feat: add config.disableUntracedModulesWarn (#1070)

Author: kjin

src/config.ts

@@ -94,6 +94,12 @@ export interface Config {
    */
   logLevel?: number;
 
+  /**
+   * If set to true, prevents a warning from being emitted if modules are
+   * required before the Trace Agent.
+   */
+  disableUntracedModulesWarning?: boolean;
+
   /**
    * Whether to enable to Trace Agent or not.
    * Once enabled, the Trace Agent may not be disabled.
@@ -312,6 +318,7 @@ export interface Config {
  */
 export const defaultConfig = {
   logLevel: 1,
+  disableUntracedModulesWarning: false,
   enabled: true,
   enhancedDatabaseReporting: false,
   rootSpanNameOverride: (name: string) => name,

src/index.ts

@@ -114,6 +114,7 @@ function initConfig(userConfig: Forceable<Config>): TopLevelConfig {
 
   return {
     [FORCE_NEW]: forceNew,
+    disableUntracedModulesWarning: mergedConfig.disableUntracedModulesWarning,
     enabled: mergedConfig.enabled,
     logLevel: lastOf(
       mergedConfig.logLevel,
@@ -230,7 +231,12 @@ export function start(config?: Config): PluginTypes.Tracer {
       throw new Error('Cannot call start on an already created agent.');
     }
     tracing.enable();
-    tracing.logModulesLoadedBeforeTrace(filesLoadedBeforeTrace);
+    if (
+      normalizedConfig.enabled &&
+      !normalizedConfig.disableUntracedModulesWarning
+    ) {
+      tracing.logModulesLoadedBeforeTrace(filesLoadedBeforeTrace);
+    }
     return traceAgent;
   } finally {
     // Stop storing these entries in memory

src/tracing.ts

@@ -30,6 +30,7 @@ export type TopLevelConfig =
   | Forceable<{
       enabled: boolean;
       logLevel: number;
+      disableUntracedModulesWarning: boolean;
       clsConfig: Forceable<TraceCLSConfig>;
       writerConfig: Forceable<TraceWriterConfig>;
       pluginLoaderConfig: Forceable<PluginLoaderConfig>;

test/test-modules-loaded-before-agent.ts

@@ -22,8 +22,10 @@ import * as log from '../src/logger';
 import {TestLogger} from './logger';
 import * as testTraceModule from './trace';
 
+const UNTRACED_LOGS_WARNING = /StackdriverTracer#start.*modules.*loaded.*before.*trace agent.*: \[.*shimmer.*\]/;
+
 describe('modules loaded before agent', () => {
-  let logger: CaptureTestLogger;
+  let logger: CaptureTestLogger | null = null;
 
   class CaptureTestLogger extends TestLogger {
     constructor() {
@@ -40,14 +42,25 @@ describe('modules loaded before agent', () => {
     shimmer.unwrap(log, 'Logger');
   });
 
+  afterEach(() => {
+    logger = null;
+  });
+
   it('should log if modules were loaded before agent', () => {
     testTraceModule.start();
+    assert.ok(logger);
     assert.strictEqual(
-      logger.getNumLogsWith(
-        'warn',
-        /StackdriverTracer#start.*modules.*loaded.*before.*trace agent.*: \[.*shimmer.*\]/
-      ),
+      logger!.getNumLogsWith('warn', UNTRACED_LOGS_WARNING),
       1
     );
   });
+
+  it('should not log if disableUntracedModulesWarning is set to true', () => {
+    testTraceModule.start({disableUntracedModulesWarning: true});
+    assert.ok(logger);
+    assert.strictEqual(
+      logger!.getNumLogsWith('warn', UNTRACED_LOGS_WARNING),
+      0
+    );
+  });
 });