tsc incremental compilation rewrites all files on docker (for windows) volume

[wclr]

TypeScript Version: nightly (2.2.0-dev.201xxxxx)

tsc incremental compilation rewrites all compiled files on docker volume (docker for windows)

To reproduce it:

• install docker for windows or try with your instlaled docker
• create dir and make npm init
• npm install typescript@next
• create two files 1.ts and 2.ts with some code.
• run tsc in docker docker run --rm -v FULL_PATH_TO_YOUR_DIR:/app -w /app mhart/alpine-node:7.1.0 ./node_modules/.bin/tsc -w
• see that tsc created both files 1.js and 2.js
• wait some minute then change the code of only 1.ts
• tsc will recompile
• see the date for 1.js and 2.js, you will see that 2.js too has been rewritten, though it should not be the case (it is not the case if you run tsc without docker windows)

This happens due to this check:
https://github.com/Microsoft/TypeScript/blob/e4b81d03311ae157486dd2ebbd7d381996066174/src/compiler/program.ts#L148

and that ts.getModifiedTime returns strange result, probably this is not a typescript issue, but docker/node, but an issue for typescript users.

Btw what is a reason to check time modified, isn't the hash is just enough?

Windows 10, docker for windows 1.12.5 (this the same case should be for docker for mac)

[jngbng]

It also happens on Docker for mac and makes the docker keep consuming lots of cpu resources.

[jngbng]

I found the reason why the cpu is pegged at 100% from here:
https://forums.docker.com/t/docker-compose-volumes-gulp-watch-100-cpu-usage/10192/7

TSC uses fs.watchFile as well and suffers the same problem: https://github.com/Microsoft/TypeScript/blob/e4b81d03311ae157486dd2ebbd7d381996066174/src/compiler/sys.ts#L464

[mhegazy]

@sheetalkamat is there anything we can do here?

[sheetalkamat]

@mhegazy this seems like same as #19762 and i am in final stages of prototyping few different behaviors for watching files/directories to get feedback and we can make decision afterwards