Getting coverage up to 100% and testing for errors

.gitignore

@@ -1 +1,2 @@
+coverage
 node_modules

.npmignore

@@ -1,5 +1,6 @@
 .DS_Store
 .gitignore
+coverage
 src
 tests
 yarn.lock

tests/index.test.js

@@ -12,17 +12,28 @@ fetch.mockResponses(
   [ new Error('404 Not Found'), { status: 404 } ]
 );
 
-const mockFetch = fetchMultiple(mockUrls);
+const resolvingFetch = fetchMultiple(mockUrls);
+
+fetch.mockReject('404 Not Found');
+const failingFetch = fetchMultiple({ '/undefined.text': 'text' });
 
 it('works as a promise', () => {
-  expect(mockFetch.resolves);
+  expect(resolvingFetch.resolves);
 });
 
-it('returns the correct values', () => {
-  expect(mockFetch.then(data => {
+it('returns the correct values for functional endpoints', () => {
+  expect(resolvingFetch.then(data => {
     return data === {
       '/data.json': { data: true },
       'text.txt': 'Some example text'
     }
   }));
+});
+
+it('returns an error for failing endpoints', () => {
+  expect(failingFetch.then(data => {
+    return data === {
+      '/undefined.text': '404 Not Found'
+    }
+  }));
 });