fix: log uncaught exception in root logger only

src/logger.ts

@@ -654,11 +654,15 @@ export class Logger {
   }
 
   private uncaughtExceptionHandler = (err: Error) => {
-    // log the exception
-    // FIXME: good chance this won't be logged because
-    // process.exit was called before this is logged
-    // https://github.com/trentm/node-bunyan/issues/95
-    this.fatal(err);
+    // W-7558552
+    // Only log uncaught exceptions in root logger
+    if (this === Logger.rootLogger) {
+      // log the exception
+      // FIXME: good chance this won't be logged because
+      // process.exit was called before this is logged
+      // https://github.com/trentm/node-bunyan/issues/95
+      this.fatal(err);
+    }
   };
 
   private exitHandler = () => {

test/unit/loggerTest.ts

@@ -157,6 +157,17 @@ describe('Logger', () => {
       expect(Logger.root['called']).to.be.true;
       expect(rootLogger.addLogFileStream['called']).to.be.false;
     });
+
+    it('should log uncaught exception in root logger', async () => {
+      process.env.SFDX_ENV = 'dev';
+
+      $$.SANDBOX.stub(Logger.prototype, 'fatal');
+      const rootLogger = await Logger.root();
+
+      // @ts-ignore
+      Logger.lifecycle.emit('uncaughtException', 'testException');
+      expect(rootLogger.fatal['called']).to.be.true;
+    });
   });
 
   describe('child', () => {
@@ -166,6 +177,18 @@ describe('Logger', () => {
       expect(childLogger).to.be.instanceof(Logger);
       expect(childLogger.getName()).to.equal(childLoggerName);
     });
+
+    it('should not log uncaught exception in child logger', async () => {
+      process.env.SFDX_ENV = 'dev';
+
+      $$.SANDBOX.stub(Logger.prototype, 'fatal');
+      const childLoggerName = 'myChildLogger';
+      const childLogger = await Logger.child(childLoggerName);
+
+      // @ts-ignore
+      Logger.lifecycle.emit('uncaughtException', 'testException');
+      expect(childLogger.fatal['called']).to.be.true;
+    });
   });
 
   describe('debugCallback', () => {