tsc-watch 消耗 TSC_NONPOLLING_WATCHER 吗？

Question

I am working on microservice integration project. I run 8 typescript services at the same time using tsc-watch --preserveWatchOutput --onSuccess 'node build/index.js' .

The processes consume 70% of my CPU, even when I make no source code at all. I figured there is some polling for changes going on and googled that setting environment variable TSC_NONPOLLING_WATCHER to "1" will stop the polling.

This is the source of the hint: https://medium.com/@julioromano/writing-typescript-on-a-laptop-this-might-improve-your-battery-life-f503dd16f019

It does however seem to have no effect at all. Also, the author mentions "tsc -w" and not tsc-watch. I do not quite understand what the difference is between tsc -w and tsc-watch.

I would be thankful for any help.

Answer 1

Update 1 no changed in tsconfig.json needed

I run into a similar problem and are going to solve it by setting the environment variable TSC_NONPOLLING_WATCHER="1" properly.

In my case i had to adjust .zprofile via

export TSC_NONPOLLING_WATCHER="1"

You can test it in a command shell via echo $TSC_NONPOLLING_WATCHER .

Alternative

If this doesn't help try to set the tsconfig.json files to the following:

"watchOptions": {
    // Use native file system events for files and directories
    "watchFile": "useFsEvents",
    "watchDirectory": "useFsEvents",

    // Poll files for updates more frequently
    // when they're updated a lot.
    "fallbackPolling": "dynamicPriority"
}

These options come from: https://www.typescriptlang.org/docs/handbook/configuring-watch.html and I highly suggest reading through it before doing any changes.

tsc vs tsc-watch

About the difference between tsc -w and tsc-watch the project on github claimes and I quote:

• tsc-watch is using the currently installed TypeScript compiler.
• tsc-watch is not changing the compiler, just adds the new arguments, compilation is the same, and all other arguments are the same.

So all settings for tsc should work as well in tsc-watch like in your case.