Filter partial update fix

[louis-lau]

Calling {put} /users/:user/filters/:filter without either query or action produced an error similar to these.

{
  "error": "Cannot use 'in' operator to search for 'seen' in undefined"
}

Wrapped the existing logic in some checks for query and action. Also changed error: 'No changes' to success: true. IMO if you ask for no changes, and then no changes are performed, that's a success.

The github diff doesn't seem to like showing indentation changes very clearly it seems. 😉

[andris9]

That was one confusing diff. Now that I look at the code I see the mistake. I thought that by applying .default({}) to the query object in the input processing step would ensure that there is always a query object available but I was not using only the validation result but the original input as well. And the "no changes" error response had a specific reason but I don't remember what the reason was anymore, so I guess there is no reason.

[louis-lau]

Ahh, makes sense. Yeah not sure what's up with the diff hahaha, hiding whitespace changes helps. Cheers!