thx got it.