feat!: return boolean success value from setGlobalXXX methods

src/api/context.ts

@@ -44,13 +44,12 @@ export class ContextAPI {
   }
 
   /**
-   * Set the current context manager. Returns the initialized context manager
+   * Set the current context manager.
+   *
+   * @returns true if the context manager was successfully registered, else false
    */
-  public setGlobalContextManager(
-    contextManager: ContextManager
-  ): ContextManager {
-    registerGlobal(API_NAME, contextManager);
-    return contextManager;
+  public setGlobalContextManager(contextManager: ContextManager): boolean {
+    return registerGlobal(API_NAME, contextManager);
   }
 
   /**

src/api/diag.ts

@@ -76,10 +76,14 @@ export class DiagAPI implements DiagLogger {
           'Cannot use diag as the logger for itself. Please use a DiagLogger implementation like ConsoleDiagLogger or a custom implementation'
         );
         self.error(err.stack ?? err.message);
-        return;
+        return false;
       }
 
-      registerGlobal('diag', createLogLevelDiagLogger(logLevel, logger), true);
+      return registerGlobal(
+        'diag',
+        createLogLevelDiagLogger(logLevel, logger),
+        true
+      );
     };
 
     self.disable = () => {
@@ -99,9 +103,9 @@ export class DiagAPI implements DiagLogger {
    *
    * @param logger - [Optional] The DiagLogger instance to set as the default logger.
    * @param logLevel - [Optional] The DiagLogLevel used to filter logs sent to the logger. If not provided it will default to INFO.
-   * @returns The previously registered DiagLogger
+   * @returns true if the logger was successfully registered, else false
    */
-  public setLogger!: (logger: DiagLogger, logLevel?: DiagLogLevel) => void;
+  public setLogger!: (logger: DiagLogger, logLevel?: DiagLogLevel) => boolean;
 
   // DiagLogger implementation
   public verbose!: DiagLogFunction;

src/api/propagation.ts

@@ -50,11 +50,12 @@ export class PropagationAPI {
   }
 
   /**
-   * Set the current propagator. Returns the initialized propagator
+   * Set the current propagator.
+   *
+   * @returns true if the propagator was successfully registered, else false
    */
-  public setGlobalPropagator(propagator: TextMapPropagator): TextMapPropagator {
-    registerGlobal(API_NAME, propagator);
-    return propagator;
+  public setGlobalPropagator(propagator: TextMapPropagator): boolean {
+    return registerGlobal(API_NAME, propagator);
   }
 
   /**

src/api/trace.ts

@@ -47,12 +47,13 @@ export class TraceAPI {
   }
 
   /**
-   * Set the current global tracer. Returns the initialized global tracer provider
+   * Set the current global tracer.
+   *
+   * @returns true if the tracer provider was successfully registered, else false
    */
-  public setGlobalTracerProvider(provider: TracerProvider): TracerProvider {
+  public setGlobalTracerProvider(provider: TracerProvider): boolean {
     this._proxyTracerProvider.setDelegate(provider);
-    registerGlobal(API_NAME, this._proxyTracerProvider);
-    return this._proxyTracerProvider;
+    return registerGlobal(API_NAME, this._proxyTracerProvider);
   }
 
   /**

src/internal/global-utils.ts

@@ -34,7 +34,7 @@ export function registerGlobal<Type extends keyof OTelGlobalAPI>(
   type: Type,
   instance: OTelGlobalAPI[Type],
   allowOverride = false
-): void {
+): boolean {
   _global[GLOBAL_OPENTELEMETRY_API_KEY] = _global[
     GLOBAL_OPENTELEMETRY_API_KEY
   ] ?? {
@@ -48,7 +48,7 @@ export function registerGlobal<Type extends keyof OTelGlobalAPI>(
       `@opentelemetry/api: Attempted duplicate registration of API: ${type}`
     );
     diag.error(err.stack || err.message);
-    return;
+    return false;
   }
 
   if (api.version !== VERSION) {
@@ -57,10 +57,11 @@ export function registerGlobal<Type extends keyof OTelGlobalAPI>(
       '@opentelemetry/api: All API registration versions must match'
     );
     diag.error(err.stack || err.message);
-    return;
+    return false;
   }
 
   api[type] = instance;
+  return true;
 }
 
 export function getGlobal<Type extends keyof OTelGlobalAPI>(