Unrelated to this PR specifically, but I was sure that we must have a space before … symbol.

Also unrelated, but there was a 4th undefined argument to these functions, usually app, string, params, undefined, { escape: false}
Should we add a rule to warn on it?

Also unrelated, but there was a 4th undefined argument to these functions, usually app, string, params, undefined, { escape: false}

Do you mean t(app, text, params, number, options) which is deprecated in favor of t(app, params, options) ?
I do not think we need to warn on every deprecated of a library we maintain, before you upgrade dependencies you should check the release notes and adjust your code. In this case l10n get rather few updates.

Unrelated to this PR specifically, but I was sure that we must have a space before … symbol.

I think only if its within a sentence representing omitted text, when its on a single word there should be no space.

If you trying to shorten words as i18n, or cut by the max length - it's an ellipsized text, which shouldn't be spaced

Otherwise it has different meanin. Ellipsis should IMO be spaced from both sides, if it represents:

• omitted words
• pause / waiting

If you trying to shorten words as i18n, or cut by the max length - it's an ellipsized text, which shouldn't be spaced

Which is never the case for l10n string