Merge pull request #1063 from christiaan/master_fix-coverUrl-thows-unexpected-error

Bugfix calling coverUrl throws error on book without cover

documentation/md/API.md

@@ -134,9 +134,9 @@ Set headers request should use
 
 ### coverUrl
 
-Get the cover url
+Get the cover url if there is a cover
 
-Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)>** Promise resolves with url string
+Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[?string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)>** Promise resolves with maybe a url string
 
 ### getRange
 

src/book.js

@@ -661,19 +661,20 @@ class Book {
 
 	/**
 	 * Get the cover url
-	 * @return {Promise<string>} coverUrl
+	 * @return {Promise<?string>} coverUrl
 	 */
 	coverUrl() {
-		var retrieved = this.loaded.cover.
-			then((url) => {
-				if(this.archived) {
-					return this.archive.createUrl(this.cover);
-				}else{
-					return this.cover;
-				}
-			});
+		return this.loaded.cover.then(() => {
+			if (!this.cover) {
+				return null;
+			}
 
-		return retrieved;
+			if (this.archived) {
+				return this.archive.createUrl(this.cover);
+			} else {
+				return this.cover;
+			}
+		});
 	}
 
 	/**

test/book.js

@@ -50,4 +50,18 @@ describe('Book', function() {
 			assert( /^blob:http:\/\/localhost:9876\/[^\/]+$/.test(coverUrl), "cover url is available and a blob: url" );
 		});
 	});
+
+	describe('Archived epub without cover', function() {
+		var book = new Book("/fixtures/alice_without_cover.epub");
+
+		it('should open a archived epub', async function() {
+			await book.opened
+			assert.equal(book.isOpen, true, "book is opened");
+			assert(book.archive, "book is unarchived");
+		});
+		it('should have a empty coverUrl', async function() {
+			let coverUrl = await book.coverUrl()
+			assert.equal(coverUrl, null, "cover url should be null" );
+		});
+	});
 });

types/book.d.ts

@@ -65,7 +65,7 @@ export default class Book {
 
     canonical(path: string): string;
 
-    coverUrl(): Promise<string>;
+    coverUrl(): Promise<string | null>;
 
     destroy(): void;