Use backported JUnit exceptThrows and assertThrows in metrics library

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=176584707

javatests/google/registry/monitoring/metrics/CounterTest.java

@@ -15,22 +15,18 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import org.joda.time.Instant;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 /** Unit tests for {@link Counter}. */
 @RunWith(JUnit4.class)
 public class CounterTest {
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testGetCardinality_reflectsCurrentCardinality() {
     Counter counter =
@@ -59,11 +55,12 @@ public class CounterTest {
             ImmutableSet.of(
                 LabelDescriptor.create("label1", "bar"), LabelDescriptor.create("label2", "bar")));
 
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage(
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> counter.increment("blah"));
+    assertThat(thrown)
+        .hasMessageThat()
+        .contains(
             "The count of labelValues must be equal to the underlying Metric's count of labels.");
-
-    counter.increment("blah");
   }
 
   @Test
@@ -122,9 +119,9 @@ public class CounterTest {
             "vdn",
             ImmutableSet.of(LabelDescriptor.create("label1", "bar")));
 
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("The offset provided must be non-negative");
-    counter.incrementBy(-1L, "foo");
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> counter.incrementBy(-1L, "foo"));
+    assertThat(thrown).hasMessageThat().contains("The offset provided must be non-negative");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/CustomFitterTest.java

@@ -15,35 +15,31 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedSet;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 /** Tests for {@link CustomFitter}. */
 @RunWith(JUnit4.class)
 public class CustomFitterTest {
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testCreateCustomFitter_emptyBounds_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("boundaries must not be empty");
-
-    CustomFitter.create(ImmutableSet.<Double>of());
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> CustomFitter.create(ImmutableSet.<Double>of()));
+    assertThat(thrown).hasMessageThat().contains("boundaries must not be empty");
   }
 
   @Test
   public void testCreateCustomFitter_outOfOrderBounds_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("boundaries must be sorted");
-
-    CustomFitter.create(ImmutableSet.of(2.0, 0.0));
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> CustomFitter.create(ImmutableSet.of(2.0, 0.0)));
+    assertThat(thrown).hasMessageThat().contains("boundaries must be sorted");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/EventMetricTest.java

@@ -15,6 +15,7 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableRangeMap;
@@ -22,9 +23,7 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Range;
 import org.joda.time.Instant;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -34,9 +33,6 @@ public class EventMetricTest {
 
   private final DistributionFitter distributionFitter = CustomFitter.create(ImmutableSet.of(5.0));
   private EventMetric metric;
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Before
   public void setUp() {
     metric =
@@ -67,11 +63,12 @@ public class EventMetricTest {
 
   @Test
   public void testIncrementBy_wrongLabelValueCount_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage(
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> metric.record(1.0, "blah", "blah"));
+    assertThat(thrown)
+        .hasMessageThat()
+        .contains(
             "The count of labelValues must be equal to the underlying Metric's count of labels.");
-
-    metric.record(1.0, "blah", "blah");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/ExponentialFitterTest.java

@@ -15,57 +15,49 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 /** Unit tests for {@link ExponentialFitter}. */
 @RunWith(JUnit4.class)
 public class ExponentialFitterTest {
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testCreateExponentialFitter_zeroNumIntervals_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("numFiniteIntervals must be greater than 0");
-
-    ExponentialFitter.create(0, 3.0, 1.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> ExponentialFitter.create(0, 3.0, 1.0));
+    assertThat(thrown).hasMessageThat().contains("numFiniteIntervals must be greater than 0");
   }
 
   @Test
   public void testCreateExponentialFitter_negativeNumIntervals_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("numFiniteIntervals must be greater than 0");
-
-    ExponentialFitter.create(-1, 3.0, 1.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> ExponentialFitter.create(-1, 3.0, 1.0));
+    assertThat(thrown).hasMessageThat().contains("numFiniteIntervals must be greater than 0");
   }
 
   @Test
   public void testCreateExponentialFitter_invalidBase_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("base must be greater than 1");
-
-    ExponentialFitter.create(3, 0.5, 1.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> ExponentialFitter.create(3, 0.5, 1.0));
+    assertThat(thrown).hasMessageThat().contains("base must be greater than 1");
   }
 
