`tsc --watch` changes shell's current directory to ~ in Terminal.app while running

[verhovsky]

🔎 Search Terms

watch current directory

🕗 Version & Regression Information

• I was unable to test this on prior versions because it's too much work

⏯ Playground Link

No response

💻 Code

tsc --watch -p ./

🙁 Actual behavior

When running the above command in macOS's Terminal.app and pressing Cmd+t to open a new shell it opens a new shell at my home directory

🙂 Expected behavior

Terminal.app should open the new shell in the same directory that I ran the command from.

Additional information about the issue

webpack --watch

works the way I expect.

[RyanCavanaugh]

We never call chdir or equivalent as far as I can tell -- I don't know how Terminal.app decides what the new shell directory logic is, but maybe it's something else?

[verhovsky]

Yea, it's something to do with Terminal.app. iTerm2 does the right thing after enabling Profiles → Working Directory → Reuse previous session's directory and so does Alacritty.

[RyanCavanaugh]

If you can point to what we're doing wrong I'm happy to fix, but we don't have a realistic way to reverse engineer what Terminal.app is looking for / doing.

[typescript-bot]

This issue has been marked as "External" and has seen no recent activity. It has been automatically closed for house-keeping purposes.

[Dremora]

This has been bothering me for a while, so I decided to investigate.
The culprit is the code that clears the screen in watch mode. Thus, running tsc with --preserveWatchOutput serves as a workaround.
In sys.ts, in the clearScreen function, \x1Bc is sent to the stdout to erase the screen, where \x1B initiates an escape sequence and c executes Reset to Initial State, which, amongst other things, seems to reset current working directory in a macOS Terminal. You can easily test this theory by opening a node REPL and executing process.stdout.write("\x1Bc"), then opening a new terminal tab (or, depending on how your Terminal is configured, you may also see the working directory disappearing from the tab's title).

I've checked out how similar functionality is implemented in Jest, which doesn't suffer from the same issue. Jest is using a combination of 3 escape sequences (with a fallback to another combination on Windows):

• \u001B[2J - erases entire screen
• \u001B[3J - erases saved lines
• \u001B[H - moves cursor to home position (0, 0)

See also:

• https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
• Clear terminal in watch mode vitest-dev/vitest#3608

I'm happy to submit a PR if this issue gets reopened.