don't throw class cast exception when we have a noop tracer, meter, logger

api/all/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
   id("otel.java-conventions")
   id("otel.publish-conventions")
+  id("java-test-fixtures")
 
   id("otel.jmh-conventions")
   id("otel.animalsniffer-conventions")
@@ -17,6 +18,10 @@ dependencies {
 
   testImplementation("edu.berkeley.cs.jqf:jqf-fuzz")
   testImplementation("com.google.guava:guava-testlib")
+  testFixturesApi(project(":testing-internal"))
+  testFixturesApi("junit:junit")
+  testFixturesApi("org.assertj:assertj-core")
+  testFixturesApi("org.mockito:mockito-core")
 }
 
 tasks.test {

api/all/src/main/java/io/opentelemetry/api/internal/IncubatingUtil.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.internal;
+
+import java.lang.reflect.Method;
+
+/**
+ * Incubating utilities.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public class IncubatingUtil {
+  private IncubatingUtil() {}
+
+  @SuppressWarnings("unchecked")
+  public static <T> T incubatingApiIfAvailable(T stableApi, String incubatingClassName) {
+    try {
+      Class<?> incubatingClass = Class.forName(incubatingClassName);
+      Method getInstance = incubatingClass.getDeclaredMethod("getNoop");
+      return (T) getInstance.invoke(null);
+    } catch (Exception e) {
+      return stableApi;
+    }
+  }
+}

api/all/src/main/java/io/opentelemetry/api/logs/LoggerProvider.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.api.logs;
 
+import io.opentelemetry.api.internal.IncubatingUtil;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -43,6 +44,8 @@ default Logger get(String instrumentationScopeName) {
 
   /** Returns a no-op {@link LoggerProvider} which provides Loggers which do not record or emit. */
   static LoggerProvider noop() {
-    return DefaultLoggerProvider.getInstance();
+    return IncubatingUtil.incubatingApiIfAvailable(
+        DefaultLoggerProvider.getInstance(),
+        "io.opentelemetry.api.incubator.logs.ExtendedDefaultLoggerProvider");
   }
 }

api/all/src/main/java/io/opentelemetry/api/metrics/DefaultMeterProvider.java

@@ -5,14 +5,19 @@
 
 package io.opentelemetry.api.metrics;
 
+import io.opentelemetry.api.internal.IncubatingUtil;
+
 /** A {@link MeterProvider} that does nothing. */
 class DefaultMeterProvider implements MeterProvider {
   @Override
   public MeterBuilder meterBuilder(String instrumentationScopeName) {
     return BUILDER_INSTANCE;
   }
 
-  private static final DefaultMeterProvider INSTANCE = new DefaultMeterProvider();
+  private static final MeterProvider INSTANCE =
+      IncubatingUtil.incubatingApiIfAvailable(
+          new DefaultMeterProvider(),
+          "io.opentelemetry.api.incubator.metrics.ExtendedDefaultMeterProvider");
   private static final MeterBuilder BUILDER_INSTANCE = new NoopMeterBuilder();
 
   static MeterProvider getInstance() {

api/all/src/main/java/io/opentelemetry/api/trace/DefaultTracerProvider.java

@@ -5,12 +5,16 @@
 
 package io.opentelemetry.api.trace;
 
+import io.opentelemetry.api.internal.IncubatingUtil;
 import javax.annotation.concurrent.ThreadSafe;
 
 @ThreadSafe
 class DefaultTracerProvider implements TracerProvider {
 
-  private static final TracerProvider INSTANCE = new DefaultTracerProvider();
+  private static final TracerProvider INSTANCE =
+      IncubatingUtil.incubatingApiIfAvailable(
+          new DefaultTracerProvider(),
+          "io.opentelemetry.api.incubator.trace.ExtendedDefaultTracerProvider");
 
   static TracerProvider getInstance() {
     return INSTANCE;

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

@@ -5,100 +5,24 @@
 
 package io.opentelemetry.api;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.mockito.Mockito.mock;
-
 import io.opentelemetry.api.logs.LoggerProvider;
 import io.opentelemetry.api.metrics.MeterProvider;
 import io.opentelemetry.api.trace.TracerProvider;
-import io.opentelemetry.context.propagation.ContextPropagators;
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
-
-class OpenTelemetryTest {
-
-  @BeforeAll
-  static void beforeClass() {
-    GlobalOpenTelemetry.resetForTest();
-  }
-
-  @AfterEach
-  void after() {
-    GlobalOpenTelemetry.resetForTest();
-  }
-
-  @Test
-  void testDefault() {
-    assertThat(OpenTelemetry.noop().getTracerProvider()).isSameAs(TracerProvider.noop());
-    assertThat(OpenTelemetry.noop().getPropagators()).isSameAs(ContextPropagators.noop());
-    assertThat(OpenTelemetry.noop().getMeterProvider()).isSameAs(MeterProvider.noop());
-    assertThat(OpenTelemetry.noop().getLogsBridge()).isSameAs(LoggerProvider.noop());
-  }
 
