Enable goConfig to infer its return type

By adding some extra typescript magic

app/auth/token/refresh/route.ts

@@ -16,7 +16,7 @@ const sessionTokenSchema = z.object({
 })
 
 export async function GET(request: NextRequest, response: NextResponse) {
-  const appUrl = goConfig<string>("app.url")
+  const appUrl = goConfig("app.url")
   const session = await getSession()
   const frontpage = `${appUrl}/`
 

app/page.tsx

@@ -2,7 +2,7 @@ import Image from "next/image"
 
 import goConfig from "@/lib/config/config"
 
-const wellknownUrl = goConfig<Promise<string | undefined>>("service.unilogin.wellknown.url")
+const wellknownUrl = goConfig("service.unilogin.wellknown.url")
 export default async function Home() {
   return (
     <div

codegen.ts

@@ -47,7 +47,7 @@ const config: CodegenConfig = {
       documents: "**/*.fbi.graphql",
       schema: [
         {
-          [goConfig<string>("service.fbi.graphql.endpoint")]: {
+          [String(goConfig("service.fbi.graphql.endpoint"))]: {
             headers: {
               Authorization: `Bearer ${goConfig("token.adgangsplatformen.library")}`,
             },

components/pages/searchPageLayout/helper.ts

@@ -4,7 +4,6 @@ import { ReadonlyURLSearchParams } from "next/navigation"
 
 import { getFacetMachineNames } from "@/components/shared/searchFilters/helper"
 import goConfig from "@/lib/config/config"
-import { TConfigSearchFacets } from "@/lib/config/resolvers/search"
 import { SearchFiltersInput, SearchWithPaginationQuery } from "@/lib/graphql/generated/fbi/graphql"
 import { TFilters } from "@/lib/machines/search/types"
 import useSearchMachineActor from "@/lib/machines/search/useSearchMachineActor"
@@ -18,29 +17,29 @@ export const getSearchQueryArguments = ({
   currentPage: number
   facetFilters: SearchFiltersInput
 }) => {
-  const limit = goConfig<number>("search.item.limit")
+  const limit = goConfig("search.item.limit")
   return {
     q: { all: q },
     offset: currentPage * limit,
     limit: limit,
     filters: {
-      branchId: goConfig<`${number}`[]>("search.branch.ids"),
+      branchId: goConfig("search.branch.ids"),
       ...facetFilters,
     },
   }
 }
 
 export const getFacetsForSearchRequest = (searchParams: ReadonlyURLSearchParams) => {
-  const facets = goConfig<TConfigSearchFacets>("search.facets")
+  const facets = goConfig("search.facets")
   const facetsMachineNames = getFacetMachineNames()
 
   return facetsMachineNames.reduce(
     (acc: TFilters, machineName) => {
-      const values = searchParams.getAll(facets[machineName].filter)
+      const values = searchParams.getAll(facets[machineName as keyof typeof facets].filter)
       if (values.length > 0) {
         return {
           ...acc,
-          [facets[machineName].filter]: [...values],
+          [facets[machineName as keyof typeof facets].filter]: [...values],
         }
       }
       return acc
@@ -52,7 +51,7 @@ export const getFacetsForSearchRequest = (searchParams: ReadonlyURLSearchParams)
 export const getNextPageParamsFunc = (
   currentPage: number
 ): GetNextPageParamFunction<number, SearchWithPaginationQuery> => {
-  const limit = goConfig<number>("search.item.limit")
+  const limit = goConfig("search.item.limit")
 
   return ({ search: { hitcount } }) => {
     const totalPages = Math.ceil(hitcount / limit)

components/shared/searchFilters/helper.ts

@@ -3,7 +3,6 @@ import { AppRouterInstance } from "next/dist/shared/lib/app-router-context.share
 import { ReadonlyURLSearchParams } from "next/navigation"
 
 import goConfig from "@/lib/config/config"
-import { TConfigSearchFacets } from "@/lib/config/resolvers/search"
 import { FacetFieldEnum, SearchFacetFragment } from "@/lib/graphql/generated/fbi/graphql"
 import { TContext, TFilters } from "@/lib/machines/search/types"
 
