fix exception in ComputeEngineCredentials, add test. Edit exception tests to use assertThrows.

Author: zhumin8

oauth2_http/java/com/google/auth/oauth2/ComputeEngineCredentials.java

@@ -609,10 +609,8 @@ public byte[] sign(byte[] toSign) {
       throw ex;
     } catch (RuntimeException ex) {
       throw new SigningException("Signing failed", ex);
-    } catch (IOException e) {
-      // Throwing an IOException would be a breaking change, so wrap it here.
-      // This should not happen for this credential type.
-      throw new IllegalStateException("Failed to get universe domain", e);
+    } catch (IOException ex) {
+      throw new SigningException("Failed to sign: Error obtaining universe domain", ex);
     }
   }
 

oauth2_http/java/com/google/auth/oauth2/IamUtils.java

@@ -114,7 +114,8 @@ private static String getSignature(
       HttpRequestFactory factory)
       throws IOException {
     String signBlobUrl =
-        String.format(OAuth2Utils.IAM_SIGN_BLOB_ENDPOINT_FORMAT, universeDomain, serviceAccountEmail);
+        String.format(
+            OAuth2Utils.IAM_SIGN_BLOB_ENDPOINT_FORMAT, universeDomain, serviceAccountEmail);
     GenericUrl genericUrl = new GenericUrl(signBlobUrl);
 
     GenericData signRequest = new GenericData();

oauth2_http/javatests/com/google/auth/oauth2/ComputeEngineCredentialsTest.java

@@ -66,6 +66,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
+import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -541,7 +542,7 @@ public LowLevelHttpResponse execute() throws IOException {
   }
 
   @Test
-  public void sign_sameAs() throws IOException {
+  public void sign_sameAs() {
     MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
     String defaultAccountEmail = "[email protected]";
     byte[] expectedSignature = {0xD, 0xE, 0xA, 0xD};
@@ -555,21 +556,36 @@ public void sign_sameAs() throws IOException {
   }
 
   @Test
-  public void sign_getAccountFails() throws IOException {
+  public void sign_getUniverseException() {
+    MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
+
+    String defaultAccountEmail = "[email protected]";
+    transportFactory.transport.setServiceAccountEmail(defaultAccountEmail);
+    ComputeEngineCredentials credentials =
+        ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
+
+    transportFactory.transport.setRequestStatusCode(501);
+    Assert.assertThrows(IOException.class, credentials::getUniverseDomain);
+
+    byte[] expectedSignature = {0xD, 0xE, 0xA, 0xD};
+    SigningException signingException =
+        Assert.assertThrows(SigningException.class, () -> credentials.sign(expectedSignature));
+    assertEquals("Failed to sign: Error obtaining universe domain", signingException.getMessage());
+  }
+
+  @Test
+  public void sign_getAccountFails() {
     MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
     byte[] expectedSignature = {0xD, 0xE, 0xA, 0xD};
 
     transportFactory.transport.setSignature(expectedSignature);
     ComputeEngineCredentials credentials =
         ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-    try {
-      credentials.sign(expectedSignature);
-      fail("Should not be able to use credential without exception.");
-    } catch (SigningException ex) {
-      assertNotNull(ex.getMessage());
-      assertNotNull(ex.getCause());
-    }
+    SigningException exception =
+        Assert.assertThrows(SigningException.class, () -> credentials.sign(expectedSignature));
+    assertNotNull(exception.getMessage());
+    assertNotNull(exception.getCause());
   }
 
   @Test
@@ -601,15 +617,13 @@ public LowLevelHttpResponse execute() throws IOException {
     ComputeEngineCredentials credentials =
         ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-    try {
-      byte[] bytes = {0xD, 0xE, 0xA, 0xD};
-      credentials.sign(bytes);
-      fail("Signing should have failed");
-    } catch (SigningException e) {
-      assertEquals("Failed to sign the provided bytes", e.getMessage());
-      assertNotNull(e.getCause());
-      assertTrue(e.getCause().getMessage().contains("403"));
-    }
+    byte[] bytes = {0xD, 0xE, 0xA, 0xD};
+
+    SigningException exception =
+        Assert.assertThrows(SigningException.class, () -> credentials.sign(bytes));
+    assertEquals("Failed to sign the provided bytes", exception.getMessage());
+    assertNotNull(exception.getCause());
+    assertTrue(exception.getCause().getMessage().contains("403"));
   }
 
   @Test
@@ -641,15 +655,13 @@ public LowLevelHttpResponse execute() throws IOException {
     ComputeEngineCredentials credentials =
         ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-    try {
-      byte[] bytes = {0xD, 0xE, 0xA, 0xD};
-      credentials.sign(bytes);
-      fail("Signing should have failed");
-    } catch (SigningException e) {
-      assertEquals("Failed to sign the provided bytes", e.getMessage());
-      assertNotNull(e.getCause());
-      assertTrue(e.getCause().getMessage().contains("500"));
-    }
+    byte[] bytes = {0xD, 0xE, 0xA, 0xD};
+
+    SigningException exception =
+        Assert.assertThrows(SigningException.class, () -> credentials.sign(bytes));
+    assertEquals("Failed to sign the provided bytes", exception.getMessage());
+    assertNotNull(exception.getCause());
+    assertTrue(exception.getCause().getMessage().contains("500"));
   }
 
   @Test
@@ -674,14 +686,11 @@ public LowLevelHttpResponse execute() throws IOException {
     ComputeEngineCredentials credentials =
         ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-    try {
-      credentials.refreshAccessToken();
-      fail("Should have failed");
-    } catch (IOException e) {
-      assertTrue(e.getCause().getMessage().contains("503"));
-      assertTrue(e instanceof GoogleAuthException);
-      assertTrue(((GoogleAuthException) e).isRetryable());
-    }
+    IOException exception =
+        Assert.assertThrows(IOException.class, () -> credentials.refreshAccessToken());
+    assertTrue(exception.getCause().getMessage().contains("503"));
+    assertTrue(exception instanceof GoogleAuthException);
+    assertTrue(((GoogleAuthException) exception).isRetryable());
   }
 
   @Test
@@ -714,12 +723,9 @@ public LowLevelHttpResponse execute() throws IOException {
       ComputeEngineCredentials credentials =
           ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-      try {
-        credentials.refreshAccessToken();
-        fail("Should have failed");
-      } catch (IOException e) {
-        assertFalse(e instanceof GoogleAuthException);
-      }
+      IOException exception =
+          Assert.assertThrows(IOException.class, () -> credentials.refreshAccessToken());
+      assertTrue(exception instanceof GoogleAuthException);
     }
   }
 
@@ -889,15 +895,13 @@ public LowLevelHttpResponse execute() throws IOException {
     ComputeEngineCredentials credentials =
         ComputeEngineCredentials.newBuilder().setHttpTransportFactory(transportFactory).build();
 
-    try {
-      byte[] bytes = {0xD, 0xE, 0xA, 0xD};
-      credentials.sign(bytes);
-      fail("Signing should have failed");
-    } catch (SigningException e) {
-      assertEquals("Failed to sign the provided bytes", e.getMessage());
-      assertNotNull(e.getCause());
-      assertTrue(e.getCause().getMessage().contains("Empty content"));
-    }
+    byte[] bytes = {0xD, 0xE, 0xA, 0xD};
+
+    SigningException exception =
+        Assert.assertThrows(SigningException.class, () -> credentials.sign(bytes));
+    assertEquals("Failed to sign the provided bytes", exception.getMessage());
+    assertNotNull(exception.getCause());
+    assertTrue(exception.getCause().getMessage().contains("Empty content"));
   }
 
   @Test