Implemented GET /images endpoint with params

src/controllers/ImageController.ts

@@ -1,6 +1,7 @@
 import { Request, Response } from "express";
 import imageService from "../services/ImageService";
 import mongoose, { mongo } from "mongoose";
+import { Image } from "../models/ImageModel";
 
 class ImageController {
   async getImageById(req: Request, res: Response) {
@@ -20,12 +21,22 @@ class ImageController {
     }
   }
 
-  async getAllImages(_: Request, res: Response): Promise<void> {
+  async getAllImages(req: Request, res: Response): Promise<void> {
     try {
-      const images = await imageService.findAll();
+      if (req.query.status !== undefined && !["consumed", "unavailable", "available"].includes(req.query.status as string)) {
+        throw TypeError("if present, `status` should have the values `consumed`, `unavailable`, or `available`")
+      }
+      const limit = req.query.limit ? Number(req.query.limit) : undefined;
+      const status = req.query.status ? req.query.status as Image["status"] : undefined;
+
+      const images = await imageService.findAll(limit, status);
       res.json({ images });
     } catch (error) {
-      res.status(500).json({ error: "Internal Server Error" });
+      if (error instanceof TypeError) {
+        res.status(400).json({ error });
+      } else {
+        res.status(500).json({ error: "Internal Server Error" });
+      }
     }
   }
 
@@ -47,7 +58,7 @@ class ImageController {
         res.status(400).json({ error: error.message });
       } else {
         // Return 500 in other case
-        res.status(500).json({ error: error });
+        res.status(500).json({ error });
       }
     }
   }

src/models/ImageModel.ts

@@ -1,9 +1,9 @@
 import mongoose, { Document } from "mongoose";
 
 export interface Image extends Document {
-  url: String;
-  enum: "consumed" | "unavailable" | "available";
-  tags?: String[];
+  url: string;
+  status: "consumed" | "unavailable" | "available";
+  tags?: string[];
 }
 
 const ImageSchema = new mongoose.Schema(

src/services/ImageService.ts

@@ -5,10 +5,23 @@ class ImageService {
     const image = await imageModel.findOne({ _id: id });
     return image;
   }
-  async findAll(): Promise<Image[]> {
-    const allImages = await imageModel.find();
+
+  async findAll(limit?: number, status?: Image["status"]): Promise<Image[]> {
+    const typeError = TypeError("if present, `limit` must be a non-negative integer");
+    const filter = status !== undefined ? { status } : {};
+    let query = imageModel.find(filter);
+    if (limit !== undefined) {
+      if (Number.isInteger(limit)) {
+        if (limit > 0) query = query.limit(limit);
+        else if (limit < 0) throw typeError;
+      } else {
+        throw typeError;
+      }
+    }
+    const allImages = await query;
     return allImages;
   }
+
   async add(image: Image): Promise<Image> {
     const newImage = await imageModel.create(image);
     return newImage;

tests/app.test.ts

@@ -3,6 +3,8 @@ import request, { Response } from "supertest";
 import app, { startApp } from "../src/app";
 import imageService from "../src/services/ImageService";
 import populateDatabase from "./populateDatabase";
+import { Image } from "../src/models/ImageModel";
+import { faker } from "@faker-js/faker";
 
 const imageServiceOriginal = imageService;
 
@@ -73,7 +75,7 @@ describe("GET /images works properly", async () => {
   it("should return 500 for an error on the service", async () => {
     mock.module("../src/services/ImageService", () => ({
       default: {
-        add: () => {
+        findAll: () => {
           throw new Error("This is an expected testing error");
         },
       },
@@ -83,6 +85,68 @@ describe("GET /images works properly", async () => {
 
     expect(res.status).toBe(500);
   });
+
+  it("should return 400 for an invalid status param value", async () => {
+    const res = await request(app).get("/images?status=foo");
+    expect(res.statusCode).toBe(400);
+  });
+
+  it("should return 200 for a request with valid status param", async () => {
+    const status = faker.helpers.arrayElement(["consumed", "available", "unavailable"])
+    const res = await request(app).get(`/images?status=${status}`);
+    expect(res.statusCode).toBe(200);
+  });
+
+  it("should only have the requested status in the images", async () => {
+    const status = faker.helpers.arrayElement(["consumed", "available", "unavailable"])
+    const res = await request(app).get(`/images?status=${status}`);
+    expect(res.body.images
+      .map((image: Image) => image.status)
+      .every((imageStatus: string) => imageStatus === status)).toBeTrue();
+  });
+
+  it("should return 400 for a floating point value in limit value", async () => {
+    const res = await request(app).get("/images?limit=2.4");
+    expect(res.statusCode).toBe(400);
+  });
+
+  it("should return 400 for a negative value in limit value", async () => {
+    const res = await request(app).get("/images?limit=-1");
+    expect(res.statusCode).toBe(400);
+  });
+
+  it("should return 400 for a NaN limit value", async () => {
+    const res = await request(app).get("/images?limit=foo");
+    expect(res.statusCode).toBe(400);
+  });
+
+  it("should return 200 for a request with valid limit param", async () => {
+    const limit = faker.number.int({ min: 5, max: 50 });
+    const res = await request(app).get(`/images?limit=${limit}`);
+    expect(res.statusCode).toBe(200);
+  });
+
+  it("should return 200 for a request with valid limit param", async () => {
+    const limit = faker.number.int({ min: 5, max: 50 });
+    const res = await request(app).get(`/images?limit=${limit}`);
+    expect(res.body.images.length).toBeLessThanOrEqual(limit);
+  });
+
+  it("should return 200 for a request with both valid params", async () => {
+    const res = await request(app).get("/images?limit=3&status=available");
+    expect(res.statusCode).toBe(200);
+  });
+
+  it("should return the same ids using limit=0 and using no limit parameter", async () => {
+    const resLimit0 = await request(app).get("/images?limit=0");
+    const resNoLimit = await request(app).get("/images");
+
+    const ids1 = resNoLimit.body.images.map((image: Image) => image._id);
+    const ids2 = resLimit0.body.images.map((image: Image) => image._id);
+
+    expect(ids1.length).toBe(ids2.length);
+    ids1.forEach((id: string) => expect(ids2).toContain(id));
+  })
 });
 
 describe("POST /images works properly", () => {
@@ -178,7 +242,7 @@ describe("POST /images works properly", () => {
   });
 });
 
-describe("/images/:id works properly", () => {
+describe("GET /images/:id works properly", () => {
   it("should return 200 for existing ids", async () => {
     const list = await request(app).get("/images");
     const id = list.body.images[0]._id;