refactor: rename internal type

README.md

@@ -224,7 +224,7 @@ To do that, pass a function that returns the headers to the `headers` property w
 import { GraphQLClient } from 'graphql-request'
 
 const client = new GraphQLClient(endpoint, {
-  headers: () => ({ 'X-Sent-At-Time': Date.now() }),
+  headers: () => ({ 'X-Sent-At-Time': Date.now().toString() }),
 })
 
 const query = gql`

src/index.ts

@@ -15,7 +15,7 @@ import type {
   GraphQLClientResponse,
   HTTPMethodInput,
   JsonSerializer,
-  MaybeFunction,
+  MaybeLazy,
   RequestConfig,
   RequestMiddleware,
   VariablesAndRequestHeadersArgs,
@@ -628,7 +628,7 @@ const getResult = async (
   }
 }
 
-const callOrIdentity = <T>(value: MaybeFunction<T>) => {
+const callOrIdentity = <T>(value: MaybeLazy<T>) => {
   return typeof value === `function` ? (value as () => T)() : value
 }
 

src/types.ts

@@ -77,7 +77,7 @@ export class ClientError extends Error {
   }
 }
 
-export type MaybeFunction<T> = T | (() => T)
+export type MaybeLazy<T> = T | (() => T)
 
 export type RequestDocument = string | DocumentNode
 
@@ -94,7 +94,7 @@ export type HTTPMethodInput = 'GET' | 'POST' | 'get' | 'post'
 export interface RequestConfig extends Omit<RequestInit, 'headers' | 'method'>, AdditionalRequestOptions {
   fetch?: Fetch
   method?: HTTPMethodInput
-  headers?: MaybeFunction<GraphQLClientRequestHeaders>
+  headers?: MaybeLazy<GraphQLClientRequestHeaders>
   requestMiddleware?: RequestMiddleware
   responseMiddleware?: (response: GraphQLClientResponse<unknown> | Error) => void
   jsonSerializer?: JsonSerializer