   @Test
   public void testCreateExponentialFitter_zeroScale_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("scale must not be 0");
-
-    ExponentialFitter.create(3, 2.0, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> ExponentialFitter.create(3, 2.0, 0.0));
+    assertThat(thrown).hasMessageThat().contains("scale must not be 0");
   }
 
   @Test
   public void testCreateExponentialFitter_NanScale_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-
-    ExponentialFitter.create(3, 2.0, Double.NaN);
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> ExponentialFitter.create(3, 2.0, Double.NaN));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/FibonacciFitterTest.java

@@ -15,7 +15,7 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableList;
 import org.junit.Test;
@@ -28,23 +28,17 @@ public class FibonacciFitterTest {
 
   @Test
   public void testCreate_maxBucketSizeNegative_throwsException() {
-    try {
-      FibonacciFitter.create(-1);
-      fail("Expected exception");
-    } catch (IllegalArgumentException e) {
+    IllegalArgumentException e =
+        expectThrows(IllegalArgumentException.class, () -> FibonacciFitter.create(-1));
     assertThat(e).hasMessageThat().isEqualTo("maxBucketSize must be greater than 0");
   }
-  }
 
   @Test
   public void testCreate_maxBucketSizeZero_throwsException() {
-    try {
-      FibonacciFitter.create(0);
-      fail("Expected exception");
-    } catch (IllegalArgumentException e) {
+    IllegalArgumentException e =
+        expectThrows(IllegalArgumentException.class, () -> FibonacciFitter.create(0));
     assertThat(e).hasMessageThat().isEqualTo("maxBucketSize must be greater than 0");
   }
-  }
 
   @Test
   public void testCreate_maxBucketSizeOne_createsTwoBoundaries() {

javatests/google/registry/monitoring/metrics/JUnitBackports.java

@@ -0,0 +1,122 @@
+package google.registry.monitoring.metrics;
+
+/**
+ * A testing utility class that contains backports of useful but not yet released JUnit methods.
+ *
+ * <p>All of this code was taken directly from
+ * https://github.com/junit-team/junit4/blob/a832c5afe5b0e7c2590d057a1a49a344d207f8a0/src/main/java/org/junit/Assert.java
+ */
+public class JUnitBackports {
+  // TODO(b/68257761): Delete these and switch over to JUnit 4.13 methods upon release.
+
+  /**
+   * This interface facilitates the use of expectThrows from Java 8. It allows method references to
+   * void methods (that declare checked exceptions) to be passed directly into expectThrows without
+   * wrapping. It is not meant to be implemented directly.
+   *
+   * @since 4.13
+   */
+  public interface ThrowingRunnable {
+    void run() throws Throwable;
+  }
+
+  /**
+   * Asserts that {@code runnable} throws an exception of type {@code expectedThrowable} when
+   * executed. If it does not throw an exception, an {@link AssertionError} is thrown. If it throws
+   * the wrong type of exception, an {@code AssertionError} is thrown describing the mismatch; the
+   * exception that was actually thrown can be obtained by calling {@link AssertionError#getCause}.
+   *
+   * @param expectedThrowable the expected type of the exception
+   * @param runnable a function that is expected to throw an exception when executed
+   * @since 4.13
+   */
+  public static void assertThrows(
+      Class<? extends Throwable> expectedThrowable, ThrowingRunnable runnable) {
+    expectThrows(expectedThrowable, runnable);
+  }
+
+  /**
+   * Asserts that {@code runnable} throws an exception of type {@code expectedThrowable} when
+   * executed. If it does, the exception object is returned. If it does not throw an exception, an
+   * {@link AssertionError} is thrown. If it throws the wrong type of exception, an {@code
+   * AssertionError} is thrown describing the mismatch; the exception that was actually thrown can
+   * be obtained by calling {@link AssertionError#getCause}.
+   *
+   * @param expectedThrowable the expected type of the exception
+   * @param runnable a function that is expected to throw an exception when executed
+   * @return the exception thrown by {@code runnable}
+   * @since 4.13
+   */
+  public static <T extends Throwable> T expectThrows(
+      Class<T> expectedThrowable, ThrowingRunnable runnable) {
+    try {
+      runnable.run();
+    } catch (Throwable actualThrown) {
+      if (expectedThrowable.isInstance(actualThrown)) {
+        @SuppressWarnings("unchecked")
+        T retVal = (T) actualThrown;
+        return retVal;
+      } else {
+        String expected = formatClass(expectedThrowable);
+        Class<? extends Throwable> actualThrowable = actualThrown.getClass();
+        String actual = formatClass(actualThrowable);
+        if (expected.equals(actual)) {
+          // There must be multiple class loaders. Add the identity hash code so the message
+          // doesn't say "expected: java.lang.String<my.package.MyException> ..."
+          expected += "@" + Integer.toHexString(System.identityHashCode(expectedThrowable));
+          actual += "@" + Integer.toHexString(System.identityHashCode(actualThrowable));
+        }
+        String mismatchMessage = format("unexpected exception type thrown;", expected, actual);
+
+        // The AssertionError(String, Throwable) ctor is only available on JDK7.
+        AssertionError assertionError = new AssertionError(mismatchMessage);
+        assertionError.initCause(actualThrown);
+        throw assertionError;
+      }
+    }
+    String message =
+        String.format(
+            "expected %s to be thrown, but nothing was thrown", formatClass(expectedThrowable));
+    throw new AssertionError(message);
+  }
+
+  static String format(String message, Object expected, Object actual) {
+    String formatted = "";
+    if (message != null && !"".equals(message)) {
+      formatted = message + " ";
+    }
+    String expectedString = String.valueOf(expected);
+    String actualString = String.valueOf(actual);
+    if (equalsRegardingNull(expectedString, actualString)) {
+      return formatted
+          + "expected: "
+          + formatClassAndValue(expected, expectedString)
+          + " but was: "
+          + formatClassAndValue(actual, actualString);
+    } else {
+      return formatted + "expected:<" + expectedString + "> but was:<" + actualString + ">";
+    }
+  }
+
+  private static String formatClass(Class<?> value) {
+    String className = value.getCanonicalName();
+    return className == null ? value.getName() : className;
+  }
+
+  private static String formatClassAndValue(Object value, String valueString) {
+    String className = value == null ? "null" : value.getClass().getName();
+    return className + "<" + valueString + ">";
+  }
+
+  private static boolean equalsRegardingNull(Object expected, Object actual) {
+    if (expected == null) {
+      return actual == null;
+    }
+
+    return isEquals(expected, actual);
+  }
+
+  private static boolean isEquals(Object expected, Object actual) {
+    return expected.equals(actual);
+  }
+}

