Use of "thus (far)" with past perfect

Question

I am working overtime this week, and I have earned $200 extra thus far.
I was working overtime that week, and I had earned $200 extra thus far. (?)

Does the use of thus far require that the action is continuing to the present (i.e. Is it grammatical to use thus far with past perfect?)?

Answer 1

Well, let's look at the difference between the two sentences.

I'm working overtime this week, and I've earned $200 extra thus far.

The week is presumably not over yet, and already the speaker has earned $200 extra. Now let's imagine expressing this about last week or just any week in the past. The entire week is already over, so using a word that means "up to this point" is odd.

Instead, what you want to say is that there was a point last week (or some week in the past), by which you had earned $200 extra. So it becomes something like:

I was working overtime last/that week, and I had already earned $200 extra by Thursday.

"By Thursday" is just an example, any expression about a specific time would do. It could be derived from context too

John came to the restaurant last Thursday. I was working overtime, and I'd already earned $200 extra by then (or by that point).

Note that "thus far" has other meanings besides "up to this point" - the preceding explanation has to deal with your specific use case.

Answer 2

thus far is an idiom which means up to this point, so far. Yes, it is ok to use it with Past Perfect since the beginning of the sentence has also the Past Tense, the meaning is about the past.

Answer 3

These are some examples of thus far (in past time) found on Google Books.

In the simple past:

Rod Butler was right—it might have been a layman's logic, but it sounded right and made too much sense over a few beers out of earshot of the brass: werewolf DNA was the only DNA, thus far, that the scientists thought was capable of being fused with human DNA.
_{Bad Blood, L. A. Banks}

[...]; the new and newly trained I./JG 3 was positioned in the thus far untouched Munich region along with the JG 3 staff, newly transferred from the East; [...]
_{The Road to Big Week, Eric Hammel}

In the past perfect:

Lane, in fact, was being kind, because thus far in 1912 Joe Wood had been plain rank nearly as often as he had been in the front ranks.
_{Fenway 1912: The Birth of a Ballpark, a Championship Season, and Fenway's Remarkable First Year, Glenn Stout}

Robert Warren recalls that the establishment started to sit up and listen: 'It was clear that something major was going on. Thus far we'd had no success in reaching street culture with the Christian message.'
_{Rise and Fall of the Nine O'Clock Service, Roland Howard}

When the British army had advanced thus far on their road to Batavia, that city was observed to be on fire; and the general, naturally concluding that the enemy had either evacuated it, or meant to do so, sent forward the advance of the army under Colonel Gillespie, to take possession of it.
_{History of the French Revolution and of the Wars Produced by that Memorable Event, Christopher Kelly}

[...]; that the former was the saddest and the yellowest great statesman that I had had opportunity, thus far, to look upon, and the latter—well, it is not pleasant, even now, to recall how dead, how long time dead, she appeared.
_{Mark Twain's Library of Humor, Mark Twain}

(emphasis added)