@@ -44,14 +43,14 @@ export const sortByActiveFacets = (facet: SearchFacetFragment, selectedFilters:
 }
 
 export const getFacetMachineNames = () => {
-  const facets = goConfig<Record<string, unknown>>("search.facets")
+  const facets = goConfig("search.facets")
   return Object.keys(facets) as FacetFieldEnum[]
 }
 
 export const getFacetTranslation = (facetFilter: keyof TFilters) => {
-  const facets = goConfig<TConfigSearchFacets>("search.facets")
+  const facets = goConfig("search.facets")
 
-  return facets[facetFilter.toUpperCase() as keyof TConfigSearchFacets].translation || ""
+  return facets[facetFilter.toUpperCase() as keyof typeof facets].translation || ""
 }
 
 export const getActiveFilters = (

lib/config/config.ts

@@ -13,7 +13,10 @@ const resolvers = {
   ...token,
 }
 
-const retrieveValue = (key: keyof typeof resolvers) => {
+type TResolvers = typeof resolvers
+type TConfigKey = keyof TResolvers
+
+const retrieveValue = (key: TConfigKey): any => {
   if (key in resolvers) {
     if (typeof resolvers[key] !== "function") {
       return resolvers[key]
@@ -24,8 +27,10 @@ const retrieveValue = (key: keyof typeof resolvers) => {
   return null
 }
 
-const goConfig = <TValue>(key: keyof typeof resolvers) => {
-  const value = retrieveValue(key) as TValue
+const goConfig = <K extends TConfigKey>(
+  key: K
+): TResolvers[K] extends () => infer R ? R : TResolvers[K] => {
+  const value = retrieveValue(key)
 
   if (!value && value !== 0) {
     throw new MissingConfigurationError(`Missing configuration for ${key}`)

lib/config/resolvers/app.ts

@@ -11,6 +11,7 @@ const app = {
         }
       }
     }
+    throw new Error("No app URL found.")
   },
 }
 

lib/config/resolvers/search.ts

@@ -51,6 +51,4 @@ const search = {
   },
 }
 
-export type TConfigSearchFacets = Record<FacetFieldEnum, { filter: string; translation: string }>
-
 export default search

lib/config/resolvers/service.unilogin.ts

@@ -37,6 +37,7 @@ const serviceUnilogin = {
     if (process.env.UNILOGIN_SESSION_SECRET) {
       return process.env.UNILOGIN_SESSION_SECRET
     }
+    throw new Error("No unilogin session secret found.")
   },
 }
 

lib/machines/search/useSearchMachineActor.tsx

@@ -14,9 +14,9 @@ import searchMachine from "./search.machine"
 
 const searchActor = createActor(searchMachine, {
   input: {
-    initialOffset: goConfig<number>("search.offset.initial"),
-    searchPageSize: goConfig<number>("search.item.limit"),
-    facetLimit: goConfig<number>("search.facet.limit"),
+    initialOffset: goConfig("search.offset.initial"),
+    searchPageSize: goConfig("search.item.limit"),
+    facetLimit: goConfig("search.facet.limit"),
   },
 }).start()
 

lib/session/oauth/uniloginClient.ts

@@ -3,15 +3,15 @@ import { Issuer } from "openid-client"
 import goConfig from "@/lib/config/config"
 
 export const getOpenIdClientUniloginClientConfig = async () => {
-  const appUrl = await goConfig<Promise<string | undefined>>("app.url")
-  const apiUrl = await goConfig<Promise<string | undefined>>("service.unilogin.api.url")
+  const appUrl = goConfig("app.url")
+  const apiUrl = await goConfig("service.unilogin.api.url")
 
   return {
-    wellKnownUrl: await goConfig<Promise<string | undefined>>("service.unilogin.wellknown.url"),
+    wellKnownUrl: await goConfig("service.unilogin.wellknown.url"),
     url: apiUrl,
     audience: apiUrl,
-    client_id: await goConfig<Promise<string | undefined>>("service.unilogin.client-id"),
-    client_secret: await goConfig<Promise<string | undefined>>("service.unilogin.client-secret"),
+    client_id: await goConfig("service.unilogin.client-id"),
+    client_secret: await goConfig("service.unilogin.client-secret"),
     scope: "openid",
     redirect_uri: `${appUrl}/auth/callback/unilogin`,
     post_logout_redirect_uri: appUrl,