fix(logger): correct persistentLogAttributes warning behavior (#4627)

Author: alex-karo

packages/logger/src/Logger.ts

@@ -1291,7 +1291,12 @@ class Logger extends Utility implements LoggerInterface {
       correlationIdSearchFn,
     } = options;
 
-    if (persistentLogAttributes && persistentKeys) {
+    if (
+      persistentLogAttributes &&
+      Object.keys(persistentLogAttributes).length > 0 &&
+      persistentKeys &&
+      Object.keys(persistentKeys).length > 0
+    ) {
       this.warn(
         'Both persistentLogAttributes and persistentKeys options were provided. Using persistentKeys as persistentLogAttributes is deprecated and will be removed in future releases'
       );

packages/logger/tests/unit/workingWithkeys.test.ts

@@ -622,6 +622,15 @@ describe('Working with keys', () => {
     );
   });
 
+  it('should pass persistentKeys to child with no warning', () => {
+    // Prepare
+    const logger = new Logger();
+    logger.createChild({ persistentKeys: { abc: 'xyz' } });
+
+    // Assess
+    expect(console.warn).toHaveBeenCalledTimes(0);
+  });
+
   it("doesn't overwrite standard keys when appending keys", () => {
     // Prepare
     const logger = new Logger();