Hi, my name is Cabzki, and I would like to share with you my observations regarding the new villagers for Minecraft 1.14.
I made this because I was trying to make a Villager Trading hall in my world, but failed to do so. That prompted me to study the villager behaviors. I would like to stress that all information I have put down below are my own observations, so some information here may not be 100% correct. Also, this one focuses on the villager behavior regarding their jobs (So nothing about breeding and/or iron farms). Here we go!
Points below were tested on Minecraft 1.14.1.
• You can check for a villager's job site and bed with the command /data get entity <x> Brain. Look at a specific villager and type the command. The value of <x> should appear in the autocomplete if you look at it. Normally the value is a string of numbers and letters.
• Villagers can "see" a job site if they can find a path to it. They will try to go to a block beside the job site or stand on the job site block itself. The job site can be 1 block above from where they are standing. 2 blocks above won't work since they can't get to a block beside the job site (Unless there is a path). They can access a job site regardless of the block above it. (It can be an air/solid/transparent block). See this image for an example.
• If a villager's chosen job site is 1 block above, they will be able to see it, but not use it. That means they won't be able to stock their supplies.
• You can lock a villager's profession(trades) by trading with them at least once to give them experience. You can remove their job site, but they won't go back to being jobless. They won't be able to restock their trades if you take it away though. Example here. They will also not accept any other job sites that does not correspond to their profession. Example.
• Villagers cannot see a job site if they are standing in a 1x1 hole. They must have room to walk in order to see a job site. Minimum is a 1x2 area. Here's an example. The job sites on the leftmost/rightmost cells are similar to the ones in the middle, but they could not get their jobs. If you try to put them in a 1x2 cell, give them a profession, then push them with a piston, they will lose their profession. You can still trade with them if you lock their trades, then put them in a 1x1 hole, but they won't be able to restock.
• A villager can detect job sites as far as 48 blocks. Example. Each red wool is 5 blocks.
• A villager can claim a job site when in a minecart or boat. See example above. Villager is in a boat.
• If a villager claims a job site while in a minecart or boat, other villagers will not be able to claim the specific job site chosen. However, if you drop off a villager (with a profession) into an area where they won't be able to path find to their chosen job site. They will try to run towards the direction of the job site (against the wall) for a few seconds, then revert back to being jobless if you haven't traded with them. If their trades are locked, they just won't be able to restock once their supplies run out.
That's all that I have observed. I hope anyone who passes through this thread will find this useful. Thank you very much! Feel free to share/discuss/ask questions.
As stated, villagers in boats have no problem claiming a jobsite but I have yet to have one restock his trades and they take forever to lose their profession, like several days at least, if their jobsite block is destroyed or the path blocked.
I wish you could easily trace the bed/work station each one belongs to. I have a few that seem to have adopted items far away in buildings I built. I'd like to move them in and get them to stay in that area. But many seem to be torn between beds and workstations that are too far away.