make trpc-nuxt flexible by exporting server and client functions instead of nuxt modules

src/server.ts

@@ -0,0 +1,90 @@
+import type { ResponseMeta } from '@trpc/server/http'
+import { resolveHTTPResponse } from '@trpc/server/http'
+import type {
+  AnyRouter,
+  ProcedureType,
+  TRPCError,
+  inferRouterContext,
+  inferRouterError,
+} from '@trpc/server'
+import { createURL } from 'ufo'
+import type { H3Event } from 'h3'
+import { defineEventHandler, isMethod, readBody } from 'h3'
+import type { TRPCResponse } from '@trpc/server/rpc'
+
+type MaybePromise<T> = T | Promise<T>
+
+export type CreateContextFn<TRouter extends AnyRouter> = (event: H3Event) => MaybePromise<inferRouterContext<TRouter>>
+
+export interface ResponseMetaFnPayload<TRouter extends AnyRouter> {
+  data: TRPCResponse<unknown, inferRouterError<TRouter>>[]
+  ctx?: inferRouterContext<TRouter>
+  paths?: string[]
+  type: ProcedureType | 'unknown'
+  errors: TRPCError[]
+}
+
+export type ResponseMetaFn<TRouter extends AnyRouter> = (opts: ResponseMetaFnPayload<TRouter>) => ResponseMeta
+
+export interface OnErrorPayload<TRouter extends AnyRouter> {
+  error: TRPCError
+  type: ProcedureType | 'unknown'
+  path: string | undefined
+  req: H3Event['req']
+  input: unknown
+  ctx: undefined | inferRouterContext<TRouter>
+}
+
+export type OnErrorFn<TRouter extends AnyRouter> = (opts: OnErrorPayload<TRouter>) => void
+
+export function createNuxtApiHandler<TRouter extends AnyRouter>({
+  router,
+  createContext,
+  responseMeta,
+  onError,
+  url = '/api/trpc',
+}: {
+  router: TRouter
+  createContext?: CreateContextFn<TRouter>
+  responseMeta?: ResponseMetaFn<TRouter>
+  onError?: OnErrorFn<TRouter>
+  url?: string
+}) {
+  return defineEventHandler(async (event) => {
+    const {
+      req,
+      res,
+    } = event
+
+    const $url = createURL(req.url!)
+
+    const httpResponse = await resolveHTTPResponse({
+      router,
+      req: {
+        method: req.method!,
+        headers: req.headers,
+        body: isMethod(event, 'GET') ? null : await readBody(event),
+        query: $url.searchParams,
+      },
+      path: $url.pathname.substring(url.length + 1),
+      createContext: async () => createContext?.(event),
+      responseMeta,
+      onError: (o) => {
+        onError?.({
+          ...o,
+          req,
+        })
+      },
+    })
+
+    const { status, headers, body } = httpResponse
+
+    res.statusCode = status
+
+    headers && Object.keys(headers).forEach((key) => {
+      res.setHeader(key, headers[key]!)
+    })
+
+    return body
+  })
+}