javatests/google/registry/monitoring/metrics/LabelDescriptorTest.java

@@ -14,9 +14,10 @@
 
 package google.registry.monitoring.metrics;
 
-import org.junit.Rule;
+import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
+
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -24,27 +25,26 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class LabelDescriptorTest {
 
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testCreate_invalidLabel_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Label name must match the regex");
-    LabelDescriptor.create("@", "description");
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> LabelDescriptor.create("@", "description"));
+    assertThat(thrown).hasMessageThat().contains("Label name must match the regex");
   }
 
   @Test
   public void testCreate_blankNameField_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Name must not be empty");
-    LabelDescriptor.create("", "description");
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> LabelDescriptor.create("", "description"));
+    assertThat(thrown).hasMessageThat().contains("Name must not be empty");
   }
 
   @Test
   public void testCreate_blankDescriptionField_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Description must not be empty");
-    LabelDescriptor.create("name", "");
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LabelDescriptor.create("name", ""));
+    assertThat(thrown).hasMessageThat().contains("Description must not be empty");
   }
 }

javatests/google/registry/monitoring/metrics/LinearFitterTest.java

@@ -15,65 +15,55 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 /** Unit tests for {@link LinearFitter}. */
 @RunWith(JUnit4.class)
 public class LinearFitterTest {
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testCreateLinearFitter_zeroNumIntervals_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("numFiniteIntervals must be greater than 0");
-
-    LinearFitter.create(0, 3.0, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(0, 3.0, 0.0));
+    assertThat(thrown).hasMessageThat().contains("numFiniteIntervals must be greater than 0");
   }
 
   @Test
   public void testCreateLinearFitter_negativeNumIntervals_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("numFiniteIntervals must be greater than 0");
-
-    LinearFitter.create(0, 3.0, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(0, 3.0, 0.0));
+    assertThat(thrown).hasMessageThat().contains("numFiniteIntervals must be greater than 0");
   }
 
   @Test
   public void testCreateLinearFitter_zeroWidth_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("width must be greater than 0");
-
-    LinearFitter.create(3, 0.0, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(3, 0.0, 0.0));
+    assertThat(thrown).hasMessageThat().contains("width must be greater than 0");
   }
 
