tsc -w vs visual studio compile on save

[anjmao]

I'm using Typescript 1.8.10 and Karma in watch mode.

1. If I run tsc -w and change any file, karma detects that all my source files was changed (bad)
2. I have big solution with more what 1000 files and get a lot of annoyingINFO [watcher]: Changed file "...file.js" output messages in karma console (bad).
3. Usually I use fdescribe or fit jasmine methods to run only related tests for code changes. This makes tests run much faster, but I still should white up to 10 seconds because I get 1000 File changed messages in console. I tried to set karma logLevel to config.LOG_ERROR, but delay is still the same. (bad)
4. If use Visual Studio 2015 it works fine and karma notify only about one file changes which I'm editing (good)

Maybe we can emit only changed file, like in Visual Studio?

[mhegazy]

#6937 should fix this. a file is only modified if it has changed.