fix: allow passing string, number, null for %o placeholder (#2372)

* fix: allow passing string, number, null for %o placeholder

* update tests

Author: rChaoz

pino.d.ts

@@ -326,7 +326,7 @@ declare namespace pino {
         : T extends 's'
             ? unknown
             : T extends 'j' | 'o' | 'O'
-            ? object
+            ? {} | null
             : never;
 
     type ParseLogFnArgs<

test/types/pino.test-d.ts

@@ -54,12 +54,19 @@ info('All primitive types %s %s %s %s %s %s %s', 'string', 123, true, BigInt(123
 declare const errorOrString: string | Error;
 info(errorOrString)
 
+// %o placeholder supports primitives too (except undefined)
+info('Boolean %o', true);
+info('Boolean %o', false);
+info('Number %o', 123);
+info('Number %o', 3.14);
+info('BigInt %o', BigInt(123));
+info('Null %o', null);
+info('Symbol %o', Symbol('test'));
+info('String %o', 'hello');
+
 // placeholder messages type errors
 expectError(info('The answer is %d', 'not a number'));
-expectError(info('The object is %o', 'not an object'));
-expectError(info('The object is %j', 'not a JSON'));
-expectError(info('The object is %O', 'not an object'));
-expectError(info('The answer is %d and the question is %s with %o', 42, { incorrect: 'order' }, 'unknown'));
+expectError(info('The answer is %d and the question is %s with %o', 'unknown', { incorrect: 'order' }, 42));
 expectError(info('Extra message %s', 'after placeholder', 'not allowed'));
 
 // object types with messages