Getting typescript to properly infer return type of action?

[sdellysse]

I've been away from Typescript for a few months and I'm trying to get back into the swing of things and this one is driving me mad. I have an action function that can return either json({ success: true }) or json({ success: false, errors, formData }). For some reason, TS is inferring the return type of action to be just Promise<TypedResponse<{ success: boolean; }>>. I'm not sure why the rest is getting tossed on the floor.

I have two Playground links, one where I attempt to get TS to infer the correct return type, and another where I have to tell it what the return type is. Am I doing something wrong here? This can't be as difficult as I'm making it out to be, is it?

Playground for what I'd like to work: https://www.typescriptlang.org/play?target=99#code/JYWwDg9gTgLgBAbzgQQMY2BAdgMQK5bqZbJQDmAzgDRwAqAnmAKYAmASkxZFhUzQFYVscAL5wAZlAgg4AIgACUJiGAAPALRQCAeiwQWTWQG4AUKEixEcAF6iJUmbOv7jJk01UX4qbBXjAKAGFfGCgAQ2AsGABRKCkoOABeOAAKJjjoAC44AgBrPQB3LBofHlCIqOy-KEiyAEokgD5EEzg4JRg8KCxU1ra4dPi4SL8wwiYIcThYoYAyWb622VLqiphZYZ7B6Dh5xbgYRgmp7agAOhXyyPhE27lq2o29-oGM88vw66S7j7W+utMIlM7k80G8ITgYSIwmSYQo9EIqTC5GyaAw2HwhHRJHIFAaiWaCD6lwk0BAABEwjAwkk4AB5ABG-CY6DOkmk0SiNU4KTCBQi8GRZDOSgAjnhODA2WTKdSUnUAW42iSKKgABbKMI4GVUmnJaxnCBMlkwFJEl4QMDZA0AG2AMHSYRtKVkYRYLAA+jAIB7+fa7X5ZHUqPtNcAbdazg8sGR5WdQqA4yosCkAIw0WQccXAJQsINnMPO4N9ESK4kQ8RkgBqTuALCpxFpqo1IC1OupUbC4iYAAVkbwUpWoBTdWW2sApikAIRDkA1u317FRvCoVCcPEtF4dLo9QTYM37NoUFdrigUbLiJ28EMvNqz2VhG+307n0nD+d1hvYAtvNk2qkOimxYvKWphtCI5ZlG+MjJLOH6LsQZyLmEwJtKE9Cbv02jaJCfrwCwDIFqoLJ4A6cYUKKNoAAb7Nh-QjOk-hRBAwxnHhAYwBQaStuGNBUnUtE4W0ABuToSlxAAkCCzgWPE2iINCFPKAkvHRVGof027dHAe4puat7Hqu67ZKEEpPuBirgXAqBUuqqSnA0+njpOATBGUnxRDM0BpG8GZ4KKHoesAgXsQEnGBYWQaOYe7RMJ02m6Qet79IZp6vpeNrXjFd7to+2WvPEr5Ocl0FeVAr4ANqyNEcmQu6ShnsMFCQjaShuhhwgwBqcChX4ZyyAAuuZJXiMATA2iwZVFQp+UzcloH7BB+xdVIBQFdAYGiCYQImEAA

Playground with my explicit return type workaround: https://www.typescriptlang.org/play?target=99#code/JYWwDg9gTgLgBAbzgQQMY2BAdgMQK5bqZbJQDmAzgDRwAqAnmAKYAmASkxZFhUzQFYVscAL5wAZlAgg4AIgACUJiGAAPALRQCAeiwQWTWQG4AUKEixEcAF6iJUmbOv7jJk01UX4qbBXjAKAGFfGCgAQ2AsGABRKCkoOABeOAAKJjjoAC44AgBrPQB3LBofHlCIqOy-KEiyAEokgD5EEzg4JRg8KCxU1ra4dPi4SL8wwiYIcThYoYAyWb622VLqiphZYZ7B6Dh5xbgYRgmp7agAOhXyyPhE27lq2o29-oGM88vw66S7j7W+utMIlMJkOzBQRGwACkhD1En0AD5WCh4VCoTgUbKhPBMUQIlovNrI1Ho7LiMIAG14pgJEmgIAAImEYGFshxOt0GMwADyg45wADyACN+Ex0GdJNJolEapxGtSCacMfiabSoCAZtAlaRwvQuQ8sGQ5fsXuJgExySwNVAlRwfFAWHrQrUaNqwrr9YajTSgfsfR4vHBLnAwhDYcGKPRCL02mFyNk0BhsPhCImSORqCY6tkAAoOAJMLmc1gcLi+AsJ4jQ7CNZqJZoIPpB8R0xnMpIC4WimDihxSp2cFJhAoReCxshnJQAR2xfnFLaZYRSdQBbjaQYoqAAFsowjh523ktYzhBO+gUg2XhAwNkj+TgDB0hSUrIwiwWAB9GAQd-D+93vyyHUVD7DuwDkjeZwekuZxOiA0EqFgKQAIw0LIHDTsASgsIBZygeSS7AW0Igro2ISqiAABqFLACwTLEO2G7biAu77mEkFhOITDZrGvApM2aqtmEJFtMAUwpAAhPxlHUbRqaQSiaIUBQDQXv0HRdD0gjYOexpwESilKmSlJ8LpUmCYRCpvIZdJUXesnELhbziuSTIPohQG+iuRGkWU5HtlJtk0XR2BnLJYTAm0oT0MqbTaNowa-vALCCrhqiingD7QRQk7kgABvscX9CM6T+FEEDDGciX-jAFBpMxYE0EydQFfFbQAG4UjOKQACQIFJuH1eSIg0IUS7NS8hW5RFalMOymkwjpNL6SSBxaCZLzEfKYioEyW6pKcKn7KJqQBMEZSfFEVppG8qF4JO77vsAD1VQENUPXhgGHTS6ndHAWmIapS0KStRm8BZNJmQu4OWfESqAyqUlWkqADasjRINwZvkoSnDBQwbkkor7RcIMDbnAL2zrIAC60MQ2aFpI9kCDDbpRG06IXn9CIq79KTUgFK88RbSYPpAA