   @Test
   public void testCreateLinearFitter_negativeWidth_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("width must be greater than 0");
-
-    LinearFitter.create(3, 0.0, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(3, 0.0, 0.0));
+    assertThat(thrown).hasMessageThat().contains("width must be greater than 0");
   }
 
   @Test
   public void testCreateLinearFitter_NaNWidth_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("width must be greater than 0");
-
-    LinearFitter.create(3, Double.NaN, 0.0);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(3, Double.NaN, 0.0));
+    assertThat(thrown).hasMessageThat().contains("width must be greater than 0");
   }
 
   @Test
   public void testCreateLinearFitter_NaNOffset_throwsException() throws Exception {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-
-    LinearFitter.create(3, 1.0, Double.NaN);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> LinearFitter.create(3, 1.0, Double.NaN));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/MetricRegistryImplTest.java

@@ -15,6 +15,7 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 import static org.mockito.Mockito.mock;
 
 import com.google.common.collect.ImmutableList;
@@ -22,9 +23,7 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.MetricSchema.Kind;
 import org.junit.After;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -36,9 +35,6 @@ import org.junit.runners.JUnit4;
  */
 @RunWith(JUnit4.class)
 public class MetricRegistryImplTest {
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   private final LabelDescriptor label =
       LabelDescriptor.create("test_labelname", "test_labeldescription");
 
@@ -162,8 +158,10 @@ public class MetricRegistryImplTest {
                 Boolean.class);
     MetricRegistryImpl.getDefault().registerMetric("/test/metric", testMetric);
 
-    thrown.expect(IllegalStateException.class);
-    thrown.expectMessage("Duplicate metric of same name");
-    MetricRegistryImpl.getDefault().registerMetric("/test/metric", testMetric);
+    IllegalStateException thrown =
+        expectThrows(
+            IllegalStateException.class,
+            () -> MetricRegistryImpl.getDefault().registerMetric("/test/metric", testMetric));
+    assertThat(thrown).hasMessageThat().contains("Duplicate metric of same name");
   }
 }

javatests/google/registry/monitoring/metrics/MetricSchemaTest.java

@@ -14,11 +14,12 @@
 
 package google.registry.monitoring.metrics;
 
+import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
+
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.MetricSchema.Kind;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -26,37 +27,59 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class MetricSchemaTest {
 
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testCreate_blankNameField_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Name must not be blank");
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class,
+            () ->
                 MetricSchema.create(
-        "", "description", "valueDisplayName", Kind.GAUGE, ImmutableSet.<LabelDescriptor>of());
+                    "",
+                    "description",
+                    "valueDisplayName",
+                    Kind.GAUGE,
+                    ImmutableSet.<LabelDescriptor>of()));
+    assertThat(thrown).hasMessageThat().contains("Name must not be blank");
   }
 
   @Test
   public void testCreate_blankDescriptionField_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Description must not be blank");
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class,
+            () ->
                 MetricSchema.create(
-        "/name", "", "valueDisplayName", Kind.GAUGE, ImmutableSet.<LabelDescriptor>of());
+                    "/name",
+                    "",
+                    "valueDisplayName",
+                    Kind.GAUGE,
+                    ImmutableSet.<LabelDescriptor>of()));
+    assertThat(thrown).hasMessageThat().contains("Description must not be blank");
   }
 
   @Test
   public void testCreate_blankValueDisplayNameField_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Value Display Name must not be empty");
-    MetricSchema.create("/name", "description", "", Kind.GAUGE, ImmutableSet.<LabelDescriptor>of());
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class,
+            () ->
+                MetricSchema.create(
+                    "/name", "description", "", Kind.GAUGE, ImmutableSet.<LabelDescriptor>of()));
+    assertThat(thrown).hasMessageThat().contains("Value Display Name must not be empty");
   }
 
