Migrate tests to JUnit5

all/src/test/java/io/opentelemetry/InternalApiProtectionTest.java

@@ -21,16 +21,16 @@
 import com.tngtech.archunit.core.domain.JavaClasses;
 import com.tngtech.archunit.core.importer.ClassFileImporter;
 import com.tngtech.archunit.lang.syntax.elements.ClassesShouldConjunction;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-public class InternalApiProtectionTest {
+class InternalApiProtectionTest {
 
   private static final String OTEL_BASE_PACKAGE = "io.opentelemetry";
   private static final JavaClasses ALL_OTEL_CLASSES =
       new ClassFileImporter().importPackages(OTEL_BASE_PACKAGE);
 
   @Test
-  public void contrib_should_not_use_internal_api() {
+  void contrib_should_not_use_internal_api() {
     ClassesShouldConjunction contribRule =
         noClasses()
             .that()

api/src/test/java/io/opentelemetry/OpenTelemetryTest.java

@@ -17,7 +17,8 @@
 package io.opentelemetry;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.context.propagation.ContextPropagators;
@@ -54,34 +55,27 @@
 import java.io.Writer;
 import java.net.URL;
 import javax.annotation.Nullable;
-import org.junit.After;
-import org.junit.BeforeClass;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.ExpectedException;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
 
-@RunWith(JUnit4.class)
-public class OpenTelemetryTest {
+class OpenTelemetryTest {
 
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
-  @BeforeClass
-  public static void beforeClass() {
+  @BeforeAll
+  static void beforeClass() {
     OpenTelemetry.reset();
   }
 
-  @After
-  public void after() {
+  @AfterEach
+  void after() {
     OpenTelemetry.reset();
     System.clearProperty(TracerProviderFactory.class.getName());
     System.clearProperty(MeterProviderFactory.class.getName());
     System.clearProperty(CorrelationContextManagerFactory.class.getName());
   }
 
   @Test
-  public void testDefault() {
+  void testDefault() {
     assertThat(OpenTelemetry.getTracerProvider()).isInstanceOf(DefaultTracerProvider.class);
     assertThat(OpenTelemetry.getTracerProvider())
         .isSameInstanceAs(OpenTelemetry.getTracerProvider());
@@ -96,7 +90,7 @@ public void testDefault() {
   }
 
   @Test
-  public void testTracerLoadArbitrary() throws IOException {
+  void testTracerLoadArbitrary() throws IOException {
     File serviceFile =
         createService(
             TracerProviderFactory.class,
@@ -113,7 +107,7 @@ public void testTracerLoadArbitrary() throws IOException {
   }
 
   @Test
-  public void testTracerSystemProperty() throws IOException {
+  void testTracerSystemProperty() throws IOException {
     File serviceFile =
         createService(
             TracerProviderFactory.class,
@@ -130,14 +124,13 @@ public void testTracerSystemProperty() throws IOException {
   }
 
   @Test
-  public void testTracerNotFound() {
+  void testTracerNotFound() {
     System.setProperty(TracerProviderFactory.class.getName(), "io.does.not.exists");
-    thrown.expect(IllegalStateException.class);
-    OpenTelemetry.getTracer("testTracer");
+    assertThrows(IllegalStateException.class, () -> OpenTelemetry.getTracer("testTracer"));
   }
 
   @Test
-  public void testMeterLoadArbitrary() throws IOException {
+  void testMeterLoadArbitrary() throws IOException {
     File serviceFile =
         createService(
             MeterProviderFactory.class,
@@ -154,7 +147,7 @@ public void testMeterLoadArbitrary() throws IOException {
   }
 
   @Test
-  public void testMeterSystemProperty() throws IOException {
+  void testMeterSystemProperty() throws IOException {
     File serviceFile =
         createService(
             MeterProviderFactory.class,
@@ -171,14 +164,13 @@ public void testMeterSystemProperty() throws IOException {
   }
 
