Allow empty global attributes from Supplier at startup

core/src/main/java/io/opentelemetry/android/config/OtelRumConfig.java

@@ -5,6 +5,8 @@
 
 package io.opentelemetry.android.config;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import io.opentelemetry.android.ScreenAttributesSpanProcessor;
 import io.opentelemetry.android.features.diskbuffering.DiskBufferingConfig;
 import io.opentelemetry.android.internal.services.network.CurrentNetworkProvider;
@@ -19,7 +21,8 @@
  * components.
  */
 public class OtelRumConfig {
-    private Supplier<Attributes> globalAttributesSupplier = Attributes::empty;
+
+    @Nullable private Supplier<Attributes> globalAttributesSupplier = null;
     private boolean includeNetworkAttributes = true;
     private boolean generateSdkInitializationEvents = true;
     private boolean includeScreenAttributes = true;
@@ -31,7 +34,10 @@ public class OtelRumConfig {
      * Configures the set of global attributes to emit with every span and event. Any existing
      * configured attributes will be dropped. Default = none.
      */
-    public OtelRumConfig setGlobalAttributes(Attributes attributes) {
+    public OtelRumConfig setGlobalAttributes(@Nullable Attributes attributes) {
+        if (attributes == null || attributes.isEmpty()) {
+            return this;
+        }
         return setGlobalAttributes(() -> attributes);
     }
 
@@ -41,12 +47,12 @@ public OtelRumConfig setGlobalAttributes(Supplier<Attributes> globalAttributesSu
     }
 
     public boolean hasGlobalAttributes() {
-        Attributes attributes = globalAttributesSupplier.get();
-        return attributes != null && !attributes.isEmpty();
+        return globalAttributesSupplier != null;
     }
 
+    @NonNull
     public Supplier<Attributes> getGlobalAttributesSupplier() {
-        return globalAttributesSupplier;
+        return globalAttributesSupplier == null ? Attributes::empty : globalAttributesSupplier;
     }
 
     /**

core/src/test/java/io/opentelemetry/android/config/OtelRumConfigTest.kt

@@ -0,0 +1,77 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.config
+
+import io.opentelemetry.api.common.AttributeKey.stringKey
+import io.opentelemetry.api.common.Attributes
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+import java.util.function.Supplier
+
+class OtelRumConfigTest {
+    @Test
+    fun `no global attributes by default`() {
+        val config = OtelRumConfig()
+        assertThat(config.hasGlobalAttributes()).isFalse()
+        assertThat(config.globalAttributesSupplier.get().isEmpty).isTrue()
+    }
+
+    @Test
+    fun `setting null Attributes does nothing`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes(null as Attributes?)
+        assertThat(config.hasGlobalAttributes()).isFalse()
+        assertThat(config.globalAttributesSupplier.get().isEmpty).isTrue()
+    }
+
+    @Test
+    fun `setting empty Attributes does nothing`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes(Attributes.empty())
+        assertThat(config.hasGlobalAttributes()).isFalse()
+        assertThat(config.globalAttributesSupplier.get().isEmpty).isTrue()
+    }
+
+    @Test
+    fun `can set some Attributes directly`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes(Attributes.of(stringKey("foo"), "bar"))
+        assertThat(config.hasGlobalAttributes()).isTrue()
+        assertThat(config.globalAttributesSupplier.get().get(stringKey("foo"))).isEqualTo("bar")
+    }
+
+    @Test
+    fun `setting a null attribute supplier does nothing`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes(null as Supplier<Attributes>?)
+        assertThat(config.hasGlobalAttributes()).isFalse()
+        assertThat(config.globalAttributesSupplier.get().isEmpty).isTrue()
+    }
+
+    @Test
+    fun `setting a Supplier that returns empty attributes is fine`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes { Attributes.empty() }
+        assertThat(config.hasGlobalAttributes()).isTrue() // It might return some Attributes later
+        assertThat(config.globalAttributesSupplier.get().isEmpty).isTrue()
+    }
+
+    @Test
+    fun `setting a Supplier that returns null attributes is fine`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes { null }
+        assertThat(config.hasGlobalAttributes()).isTrue() // It might return some Attributes later
+        assertThat(config.globalAttributesSupplier.get()).isNull()
+    }
+
+    @Test
+    fun `can supply global attributes with a supplier`() {
+        val config = OtelRumConfig()
+        config.setGlobalAttributes { Attributes.of(stringKey("foo"), "bar") }
+        assertThat(config.hasGlobalAttributes()).isTrue()
+        assertThat(config.globalAttributesSupplier.get().get(stringKey("foo"))).isEqualTo("bar")
+    }
+}

instrumentation/httpurlconnection/library/src/main/java/io/opentelemetry/instrumentation/library/httpurlconnection/HttpUrlInstrumentation.java

@@ -20,7 +20,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import org.jetbrains.annotations.NotNull;
 
 /** Instrumentation for HttpURLConnection requests. */
 @AutoService(AndroidInstrumentation.class)
@@ -137,7 +136,7 @@ public boolean emitExperimentalHttpClientMetrics() {
     }
 
     @Override
-    public void install(@NotNull InstallationContext ctx) {
+    public void install(@NonNull InstallationContext ctx) {
         HttpUrlConnectionSingletons.configure(this, ctx.getOpenTelemetry());
     }
 

instrumentation/okhttp3/library/src/main/java/io/opentelemetry/instrumentation/library/okhttp/v3_0/OkHttpInstrumentation.java

@@ -21,7 +21,6 @@
 import java.util.Set;
 import okhttp3.Interceptor;
 import okhttp3.Response;
-import org.jetbrains.annotations.NotNull;
 
 /** Instrumentation for okhttp requests. */
 @AutoService(AndroidInstrumentation.class)
@@ -139,7 +138,7 @@ public boolean emitExperimentalHttpClientTelemetry() {
     }
 
     @Override
-    public void install(@NotNull InstallationContext ctx) {
+    public void install(@NonNull InstallationContext ctx) {
         OkHttp3Singletons.configure(this, ctx.getOpenTelemetry());
     }