Function dehydrateQuery

packages/query-core/src/hydration.ts:78–123

(
  query: Query,
  serializeData: TransformerFn,
  shouldRedactErrors: (error: unknown) => boolean,
)

// Sometimes it might make sense to prefetch data on the server and include
// in the html-payload, but not consume it on the initial render.
function dehydrateQuery(
  query: Query,
  serializeData: TransformerFn,
  shouldRedactErrors: (error: unknown) => boolean,
): DehydratedQuery {
  const dehydratePromise = () => {
    const promise = query.promise?.then(serializeData).catch((error) => {
      if (!shouldRedactErrors(error)) {
        // Reject original error if it should not be redacted
        return Promise.reject(error)
      }
      // If not in production, log original error before rejecting redacted error
      if (process.env.NODE_ENV !== 'production') {
        console.error(
          `A query that was dehydrated as pending ended up rejecting. [${query.queryHash}]: ${error}; The error will be redacted in production builds`,
        )
      }
      return Promise.reject(new Error('redacted'))
    })

    // Avoid unhandled promise rejections
    // We need the promise we dehydrate to reject to get the correct result into
    // the query cache, but we also want to avoid unhandled promise rejections
    // in whatever environment the prefetches are happening in.
    promise?.catch(noop)

    return promise
  }

  return {
    dehydratedAt: Date.now(),
    state: {
      ...query.state,
      ...(query.state.data !== undefined && {
        data: serializeData(query.state.data),
      }),
    },
    queryKey: query.queryKey,
    queryHash: query.queryHash,
    ...(query.state.status === 'pending' && {
      promise: dehydratePromise(),
    }),
    ...(query.meta && { meta: query.meta }),
    ...(query.queryType && { queryType: query.queryType }),
  }
}

export function defaultShouldDehydrateMutation(mutation: Mutation) {
  return mutation.state.isPaused