Generally, when we see discussion of English-Spanish code-switching, the discussion itself is often times in English. Evidence of this can be seen in the colloquial name for this phenomenon: Spanglish.
Since code-switching is the meeting of two languages, there should obviously be two discussions–one in each language. Check out this article from El Mundo, one of Spain’s newspapers, which discusses it from the Spanish language point of view. At one point they even use a different name for it: ingañol.