tested utils checkImageFormatValidity

src/helpers/utils.js

@@ -15,6 +15,7 @@ u.debounce = function(func, delay) {
  *
  * @async
  * @param {string} imageUrl - The url of the image
+ * @returns {bool} - Whether the image is in a valid format
  * @throws {Error} When loading the profile picture from a URL doesn't work, or it fails requirements.
  */
 u.checkImageFormatValidity = async function (imageUrl) {
@@ -24,15 +25,17 @@ u.checkImageFormatValidity = async function (imageUrl) {
         response = await fetch(imageUrl);
     }
     catch(e) {
-        throw new Error(`${enums.err.CANNOT_FETCH_RESOURCE}: {error.message}`);
+        throw new Error(`${enums.err.PROPIC_CANNOT_LOAD}: ${e.message}`);
     }
 
     try {
-        blobFile = response.blob();
+        blobFile = await response.blob();
         if (blobFile.size > 1000000 || !acceptableImages.includes(blobFile.type)) throw new Error(enums.err.PROPIC_FAILS_REQUIREMENTS);
+
+        return true;
     }
     catch(error) {
-        throw new Error(`${enums.err.PROPIC_CANNOT_LOAD}: ${error.message}`);
+        throw new Error(error.message);
     }
 }
 

tests/helpers/utils.test.js

@@ -1,15 +1,63 @@
 const {enums} = require("../../src/enums");
 
-const fetchMock = require('jest-fetch-mock');
-fetchMock.enableMocks();
-
 const {utils} = require("../../src/helpers/utils.js");
 
 describe('utils', () => {
 
+    const attachmentUrl = 'oya.png';
+    let blob;
+
     beforeEach(() => {
         jest.resetModules();
         jest.clearAllMocks();
+        blob = new Blob([JSON.stringify({attachmentUrl: attachmentUrl})], {type: 'image/png'});
+        global.fetch = jest.fn(() =>
+            Promise.resolve({
+                blob: () => Promise.resolve(blob),
+            })
+        );
+
+    })
+
+    describe('checkImageFormatValidity', () => {
+
+        test('calls fetch with imageUrl and returns true if no errors', async() => {
+            // Act
+            const res = await utils.checkImageFormatValidity(attachmentUrl);
+            // Assert
+            expect(res).toBe(true);
+            expect(fetch).toHaveBeenCalledTimes(1);
+            expect(fetch).toHaveBeenCalledWith(attachmentUrl);
+        })
+
+        test('throws error if fetch returns error', async() => {
+            // Arrange
+            global.fetch = jest.fn().mockImplementation(() =>{throw Error('error');});
+            // Act & Assert
+            await expect(utils.checkImageFormatValidity(attachmentUrl)).rejects.toThrow(`${enums.err.PROPIC_CANNOT_LOAD}: error`);
+        })
+
+        test('throws error if blob returns error', async() => {
+            // Arrange
+            global.fetch = jest.fn(() =>
+                Promise.resolve({
+                    blob: () => Promise.reject(new Error('error'))
+                }))
+            // Act & Assert
+            await expect(utils.checkImageFormatValidity(attachmentUrl)).rejects.toThrow('error');
+        })
+
+        test('throws error if blob in wrong format', async() => {
+            // Arrange
+            blob =  new Blob([JSON.stringify({attachmentUrl})], {type: 'text/html'});
+            global.fetch = jest.fn(() =>
+                Promise.resolve({
+                    blob: () => Promise.resolve(blob),
+                })
+            );
+            // Act & Assert
+            await expect(utils.checkImageFormatValidity(attachmentUrl)).rejects.toThrow(enums.err.PROPIC_FAILS_REQUIREMENTS);
+        })
     })
 
     afterEach(() => {