fix(@aws-amplify/storage) correctly handle empty S3 list results (#5509)

aws-amplify · Apr 24, 2020 · d6fcb6a · d6fcb6a
1 parent fd45012
commit d6fcb6a
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Showing 2 changed files with 36 additions and 8 deletions.
diff --git a/packages/storage/__tests__/providers/AWSS3Provider-unit-test.ts b/packages/storage/__tests__/providers/AWSS3Provider-unit-test.ts
@@ -23,6 +23,9 @@ import { S3RequestPresigner } from '@aws-sdk/s3-request-presigner';
 
 S3Client.prototype.send = jest.fn(async command => {
 	if (command instanceof ListObjectsCommand) {
+		if (command.input.Prefix === 'public/emptyListResultsPath') {
+			return {};
+		}
 		return {
 			Contents: [
 				{
@@ -729,6 +732,28 @@ describe('StorageProvider test', () => {
 			spyon.mockClear();
 		});
 
+		test('list objects with zero results', async () => {
+			jest.spyOn(Credentials, 'get').mockImplementationOnce(() => {
+				return new Promise((res, rej) => {
+					res({});
+				});
+			});
+
+			const storage = new StorageProvider();
+			storage.configure(options);
+			const spyon = jest.spyOn(S3Client.prototype, 'send');
+
+			expect.assertions(2);
+			expect(
+				await storage.list('emptyListResultsPath', { level: 'public' })
+			).toEqual([]);
+			expect(spyon.mock.calls[0][0].input).toEqual({
+				Bucket: 'bucket',
+				Prefix: 'public/emptyListResultsPath',
+			});
+			spyon.mockClear();
+		});
+
 		test('list object with track', async () => {
 			jest.spyOn(Credentials, 'get').mockImplementationOnce(() => {
 				return new Promise((res, rej) => {

diff --git a/packages/storage/src/providers/AWSS3Provider.ts b/packages/storage/src/providers/AWSS3Provider.ts
@@ -405,14 +405,17 @@ export class AWSS3Provider implements StorageProvider {
 
 		try {
 			const response = await s3.send(listObjectsCommand);
-			const list = (response as any).Contents.map(item => {
-				return {
-					key: item.Key.substr(prefix.length),
-					eTag: item.ETag,
-					lastModified: item.LastModified,
-					size: item.Size,
-				};
-			});
+			let list = [];
+			if (response && response.Contents) {
+				list = response.Contents.map(item => {
+					return {
+						key: item.Key.substr(prefix.length),
+						eTag: item.ETag,
+						lastModified: item.LastModified,
+						size: item.Size,
+					};
+				});
+			}
 			dispatchStorageEvent(
 				track,
 				'list',