fix: address remaining test hygiene and consistency findings from PR review

Author: macastelaz

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

@@ -93,6 +93,7 @@ class ComputeEngineCredentialsTest extends BaseSerializationTest {
 
   @BeforeEach
   void setUp() throws IOException {
+    AgentIdentityUtils.clearCertInfoCache();
     envProvider = new TestEnvironmentProvider();
     // Inject our test environment reader into AgentIdentityUtils
     AgentIdentityUtils.setEnvReader(envProvider::getEnv);
@@ -117,10 +118,17 @@ public void sleep(long millis) {
   }
 
   @AfterEach
-  void tearDown() {
+  void tearDown() throws IOException {
     // Reset the mocks
+    AgentIdentityUtils.clearCertInfoCache();
     AgentIdentityUtils.resetTimeService();
     AgentIdentityUtils.setEnvReader(System::getenv);
+    if (tempDir != null) {
+      Files.walk(tempDir)
+          .sorted(java.util.Comparator.reverseOrder())
+          .map(Path::toFile)
+          .forEach(File::delete);
+    }
   }
 
   private static final String TOKEN_URL =

sdk-platform-java/gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPool.java

@@ -516,7 +516,7 @@ void refresh() {
       }
 
       // Double-check fingerprint inside the lock
-      if (currentDiskFingerprint.equals(this.activeCertFingerprint)) {
+      if (currentDiskFingerprint.equalsIgnoreCase(this.activeCertFingerprint)) {
         LOG.fine(
             "Channel pool was already refreshed by a concurrent thread, skipping duplicate refresh");
         return;

sdk-platform-java/gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/ChannelPoolTest.java

@@ -81,13 +81,18 @@
 class ChannelPoolTest {
   private static final int DEFAULT_AWAIT_TERMINATION_SEC = 10;
   private ChannelPool pool;
+  private java.nio.file.Path tempCert;
 
   @AfterEach
-  void cleanup() throws InterruptedException {
+  void cleanup() throws InterruptedException, IOException {
     if (pool != null) {
       pool.shutdown();
       pool.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
     }
+    if (tempCert != null) {
+      java.nio.file.Files.deleteIfExists(tempCert);
+      tempCert = null;
+    }
   }
 
   @Test
@@ -439,8 +444,7 @@ void channelReactiveMTlsRefreshShouldConditionallySwapChannels() throws IOExcept
         new FakeChannelFactory(ImmutableList.of(underlyingChannel1, underlyingChannel2));
 
     // Create a temp file to act as the cert
-    java.nio.file.Path tempCert = java.nio.file.Files.createTempFile("cert", ".pem");
-    tempCert.toFile().deleteOnExit();
+    tempCert = java.nio.file.Files.createTempFile("cert", ".pem");
 
     java.nio.file.Path clientCert = java.nio.file.Paths.get("src", "test", "resources", "client_cert.pem");
     java.nio.file.Files.copy(clientCert, tempCert, java.nio.file.StandardCopyOption.REPLACE_EXISTING);

sdk-platform-java/gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcCallContextTest.java

@@ -511,6 +511,5 @@ public void testEqualsAndHashCode() {
     org.junit.jupiter.api.Assertions.assertEquals(context1.hashCode(), context2.hashCode());
 
     org.junit.jupiter.api.Assertions.assertNotEquals(context1, context3);
-    org.junit.jupiter.api.Assertions.assertNotEquals(context1.hashCode(), context3.hashCode());
   }
 }

sdk-platform-java/gax-java/gax-httpjson/src/main/java/com/google/api/gax/httpjson/RefreshingHttpJsonChannel.java

@@ -147,7 +147,7 @@ public void refresh() {
       }
 
       // Double-check inside refreshLock
-      if (currentDiskFingerprint.equals(this.activeCertFingerprint)) {
+      if (currentDiskFingerprint.equalsIgnoreCase(this.activeCertFingerprint)) {
         LOG.fine(
             "HTTP/JSON channel was already refreshed by a concurrent thread, skipping duplicate refresh");
         return;

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/rpc/ServerStreamingAttemptCallableTest.java

@@ -29,6 +29,7 @@
  */
 package com.google.api.gax.rpc;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.mock;
 
 import com.google.api.core.AbstractApiFuture;
@@ -270,14 +271,11 @@ void testUnauthenticatedRefresh() {
     call.getController().getObserver().onError(initialError);
 
     // Should notify the outer future
-    Throwable outerError = null;
-    try {
-      fakeRetryingFuture.getAttemptResult().get(1, TimeUnit.SECONDS);
-    } catch (ExecutionException e) {
-      outerError = e.getCause();
-    } catch (Throwable e) {
-      outerError = e;
-    }
+    ExecutionException ee =
+        assertThrows(
+            ExecutionException.class,
+            () -> fakeRetryingFuture.getAttemptResult().get(1, TimeUnit.SECONDS));
+    Throwable outerError = ee.getCause();
     Mockito.verify(transportChannel).refresh();
     Truth.assertThat(outerError).isInstanceOf(ServerStreamingAttemptException.class);
     Truth.assertThat(((ServerStreamingAttemptException) outerError).hasSeenResponses()).isFalse();

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/rpc/StreamingCallableTest.java

@@ -129,7 +129,7 @@ void testClientStreamingCall() {
     ClientStreamingCallable<Integer, Integer> callable =
         stashCallable.withDefaultCallContext(defaultCallContext);
     callable.clientStreamingCall(observer);
-    org.junit.jupiter.api.Assertions.assertNotNull(stashCallable.getActualObserver());
+    assertSame(observer, stashCallable.getActualObserver());
     assertSame(defaultCallContext, stashCallable.getContext());
   }
 
@@ -158,7 +158,7 @@ void testClientStreamingCallWithContext() {
     ClientStreamingCallable<Integer, Integer> callable =
         stashCallable.withDefaultCallContext(FakeCallContext.createDefault());
     callable.clientStreamingCall(observer, context);
-    org.junit.jupiter.api.Assertions.assertNotNull(stashCallable.getActualObserver());
+    assertSame(observer, stashCallable.getActualObserver());
     FakeCallContext actualContext = (FakeCallContext) stashCallable.getContext();
     assertSame(channel, actualContext.getChannel());
     assertSame(credentials, actualContext.getCredentials());

sdk-platform-java/gax-java/gax/src/test/java/com/google/api/gax/rpc/mtls/CertificateBasedAccessTest.java

@@ -197,6 +197,16 @@ void testUseMtlsClientCertificateConfigMissingFile() {
     assertTrue(ex.getMessage().contains("configured but the file does not exist"));
   }
 
+  @Test
+  void testUseMtlsClientCertificateEnvTrueOverride() {
+    TestEnv env = new TestEnv();
+    env.set("GOOGLE_API_USE_CLIENT_CERTIFICATE", "true");
+
+    CertificateBasedAccess cba = createCba(env, new TestFileSystem());
+
+    assertTrue(cba.useMtlsClientCertificate());
+  }
+
   @Test
   void testUseMtlsClientCertificateConfigMalformedJson() {
     TestEnv env = new TestEnv();