increase coverage in java-core units

Author: diegomarquezp

java-core/google-cloud-core/src/test/java/com/google/cloud/TimestampTest.java

@@ -335,4 +335,14 @@ void comparable() {
   void serialization() {
     reserializeAndAssert(Timestamp.parseTimestamp("9999-12-31T23:59:59.999999999Z"));
   }
+
+  @Test
+  void parseInvalidTimestampThreetenThrowsThreetenException() {
+    assertThrows(
+        org.threeten.bp.format.DateTimeParseException.class,
+        () -> Timestamp.parseTimestamp("00x1-01-01T00:00:00"));
+    assertThrows(
+        java.time.format.DateTimeParseException.class,
+        () -> Timestamp.parseTimestampDuration("00x1-01-01T00:00:00"));
+  }
 }

java-core/google-cloud-core/src/test/java/com/google/cloud/testing/BaseEmulatorHelperTest.java

@@ -16,7 +16,6 @@
 
 package com.google.cloud.testing;
 
-import static com.google.api.gax.util.TimeConversionUtils.toJavaTimeDuration;
 
 import com.google.api.client.util.Charsets;
 import com.google.cloud.ServiceOptions;
@@ -75,7 +74,8 @@ public void start() throws IOException, InterruptedException {
     @Override
     public void stop(org.threeten.bp.Duration timeout)
         throws IOException, InterruptedException, TimeoutException {
-      stopDuration(toJavaTimeDuration(timeout));
+      // we call the threeten method directly to confirm behavior
+      waitForProcess(timeout);
     }
 
     @Override
@@ -110,6 +110,26 @@ void testEmulatorHelper() throws IOException, InterruptedException, TimeoutExcep
     EasyMock.verify();
   }
 
+  @Test
+  void testEmulatorHelperThreeten() throws IOException, InterruptedException, TimeoutException {
+    Process process = EasyMock.createStrictMock(Process.class);
+    InputStream stream = new ByteArrayInputStream(BLOCK_UNTIL.getBytes(Charsets.UTF_8));
+    EmulatorRunner emulatorRunner = EasyMock.createStrictMock(EmulatorRunner.class);
+    EasyMock.expect(process.getInputStream()).andReturn(stream);
+    EasyMock.expect(emulatorRunner.isAvailable()).andReturn(true);
+    emulatorRunner.start();
+    EasyMock.expectLastCall();
+    EasyMock.expect(emulatorRunner.getProcess()).andReturn(process);
+    emulatorRunner.waitForDuration(java.time.Duration.ofMinutes(1));
+    EasyMock.expectLastCall().andReturn(0);
+    EasyMock.replay(process, emulatorRunner);
+    TestEmulatorHelper helper =
+        new TestEmulatorHelper(ImmutableList.of(emulatorRunner), BLOCK_UNTIL);
+    helper.start();
+    helper.stop(org.threeten.bp.Duration.ofMinutes(1));
+    EasyMock.verify();
+  }
+
   @Test
   void testEmulatorHelperDownloadWithRetries()
       throws IOException, InterruptedException, TimeoutException {