   @Test
   public void testCreate_nakedNames_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Name must be URL-like and start with a '/'");
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class,
+            () ->
                 MetricSchema.create(
-        "foo", "description", "valueDisplayName", Kind.GAUGE, ImmutableSet.<LabelDescriptor>of());
+                    "foo",
+                    "description",
+                    "valueDisplayName",
+                    Kind.GAUGE,
+                    ImmutableSet.<LabelDescriptor>of()));
+    assertThat(thrown).hasMessageThat().contains("Name must be URL-like and start with a '/'");
   }
 }

javatests/google/registry/monitoring/metrics/MutableDistributionTest.java

@@ -15,14 +15,13 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableRangeMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Range;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -31,9 +30,6 @@ import org.junit.runners.JUnit4;
 public class MutableDistributionTest {
 
   private MutableDistribution distribution;
-
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   @Before
   public void setUp() throws Exception {
     distribution = new MutableDistribution(CustomFitter.create(ImmutableSet.of(3.0, 5.0)));
@@ -125,30 +121,34 @@ public class MutableDistributionTest {
 
   @Test
   public void testAdd_negativeZero_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-    distribution.add(Double.longBitsToDouble(0x80000000));
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class,
+            () -> distribution.add(Double.longBitsToDouble(0x80000000)));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test
   public void testAdd_NaN_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-    distribution.add(Double.NaN);
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> distribution.add(Double.NaN));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test
   public void testAdd_positiveInfinity_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-    distribution.add(Double.POSITIVE_INFINITY);
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> distribution.add(Double.POSITIVE_INFINITY));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test
   public void testAdd_negativeInfinity_throwsException() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("value must be finite, not NaN, and not -0.0");
-    distribution.add(Double.NEGATIVE_INFINITY);
+    IllegalArgumentException thrown =
+        expectThrows(
+            IllegalArgumentException.class, () -> distribution.add(Double.NEGATIVE_INFINITY));
+    assertThat(thrown).hasMessageThat().contains("value must be finite, not NaN, and not -0.0");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/StoredMetricTest.java

@@ -15,13 +15,12 @@
 package google.registry.monitoring.metrics;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import org.joda.time.Instant;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -29,9 +28,6 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class StoredMetricTest {
 
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void testGetCardinality_reflectsCurrentCardinality() {
     StoredMetric<Boolean> smallMetric =
@@ -68,11 +64,12 @@ public class StoredMetricTest {
                 LabelDescriptor.create("label1", "bar"), LabelDescriptor.create("label2", "bar")),
             Boolean.class);
 
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage(
+    IllegalArgumentException thrown =
+        expectThrows(IllegalArgumentException.class, () -> dimensionalMetric.set(true, "foo"));
+    assertThat(thrown)
+        .hasMessageThat()
+        .contains(
             "The count of labelValues must be equal to the underlying Metric's count of labels.");
-
-    dimensionalMetric.set(true, "foo");
   }
 
   @Test

javatests/google/registry/monitoring/metrics/contrib/BUILD

@@ -13,7 +13,7 @@ java_library(
     deps = [
         "//java/google/registry/monitoring/metrics",
         "//java/google/registry/monitoring/metrics/contrib",
-        "//javatests/google/registry/testing",
+        "//javatests/google/registry/monitoring/metrics",
         "@com_google_guava",
         "@com_google_truth",
         "@com_google_truth_extensions_truth_java8_extension",

javatests/google/registry/monitoring/metrics/contrib/DistributionMetricSubjectTest.java

@@ -15,8 +15,8 @@
 package google.registry.monitoring.metrics.contrib;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 import static google.registry.monitoring.metrics.contrib.DistributionMetricSubject.assertThat;
-import static google.registry.testing.JUnitBackports.expectThrows;
 
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.EventMetric;

javatests/google/registry/monitoring/metrics/contrib/LongMetricSubjectTest.java

@@ -15,8 +15,8 @@
 package google.registry.monitoring.metrics.contrib;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.expectThrows;
 import static google.registry.monitoring.metrics.contrib.LongMetricSubject.assertThat;
-import static org.junit.Assert.fail;
 
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.IncrementableMetric;
@@ -52,17 +52,15 @@ public class LongMetricSubjectTest {
 
   @Test
   public void testWrongNumberOfLabels_fails() {
-    try {
-      assertThat(metric).hasValueForLabels(1, "Domestic");
-      fail("Expected assertion error");
-    } catch (AssertionError e) {
+    AssertionError e =
+        expectThrows(
+            AssertionError.class, () -> assertThat(metric).hasValueForLabels(1, "Domestic"));
     assertThat(e)
         .hasMessageThat()
         .isEqualTo(
             "Not true that </test/incrementable/sheep> has a value for labels <Domestic>."
                 + " It has labeled values <[Bighorn:Blue => 2, Domestic:Green => 1]>");
   }
-  }
 
