Added tests for base64 image encoding

src/services/ImageService.ts

@@ -24,16 +24,20 @@ class ImageService {
         const validPosts = Promise.all(posts
             .filter(post => !imagesUrls.some(url => url === post.url))
             .map(async (post): Promise<Image> => {
-                const encodedImage = await this.imageUrlToBase64(post.url);
+                const imageData = await this.urlToImageData(post.url);
+                const encodedImage = this.imageToBase64(imageData);
                 return { url: post.url, tags: post.tags, content: encodedImage };
             }));
         
         return validPosts;
     }
 
-    private async imageUrlToBase64(url: string): Promise<string> {
-        const data = await (await fetch(url)).text();
-        return Buffer.from(data, "base64").toString("binary");
+    private async urlToImageData(url: string): Promise<string> {
+        return await (await fetch(url)).text();
+    }
+
+    private imageToBase64(imageData: string): string {
+        return Buffer.from(imageData, "binary").toString("base64");
     }
 }
 

test/ImageService/ImageService.test.ts

@@ -1,15 +1,16 @@
 import { describe, expect, it, mock, spyOn } from "bun:test";
-import Image from "../src/types/Image";
-import ImageService from "../src/services/ImageService";
-import GelbooruApiResponse from "../src/types/GelbooruServiceResponse";
-import { BotApiResponse } from "../src/types/BotApiResponse";
+import Image from "../../src/types/Image";
+import ImageService from "../../src/services/ImageService";
+import GelbooruApiResponse from "../../src/types/GelbooruServiceResponse";
+import { BotApiResponse } from "../../src/types/BotApiResponse";
+import fs from "node:fs";
 
 describe("endpoint gets a non repeated image", () => {
     it("should return an image that is not in the response of the /images endpoint of the bot API", async () => {
         const REPEATED_URL = "https://fastly.picsum.photos/id/1/10/20.jpg?hmac=gY6PvUXFacKfYpBpTTVcNLxumpyMmoCamM-J5DOPwNc";
         const UNIQUE_URL = "https://fastly.picsum.photos/id/2/10/20.jpg?hmac=zy6lz21CuRIstr9ETx9h5AuoH50s_L2uIEct3dROpY8";
 
-        mock.module("../src/services/GelbooruApiService", () => {
+        mock.module("../../src/services/GelbooruApiService", () => {
             let alreadyCalled = false;
             return {
                 default: {
@@ -25,7 +26,7 @@ describe("endpoint gets a non repeated image", () => {
             }
         });
 
-        mock.module("../src/services/BotApiService", () => ({
+        mock.module("../../src/services/BotApiService", () => ({
             default: {
                 getAll: (): BotApiResponse => ({
                     images: [
@@ -35,10 +36,19 @@ describe("endpoint gets a non repeated image", () => {
             }
         }));
 
-        const imageUrlToBase64Spy = spyOn(ImageService as any, 'imageUrlToBase64');
-
         const image: Image = await ImageService.get();
         expect(image.url).not.toBe(REPEATED_URL);
-        expect(imageUrlToBase64Spy).toHaveBeenCalledTimes(1);
     });
+});
+
+describe("imageToBase64 works as expected", () => {
+    it("should encode image to base64 properly", () => {
+        const imageData = fs.readFileSync('./test/ImageService/testImage.jpg');
+        const imageToBase64Spy = spyOn(ImageService as any, 'imageToBase64');
+        
+        const actualEncoding = imageToBase64Spy.call(ImageService, imageData);
+        const expectedEncoding = fs.readFileSync('./test/ImageService/testImage.b64', "base64").toString();
+
+        expect(actualEncoding).toBe(expectedEncoding);
+    })
 })

test/ImageService/testImage.b64

@@ -0,0 +1 @@
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