Switching to JUnit 5

.gitignore

@@ -6,6 +6,7 @@ gradle.properties
 
 # Ignore Gradle build output directory
 build
+bin
 
 #MacOS
 .DS_Store

build.gradle

@@ -42,10 +42,9 @@ compileJava {
 dependencies {
     implementation 'io.reactivex.rxjava3:rxjava:3.1.6'
     implementation 'io.reactivex.rxjava3:rxjava:3.1.6'
-
-    // Use JUnit test framework.
-    testImplementation 'junit:junit:4.13.2'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.3'
     testImplementation 'org.mockito:mockito-core:5.4.0'
+    testImplementation 'org.mockito:mockito-junit-jupiter:5.4.0'
 
     implementation platform('software.amazon.awssdk:bom:2.20.99')
 

src/test/java/software/amazon/nio/spi/s3/PosixLikePathRepresentationTest.java

@@ -5,9 +5,9 @@
 
 package software.amazon.nio.spi.s3;
 
-import org.junit.Test;
-
-import static org.junit.Assert.*;
+import org.junit.jupiter.api.Assertions;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 public class PosixLikePathRepresentationTest {
     String root = "/";
@@ -27,19 +27,19 @@ public class PosixLikePathRepresentationTest {
 
 
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void ofNullWithMore() {
-        PosixLikePathRepresentation.of(null, "foo");
+        assertThrows(IllegalArgumentException.class, () -> PosixLikePathRepresentation.of(null, "foo"));
     }
 
     @Test
     public void ofNull(){
         assertEquals(PosixLikePathRepresentation.EMPTY_PATH, PosixLikePathRepresentation.of(null));
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void ofEmptyWithMore(){
-        PosixLikePathRepresentation.of("", "foo");
+        assertThrows(IllegalArgumentException.class, () -> PosixLikePathRepresentation.of("", "foo"));
     }
 
     @Test

src/test/java/software/amazon/nio/spi/s3/S3ClientStoreTest.java

@@ -5,16 +5,9 @@
 
 package software.amazon.nio.spi.s3;
 
-import junit.framework.TestCase;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.InOrder;
-import org.mockito.Mock;
-import org.mockito.Spy;
-import org.mockito.junit.MockitoJUnitRunner;
 import software.amazon.awssdk.awscore.exception.AwsErrorDetails;
 import software.amazon.awssdk.http.SdkHttpResponse;
+import software.amazon.awssdk.regions.Region;
 import software.amazon.awssdk.services.s3.S3AsyncClient;
 import software.amazon.awssdk.services.s3.S3Client;
 import software.amazon.awssdk.services.s3.model.GetBucketLocationResponse;
@@ -23,13 +16,21 @@
 
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InOrder;
+import org.mockito.Mock;
 
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.*;
+import org.mockito.Spy;
+import org.mockito.junit.jupiter.MockitoExtension;
 
-@RunWith(MockitoJUnitRunner.class)
+@ExtendWith(MockitoExtension.class)
 @SuppressWarnings("unchecked")
-public class S3ClientStoreTest extends TestCase {
-
+public class S3ClientStoreTest {
     S3ClientStore instance;
 
     @Mock
@@ -38,17 +39,11 @@ public class S3ClientStoreTest extends TestCase {
     @Spy
     final S3ClientStore spyInstance = S3ClientStore.getInstance();
 
-    @Before
+    @BeforeEach
     public void setUp() throws Exception {
-        super.setUp();
         instance = S3ClientStore.getInstance();
     }
 
-    @Test
-    public void testGetInstanceReturnsSingleton() {
-        assertSame(S3ClientStore.getInstance(), instance);
-    }
-
     @Test
     public void testGetClientForNullBucketName() {
         assertEquals(S3ClientStore.DEFAULT_CLIENT, instance.getClientForBucketName(null));
@@ -227,14 +222,14 @@ public void testGenerateAsyncClientWith403Then301ResponsesNoHeader(){
 