   @Test
-  public void testMeterNotFound() {
+  void testMeterNotFound() {
     System.setProperty(MeterProviderFactory.class.getName(), "io.does.not.exists");
-    thrown.expect(IllegalStateException.class);
-    OpenTelemetry.getMeterProvider();
+    assertThrows(IllegalStateException.class, () -> OpenTelemetry.getMeterProvider());
   }
 
   @Test
-  public void testCorrelationContextManagerLoadArbitrary() throws IOException {
+  void testCorrelationContextManagerLoadArbitrary() throws IOException {
     File serviceFile =
         createService(
             CorrelationContextManagerFactory.class,
@@ -197,7 +189,7 @@ public void testCorrelationContextManagerLoadArbitrary() throws IOException {
   }
 
   @Test
-  public void testCorrelationContextManagerSystemProperty() throws IOException {
+  void testCorrelationContextManagerSystemProperty() throws IOException {
     File serviceFile =
         createService(
             CorrelationContextManagerFactory.class,
@@ -217,23 +209,21 @@ public void testCorrelationContextManagerSystemProperty() throws IOException {
   }
 
   @Test
-  public void testCorrelationContextManagerNotFound() {
+  void testCorrelationContextManagerNotFound() {
     System.setProperty(CorrelationContextManagerFactory.class.getName(), "io.does.not.exists");
-    thrown.expect(IllegalStateException.class);
-    OpenTelemetry.getCorrelationContextManager();
+    assertThrows(IllegalStateException.class, () -> OpenTelemetry.getCorrelationContextManager());
   }
 
   @Test
-  public void testPropagatorsSet() {
+  void testPropagatorsSet() {
     ContextPropagators propagators = DefaultContextPropagators.builder().build();
     OpenTelemetry.setPropagators(propagators);
     assertThat(OpenTelemetry.getPropagators()).isEqualTo(propagators);
   }
 
   @Test
-  public void testPropagatorsSetNull() {
-    thrown.expect(NullPointerException.class);
-    OpenTelemetry.setPropagators(null);
+  void testPropagatorsSetNull() {
+    assertThrows(NullPointerException.class, () -> OpenTelemetry.setPropagators(null));
   }
 
   private static File createService(Class<?> service, Class<?>... impls) throws IOException {

api/src/test/java/io/opentelemetry/common/AttributeValueTest.java

@@ -19,16 +19,12 @@
 import static com.google.common.truth.Truth.assertThat;
 
 import com.google.common.testing.EqualsTester;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.Test;
 
-/** Unit tests for {@link AttributeValue}. */
-@RunWith(JUnit4.class)
-public class AttributeValueTest {
+class AttributeValueTest {
 
   @Test
-  public void attributeValue_EqualsAndHashCode() {
+  void attributeValue_EqualsAndHashCode() {
     EqualsTester tester = new EqualsTester();
     tester.addEqualityGroup(
         AttributeValue.stringAttributeValue("MyStringAttributeValue"),
@@ -65,7 +61,7 @@ public void attributeValue_EqualsAndHashCode() {
   }
 
   @Test
-  public void doNotCrashOnNull() {
+  void doNotCrashOnNull() {
     AttributeValue.stringAttributeValue(null);
     AttributeValue.arrayAttributeValue((String[]) null);
     AttributeValue.arrayAttributeValue((Boolean[]) null);
@@ -74,7 +70,7 @@ public void doNotCrashOnNull() {
   }
 
   @Test
-  public void attributeValue_ToString() {
+  void attributeValue_ToString() {
     AttributeValue attribute = AttributeValue.stringAttributeValue("MyStringAttributeValue");
     assertThat(attribute.toString()).contains("MyStringAttributeValue");
     attribute = AttributeValue.booleanAttributeValue(true);
@@ -100,7 +96,7 @@ public void attributeValue_ToString() {
   }
 
