Function executeMiddleware

packages/start-client-core/src/createServerFn.ts:228–369

(
  middlewares: Array<AnyFunctionMiddleware | AnyRequestMiddleware>,
  env: 'client' | 'server',
  opts: ServerFnMiddlewareOptions,
)

}

export async function executeMiddleware(
  middlewares: Array<AnyFunctionMiddleware | AnyRequestMiddleware>,
  env: 'client' | 'server',
  opts: ServerFnMiddlewareOptions,
): Promise<ServerFnMiddlewareResult> {
  const globalMiddlewares = getStartOptions()?.functionMiddleware || []
  let flattenedMiddlewares = flattenMiddlewares([
    ...globalMiddlewares,
    ...middlewares,
  ])

  // On server, filter out middlewares that already executed in the request phase
  // to prevent duplicate execution (issue #5239)
  if (env === 'server') {
    const startContext = getStartContextServerOnly({ throwIfNotFound: false })
    if (startContext?.executedRequestMiddlewares) {
      flattenedMiddlewares = flattenedMiddlewares.filter(
        (m) => !startContext.executedRequestMiddlewares.has(m),
      )
    }
  }

  const callNextMiddleware: NextFn = async (ctx) => {
    // Get the next middleware
    const nextMiddleware = flattenedMiddlewares.shift()

    // If there are no more middlewares, return the context
    if (!nextMiddleware) {
      return ctx
    }

    // Execute the middleware
    try {
      let validator =
        'validator' in nextMiddleware.options
          ? nextMiddleware.options.validator
          : undefined

      // TODO remove upon stable
      if (!validator && 'inputValidator' in nextMiddleware.options) {
        validator = nextMiddleware.options.inputValidator
      }

      if (validator && env === 'server') {
        // Execute the middleware's input function
        ctx.data = await execValidator(validator as AnyValidator, ctx.data)
      }

      let middlewareFn: MiddlewareFn | undefined = undefined
      if (env === 'client') {
        if ('client' in nextMiddleware.options) {
          middlewareFn = nextMiddleware.options.client as
            | MiddlewareFn
            | undefined
        }
      }
      // env === 'server'
      else if ('server' in nextMiddleware.options) {