Addons-server: Localize all error messages in API responses

[kumar303]

Describe the problem and steps to reproduce it:

The addons-frontend app makes API requests with a language setting in hopes that we receive localized responses.

What happened?

As discovered via https://github.com/mozilla/addons-server/issues/4652, some error messages such as this one are not marked for localization.

Example request:
POST http://olympia.dev/api/v3/addons/addon/sound-control/reviews/?lang=de
This could result in:
{"non_field_errors":["An add-on author can not leave a review on its own add-on."]}

What did you expect to happen?

Can we get these strings localized? It should be possible with a lazy gettext call.

[kumar303]

Here is my rationale for why I think the API should be responsible for localizing error messages: https://github.com/mozilla/addons-frontend/issues/1775#issuecomment-278817291

[diox]

Part of the reason why I didn't do it is that I made up the error messages myself (sometimes writing APIs that we didn't need yet) and I'm not a native english speaker. If we can agree on the wording then yes, it's trivial to localize the messages.

[diox]

Can anyone confirm those strings in the ratings API are good, and if not, suggest better ones ?

• Can not reply to a review that is already a reply.
• Can not change version once the review has been created.
• Version does not exist on this add-on or is not public.
• An add-on author can not leave a review on its own add-on.
• The same user can not leave a review on the same more than once.

[tofumatt]

Slight tweaks:

• Cannot reply to a review that is already a reply.
• Cannot change the version of the add-on reviewed once the review has been created.
• This version of the add-on doesn't exist or isn't public.
• You can't leave a review on your own add-on.
• You can't leave more than one review for the same version of an add-on.

(The second one I was a bit unclear on but I think that's what it means.)

[diox]

The second one should not be exposed to the user through the frontend, but yes, you got it.

Do you think we should conjugate the first 3 ? Like, "You can't reply to a review...".

[tofumatt]

Do you think we should conjugate the first 3 ? Like, "You can't reply to a review...".

Yes, actually! Good call. The third one should change a bit for that: "You can't review this version of this add-on; it doesn't exist or isn't public."

[kumar303]

Yeah, I agree on the conjugation. All messages should be complete sentences.

I wouldn't worry too much about getting them perfect, we can make tweaks to them as people (like QA, etc) review the site. I know that it's a little more work for localizers that way but I think they are already aware that we are actively developing a new version of the site.

[kumar303]

Would it also help to mark all unlocalized strings with _to_localize('The yet to be localized text')? (Or some no-op function like that.) We did that before so we could easily grep to find all strings.

[diox]

Might as well localize the strings directly :) I'll submit a PR shortly for the strings I've found.