   @Test
-  public void arrayAttributeValue_nullValuesWithinArray() {
+  void arrayAttributeValue_nullValuesWithinArray() {
     AttributeValue attribute;
 
     attribute = AttributeValue.arrayAttributeValue("string", null, "", "string");

api/src/test/java/io/opentelemetry/common/AttributesTest.java

@@ -26,16 +26,13 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.ExpectedException;
+import org.junit.jupiter.api.Test;
 
 /** Unit tests for {@link Attributes}s. */
-public class AttributesTest {
-  @Rule public final ExpectedException thrown = ExpectedException.none();
+class AttributesTest {
 
   @Test
-  public void forEach() {
+  void forEach() {
     final Map<String, AttributeValue> entriesSeen = new HashMap<>();
 
     Attributes attributes =
@@ -50,7 +47,7 @@ public void forEach() {
   }
 
   @Test
-  public void forEach_singleAttribute() {
+  void forEach_singleAttribute() {
     final Map<String, AttributeValue> entriesSeen = new HashMap<>();
 
     Attributes attributes = Attributes.of("key", stringAttributeValue("value"));
@@ -59,15 +56,15 @@ public void forEach_singleAttribute() {
   }
 
   @Test
-  public void forEach_empty() {
+  void forEach_empty() {
     final AtomicBoolean sawSomething = new AtomicBoolean(false);
     Attributes emptyAttributes = Attributes.empty();
     emptyAttributes.forEach((key, value) -> sawSomething.set(true));
     assertThat(sawSomething.get()).isFalse();
   }
 
   @Test
-  public void orderIndependentEquality() {
+  void orderIndependentEquality() {
     Attributes one =
         Attributes.of(
             "key1", stringAttributeValue("value1"),
@@ -103,7 +100,7 @@ public void orderIndependentEquality() {
   }
 
   @Test
-  public void deduplication() {
+  void deduplication() {
     Attributes one =
         Attributes.of(
             "key1", stringAttributeValue("value1"),
@@ -114,15 +111,15 @@ public void deduplication() {
   }
 
   @Test
-  public void emptyAndNullKey() {
+  void emptyAndNullKey() {
     Attributes noAttributes =
         Attributes.of("", stringAttributeValue("empty"), null, stringAttributeValue("null"));
 
     assertThat(noAttributes.size()).isEqualTo(0);
   }
 
   @Test
-  public void builder() {
+  void builder() {
     Attributes attributes =
         Attributes.newBuilder()
             .setAttribute("string", "value1")
@@ -142,7 +139,7 @@ public void builder() {
   }
 
   @Test
-  public void builder_arrayTypes() {
+  void builder_arrayTypes() {
     Attributes attributes =
         Attributes.newBuilder()
             .setAttribute("string", "value1", "value2")
@@ -163,13 +160,13 @@ public void builder_arrayTypes() {
   }
 
   @Test
-  public void get_Null() {
+  void get_Null() {
     assertThat(Attributes.empty().get("foo")).isNull();
     assertThat(Attributes.of("key", stringAttributeValue("value")).get("foo")).isNull();
   }
 
   @Test
-  public void get() {
+  void get() {
     assertThat(Attributes.of("key", stringAttributeValue("value")).get("key"))
         .isEqualTo(stringAttributeValue("value"));
     assertThat(Attributes.of("key", stringAttributeValue("value")).get("value")).isNull();

api/src/test/java/io/opentelemetry/common/ImmutableKeyValuePairsTest.java

@@ -22,11 +22,12 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+
+class ImmutableKeyValuePairsTest {
 
-public class ImmutableKeyValuePairsTest {
   @Test
-  public void toStringIsCorrect() {
+  void toStringIsCorrect() {
     assertThat(new TestPairs(Collections.emptyList()).toString()).isEqualTo("{}");
     assertThat(new TestPairs(Arrays.asList("one", 55)).toString()).isEqualTo("{one=55}");
     assertThat(new TestPairs(Arrays.asList("one", 55, "two", "b")).toString())