   @Test
   public void testDoesNotHaveWrongNumberOfLabels_succeeds() {
@@ -96,43 +94,44 @@ public class LongMetricSubjectTest {
 
   @Test
   public void testDoesNotHaveValueForLabels_failure() {
-    try {
-      assertThat(metric).doesNotHaveAnyValueForLabels("Domestic", "Green");
-      fail("Expected assertion error");
-    } catch (AssertionError e) {
+    AssertionError e =
+        expectThrows(
+            AssertionError.class,
+            () -> assertThat(metric).doesNotHaveAnyValueForLabels("Domestic", "Green"));
     assertThat(e)
         .hasMessageThat()
         .isEqualTo(
             "Not true that </test/incrementable/sheep> has no value for labels <Domestic:Green>."
                 + " It has a value of <1>");
   }
-  }
 
   @Test
   public void testWrongValue_failure() {
-    try {
-      assertThat(metric).hasValueForLabels(2, "Domestic", "Green");
-      fail("Expected assertion error");
-    } catch (AssertionError e) {
+    AssertionError e =
+        expectThrows(
+            AssertionError.class,
+            () -> assertThat(metric).hasValueForLabels(2, "Domestic", "Green"));
     assertThat(e)
         .hasMessageThat()
         .isEqualTo(
             "Not true that </test/incrementable/sheep> has a value of 2"
                 + " for labels <Domestic:Green>. It has a value of <1>");
   }
-  }
 
   @Test
   public void testUnexpectedValue_failure() {
-    try {
-      assertThat(metric).hasValueForLabels(1, "Domestic", "Green").and().hasNoOtherValues();
-      fail("Expected assertion error");
-    } catch (AssertionError e) {
+    AssertionError e =
+        expectThrows(
+            AssertionError.class,
+            () ->
+                assertThat(metric)
+                    .hasValueForLabels(1, "Domestic", "Green")
+                    .and()
+                    .hasNoOtherValues());
     assertThat(e)
         .hasMessageThat()
         .isEqualTo(
             "Not true that </test/incrementable/sheep> has <no other nondefault values>."
                 + " It has labeled values <[Bighorn:Blue => 2, Domestic:Green => 1]>");
   }
-  }
 }

javatests/google/registry/monitoring/metrics/stackdriver/BUILD

@@ -13,6 +13,7 @@ java_library(
     deps = [
         "//java/google/registry/monitoring/metrics",
         "//java/google/registry/monitoring/metrics/stackdriver",
+        "//javatests/google/registry/monitoring/metrics",
         "@com_google_api_client",
         "@com_google_apis_google_api_services_monitoring",
         "@com_google_guava",

javatests/google/registry/monitoring/metrics/stackdriver/StackdriverWriterTest.java

@@ -15,8 +15,8 @@
 package google.registry.monitoring.metrics.stackdriver;
 
 import static com.google.common.truth.Truth.assertThat;
+import static google.registry.monitoring.metrics.JUnitBackports.assertThrows;
 import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.junit.Assert.fail;
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.never;
@@ -184,10 +184,7 @@ public class StackdriverWriterTest {
         new StackdriverWriter(client, PROJECT, MONITORED_RESOURCE, MAX_QPS, MAX_POINTS_PER_REQUEST);
 
     for (MetricPoint<?> point : metric.getTimestampedValues()) {
-      try {
-        writer.write(point);
-        fail("expected IllegalArgumentException");
-      } catch (IOException expected) {}
+      assertThrows(IOException.class, () -> writer.write(point));
     }
   }
 
@@ -272,13 +269,9 @@ public class StackdriverWriterTest {
     StackdriverWriter writer =
         new StackdriverWriter(client, PROJECT, MONITORED_RESOURCE, MAX_QPS, MAX_POINTS_PER_REQUEST);
 
-    try {
-      writer.registerMetric(metric);
-      fail("Expected GoogleJsonResponseException");
-    } catch (GoogleJsonResponseException expected) {
+    assertThrows(GoogleJsonResponseException.class, () -> writer.registerMetric(metric));
     assertThat(exception.getStatusCode()).isEqualTo(404);
   }
-  }
 
   @Test
   public void getEncodedTimeSeries_nullLabels_encodes() throws Exception {