-  @Test
-  void propagating() {
-    ContextPropagators contextPropagators = mock(ContextPropagators.class);
-    OpenTelemetry openTelemetry = OpenTelemetry.propagating(contextPropagators);
-
-    assertThat(openTelemetry.getTracerProvider()).isSameAs(TracerProvider.noop());
-    assertThat(openTelemetry.getMeterProvider()).isSameAs(MeterProvider.noop());
-    assertThat(openTelemetry.getLogsBridge()).isSameAs(LoggerProvider.noop());
-    assertThat(openTelemetry.getPropagators()).isSameAs(contextPropagators);
-  }
-
-  @Test
-  void testGlobalBeforeSet() {
-    assertThat(GlobalOpenTelemetry.getTracerProvider()).isSameAs(TracerProvider.noop());
-    assertThat(GlobalOpenTelemetry.getTracerProvider())
-        .isSameAs(GlobalOpenTelemetry.getTracerProvider());
-    assertThat(GlobalOpenTelemetry.getPropagators()).isSameAs(GlobalOpenTelemetry.getPropagators());
-  }
-
-  @Test
-  void independentNonGlobalPropagators() {
-    ContextPropagators propagators1 = mock(ContextPropagators.class);
-    OpenTelemetry otel1 = OpenTelemetry.propagating(propagators1);
-    ContextPropagators propagators2 = mock(ContextPropagators.class);
-    OpenTelemetry otel2 = OpenTelemetry.propagating(propagators2);
-
-    assertThat(otel1.getPropagators()).isSameAs(propagators1);
-    assertThat(otel2.getPropagators()).isSameAs(propagators2);
-  }
-
-  @Test
-  void setThenSet() {
-    setOpenTelemetry();
-    assertThatThrownBy(() -> GlobalOpenTelemetry.set(OpenTelemetry.noop()))
-        .isInstanceOf(IllegalStateException.class)
-        .hasMessageContaining("GlobalOpenTelemetry.set has already been called")
-        .hasStackTraceContaining("setOpenTelemetry");
-  }
-
-  @Test
-  void getThenSet() {
-    assertThat(getOpenTelemetry()).isInstanceOf(DefaultOpenTelemetry.class);
-    assertThatThrownBy(() -> GlobalOpenTelemetry.set(OpenTelemetry.noop()))
-        .isInstanceOf(IllegalStateException.class)
-        .hasMessageContaining("GlobalOpenTelemetry.set has already been called")
-        .hasStackTraceContaining("getOpenTelemetry");
-  }
+class OpenTelemetryTest extends AbstractOpenTelemetryTest {
 
-  @Test
-  void toString_noop_Valid() {
-    assertThat(OpenTelemetry.noop().toString())
-        .isEqualTo(
-            "DefaultOpenTelemetry{"
-                + "propagators=DefaultContextPropagators{textMapPropagator=NoopTextMapPropagator}"
-                + "}");
+  @Override
+  protected TracerProvider getTracerProvider() {
+    return TracerProvider.noop();
   }
 
-  private static void setOpenTelemetry() {
-    GlobalOpenTelemetry.set(OpenTelemetry.noop());
+  @Override
+  protected MeterProvider getMeterProvider() {
+    return MeterProvider.noop();
   }
 
-  private static OpenTelemetry getOpenTelemetry() {
-    return GlobalOpenTelemetry.get();
+  @Override
+  protected LoggerProvider getLoggerProvider() {
+    return LoggerProvider.noop();
   }
 }

api/all/src/test/java/io/opentelemetry/api/logs/DefaultLoggerTest.java

@@ -5,36 +5,15 @@
 
 package io.opentelemetry.api.logs;
 
-import static org.assertj.core.api.Assertions.assertThatCode;
+class DefaultLoggerTest extends AbstractDefaultLoggerTest {
 
-import io.opentelemetry.api.common.AttributeKey;
-import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.Value;
-import io.opentelemetry.context.Context;
-import java.time.Instant;
-import java.util.concurrent.TimeUnit;
-import org.junit.jupiter.api.Test;
-
-class DefaultLoggerTest {
+  @Override
+  protected LoggerProvider getLoggerProvider() {
+    return DefaultLoggerProvider.getInstance();
+  }
 
-  @Test
-  void buildAndEmit() {
-    assertThatCode(
-            () ->
-                DefaultLogger.getInstance()
-                    .logRecordBuilder()
-                    .setTimestamp(100, TimeUnit.SECONDS)
-                    .setTimestamp(Instant.now())
-                    .setObservedTimestamp(100, TimeUnit.SECONDS)
-                    .setObservedTimestamp(Instant.now())
-                    .setContext(Context.root())
-                    .setSeverity(Severity.DEBUG)
-                    .setSeverityText("debug")
-                    .setBody("body")
-                    .setBody(Value.of("body"))
-                    .setAttribute(AttributeKey.stringKey("key1"), "value1")
-                    .setAllAttributes(Attributes.builder().put("key2", "value2").build())
-                    .emit())
-        .doesNotThrowAnyException();
+  @Override
+  protected Logger getLogger() {
+    return DefaultLogger.getInstance();
   }
 }