support for most of the append_to_response options

src/endpoints/movies.ts

@@ -1,6 +1,8 @@
 import { BaseEndpoint } from './base';
 import {
   AlternativeTitles,
+  AppendToResponse,
+  AppendToResponseKeys,
   ChangeOptions,
   Credits,
   ExternalIds,
@@ -33,8 +35,18 @@ export class MoviesEndpoint extends BaseEndpoint {
     super(accessToken);
   }
 
-  async details(id: number): Promise<MovieDetails> {
-    return await this.api.get<MovieDetails>(`${BASE_MOVIE}/${id}`);
+  async details<T extends AppendToResponseKeys[]>(
+    id: number,
+    appendToResponse?: T
+  ) {
+    const options = {
+      append_to_response: appendToResponse ? appendToResponse.join(',') : undefined,
+    };
+
+    return await this.api.get<AppendToResponse<MovieDetails, T>>(
+      `${BASE_MOVIE}/${id}`,
+      options
+    );
   }
 
   async alternativeTitles(id: number): Promise<AlternativeTitles> {

src/endpoints/tv-shows.ts

@@ -1,6 +1,8 @@
 import { BaseEndpoint } from './base';
 import {
   AlternativeTitles,
+  AppendToResponse,
+  AppendToResponseKeys,
   ChangeOptions,
   ContentRatings,
   Credits,
@@ -35,8 +37,19 @@ export class TvShowsEndpoint extends BaseEndpoint {
     super(accessToken);
   }
 
-  async details(id: number): Promise<TvShowDetails> {
-    return await this.api.get<TvShowDetails>(`${BASE_TV}/${id}`);
+  async details<T extends AppendToResponseKeys[]>(
+    id: number,
+    appendToResponse?: T
+  ) {
+    const options = {
+      append_to_response: appendToResponse
+        ? appendToResponse.join(',')
+        : undefined,
+    };
+    return await this.api.get<AppendToResponse<TvShowDetails, T>>(
+      `${BASE_TV}/${id}`,
+      options
+    );
   }
 
   async alternativeTitles(id: number): Promise<AlternativeTitles> {

src/types/options.ts

@@ -1,3 +1,13 @@
+import {
+  Credits,
+  Images,
+  Keywords,
+  Recommendations,
+  Reviews,
+  Translations,
+  Videos,
+} from '.';
+
 export interface LanguageOption {
   language?: string;
 }
@@ -9,3 +19,31 @@ export interface RegionOption {
 export interface PageOption {
   page?: number;
 }
+
+export type AppendToResponseKeys =
+  | 'images'
+  | 'videos'
+  | 'credits'
+  | 'recommendations'
+  | 'reviews'
+  | 'keywords';
+
+export type AppendToResponse<
+  K,
+  T extends AppendToResponseKeys[] | undefined
+> = K &
+  (T extends undefined
+    ? object
+    : T extends Array<unknown>
+    ? ('credits' extends T[number] ? { credits: Omit<Credits, 'id'> } : object) &
+        ('videos' extends T[number] ? { videos: Omit<Videos, 'id'> } : object) &
+        ('images' extends T[number] ? { images: Omit<Images, 'id'> } : object) &
+        ('recommendations' extends T[number]
+          ? { recommendations: Recommendations }
+          : object) &
+        ('reviews' extends T[number] ? { reviews: Omit<Reviews, 'id'> } : object) &
+        ('reviews' extends T[number]
+          ? { reviews: Omit<Translations, 'id'> }
+          : object) &
+        ('keywords' extends T[number] ? { keywords: Omit<Keywords, 'id'> } : object)
+    : never);