The last Test in Pakistan was scheduled to be played from March 1 to 5, 2009.
There was no play after the second day. A contemporary report:
https://www.espncricinfo.com/story/_/id/22788732/sl-cricketers-injured-terror-attack
And the scorecard, for what it is worth:
Since then, Pakistan has played Tests only away or at neutral venues (mainly in UAE, also 2 in England). There have been a small number of T20Is and ODIs played in Pakistan in the past few years:
T20Is in Pakistan since March 2009:
ODIs in Pakistan since March 2009:
It is also apparent that any Pakistani player who made his Test debut since 3 March 2009 would never have played at home until now. They are:
It can be seen that these 46 players include the present captain (Azhar Ali) and the previous captain (Sarfaraz Ahmed) who made their debuts in 2010, besides key players such as Asad Shafiq and Shan Masood. There is also Fawad Alam who made his debut in Sri Lanka in 2009 but has not played any Test since that series, but may well play in the forthcoming series.
And there are others such as Saeed Ajmal and Mohammad Amir who came and went without ever playing in a home Test.
You can see a review of past Tests between Pakistan and Sri Lanka here:
https://abn397.wordpress.com/2017/10/13/review-of-pakistan-sri-lanka-tests/
Note that their last meeting was in the UAE in late 2017, when Sri Lanka won 2-0. They were among the very few teams to beat Pakistan in a series in the UAE.