     @Test
     public void testCaching() {
-        S3Client client = S3Client.create();
+        S3Client client = S3Client.builder().region(Region.US_EAST_1).build();
         doReturn(client).when(spyInstance).generateClient("test-bucket");
 
         final S3Client client1 = spyInstance.getClientForBucketName("test-bucket");
         verify(spyInstance).generateClient("test-bucket");
         assertSame(client1, client);
 
-        S3Client differentClient = S3Client.create();
+        S3Client differentClient = S3Client.builder().region(Region.US_EAST_1).build();
         assertNotSame(client, differentClient);
 
         lenient().doReturn(differentClient).when(spyInstance).generateClient("test-bucket");
@@ -247,14 +242,14 @@ public void testCaching() {
 
     @Test
     public void testAsyncCaching() {
-        S3AsyncClient client = S3AsyncClient.create();
+        S3AsyncClient client = S3AsyncClient.builder().region(Region.US_EAST_1).build();
         doReturn(client).when(spyInstance).generateAsyncClient("test-bucket");
 
         final S3AsyncClient client1 = spyInstance.getAsyncClientForBucketName("test-bucket");
         verify(spyInstance).generateAsyncClient("test-bucket");
         assertSame(client1, client);
 
-        S3AsyncClient differentClient = S3AsyncClient.create();
+        S3AsyncClient differentClient = S3AsyncClient.builder().region(Region.US_EAST_1).build();
         assertNotSame(client, differentClient);
 
         lenient().doReturn(differentClient).when(spyInstance).generateAsyncClient("test-bucket");

src/test/java/software/amazon/nio/spi/s3/S3FileSystemProviderTest.java

@@ -5,12 +5,8 @@
 
 package software.amazon.nio.spi.s3;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
-import org.mockito.junit.MockitoJUnitRunner;
 import software.amazon.awssdk.core.async.AsyncRequestBody;
 import software.amazon.awssdk.http.SdkHttpResponse;
 import software.amazon.awssdk.services.s3.S3AsyncClient;
@@ -35,12 +31,19 @@
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import org.mockito.junit.jupiter.MockitoExtension;
 
 @SuppressWarnings("unchecked")
-@RunWith(MockitoJUnitRunner.class)
+@ExtendWith(MockitoExtension.class)
 public class S3FileSystemProviderTest {
 
     S3FileSystemProvider provider;
@@ -49,11 +52,11 @@ public class S3FileSystemProviderTest {
     @Mock
     S3AsyncClient mockClient;
 
-    @Before
+    @BeforeEach
     public void init() {
         provider = new S3FileSystemProvider();
         fs = new S3FileSystem("s3://mybucket", provider);
-        when(mockClient.headObject(any(Consumer.class))).thenReturn(
+        lenient().when(mockClient.headObject(any(Consumer.class))).thenReturn(
                 CompletableFuture.supplyAsync(() -> HeadObjectResponse.builder().contentLength(100L).build()));
     }
 
@@ -262,26 +265,26 @@ public void checkAccessWithoutException() throws IOException, ExecutionException
         provider.checkAccess(mockClient, foo);
     }
 
-    @Test(expected = AccessDeniedException.class)
+    @Test
     public void checkAccessWhenAccessDenied() throws IOException, ExecutionException, InterruptedException {
         when(mockClient.headObject(any(Consumer.class))).thenReturn(CompletableFuture.supplyAsync(() ->
                 HeadObjectResponse.builder()
                         .sdkHttpResponse(SdkHttpResponse.builder().statusCode(403).build())
                         .build()));
 
         S3Path foo = fs.getPath("/foo");
-        provider.checkAccess(mockClient, foo);
+        assertThrows(AccessDeniedException.class, () -> provider.checkAccess(mockClient, foo));
     }
 
-    @Test(expected = NoSuchFileException.class)
+    @Test
     public void checkAccessWhenNoSuchFile() throws IOException, ExecutionException, InterruptedException {
         when(mockClient.headObject(any(Consumer.class))).thenReturn(CompletableFuture.supplyAsync(() ->
                 HeadObjectResponse.builder()
                         .sdkHttpResponse(SdkHttpResponse.builder().statusCode(404).build())
                         .build()));
 
         S3Path foo = fs.getPath("/foo");
-        provider.checkAccess(mockClient, foo);
+        assertThrows(NoSuchFileException.class, () -> provider.checkAccess(mockClient, foo));
     }
 
     @Test
@@ -304,10 +307,10 @@ public void getFileAttributeView() {
         assertNotNull(fileAttributeView1);
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void getFileAttributeViewIllegalArg() {
         S3Path foo = fs.getPath("/foo");
-        final FileAttributeView fileAttributeView = provider.getFileAttributeView(foo, FileAttributeView.class);
+        assertThrows(IllegalArgumentException.class, () -> provider.getFileAttributeView(foo, FileAttributeView.class));
     }
 
     @Test
@@ -344,9 +347,9 @@ public void testReadAttributes() {
         assertEquals(Collections.emptyMap(), provider.readAttributes(mockClient, fooDir, "*"));
     }
 
-    @Test(expected = UnsupportedOperationException.class)
+    @Test
     public void setAttribute() {
         S3Path foo = fs.getPath("/foo");
-        provider.setAttribute(foo, "x", "y");
+        assertThrows(UnsupportedOperationException.class, () -> provider.setAttribute(foo, "x", "y"));
     }
 }

src/test/java/software/amazon/nio/spi/s3/S3FileSystemTest.java

@@ -5,27 +5,31 @@
 
 package software.amazon.nio.spi.s3;
 
-import org.junit.Before;
-import org.junit.Test;
-
 import java.io.IOException;
 import java.net.URI;
 import java.nio.file.FileSystems;
 import java.nio.file.Path;
 import java.util.Collections;
 import java.util.Iterator;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import software.amazon.awssdk.services.s3.S3Client;
 
+@ExtendWith(MockitoExtension.class)
 public class S3FileSystemTest {
     S3FileSystemProvider provider;
     URI s3Uri = URI.create("s3://mybucket/some/path/to/object.txt");
     S3FileSystem s3FileSystem;
 
-    @Before
+    @Mock
+    S3Client mockClient; //client used to determine bucket location
+
+    @BeforeEach
     public void init() {
         this.provider = new S3FileSystemProvider();
         s3FileSystem = (S3FileSystem) this.provider.newFileSystem(s3Uri, Collections.emptyMap());
@@ -42,12 +46,12 @@ public void getSeparator() {
     public void close() throws IOException {
         assertEquals(0, s3FileSystem.getOpenChannels().size());
         s3FileSystem.close();
-        assertFalse("File system should return false from isOpen when closed has been called", s3FileSystem.isOpen());
+        assertFalse(s3FileSystem.isOpen(), "File system should return false from isOpen when closed has been called");
     }
 
     @Test
     public void isOpen() {
-        assertTrue("File system should be open when newly created", s3FileSystem.isOpen());
+        assertTrue(s3FileSystem.isOpen(), "File system should be open when newly created");
     }
 
     @Test
@@ -94,10 +98,11 @@ public void getPathMatcher() {
                 s3FileSystem.getPathMatcher("glob:*.*").getClass());
     }
 
-
-    @Test(expected = UnsupportedOperationException.class)
-    //thrown because cannot be modified
+    @Test
     public void testGetOpenChannelsIsNotModifiable() {
-        s3FileSystem.getOpenChannels().add(null);
+        //
+        // thrown because cannot be modified
+        //
+        assertThrows(UnsupportedOperationException.class, () -> s3FileSystem.getOpenChannels().add(null));
     }
 }