Clear terminal in watch mode

[gkiely]

Describe the bug

When using large amounts of text the terminal does not clear on save using macOS.

See #1183 for details.

Reproduction

See instructions from: #1183

System Info

System:
    OS: macOS 12.2.1
    CPU: (10) arm64 Apple M1 Pro
    Memory: 244.83 MB / 32.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 20.2.0 - ~/.volta/tools/image/node/20.2.0/bin/node
    Yarn: 1.22.18 - ~/.volta/tools/image/yarn/1.22.18/bin/yarn
    npm: 9.6.6 - ~/.volta/tools/image/node/20.2.0/bin/npm
    Watchman: 2023.04.10.00 - /opt/homebrew/bin/watchman
  Browsers:
    Brave Browser: 112.1.50.119
    Chrome: 114.0.5735.133
    Edge: 114.0.1823.51
    Firefox: 114.0
    Safari: 15.3

Used Package Manager

npm

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
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• The provided reproduction is a minimal reproducible example of the bug.

[AriPerkkio]

@gkiely this happens only on MacOS's built-in Terminal application, right? Any other terminal works fine at least based on my testing at #1183 (comment).

If I add following to the reproduction script, the terminal is cleared correctly:

// repro.mjs
const message = "Hello World";

await new Promise((r) => setTimeout(r, 1000));
Array(200).fill(0).forEach((_, i) => console.log(`Row ${i}`));
console.log("Scroll up now");

await new Promise((r) => setTimeout(r, 3000));
+ console.log('\x1B[2J\x1B[3J\x1B[H');
console.log(`\x1Bc${message}`); // Vitest's logger.clearFullScreen
console.log("Testing");

This is something that could probably be added here:

vitest/packages/vitest/src/node/logger.ts

Line 46 in f427f00

this.console.log(`\x1Bc${message}`)

+   this.console.log('\x1B[2J\x1B[3J\x1B[H')
    this.console.log(`\x1Bc${message}`)

This seems to work at least on my machine but I'm not really familiar with raw ANSI-codes. I picked the sequence from here: sindresorhus/ansi-escapes#25 (comment).

[gkiely]

this happens only on MacOS's built-in Terminal application, right?

Yes

[AriPerkkio]

Jest clears the scrollbar and terminal where vitest does not.
#1183 (comment)

Jest seems to indeed be using different ANSI codes than Vitest. We should try to change Vitest to use the same \x1B[2J\x1B[3J\x1B[H and do extensive testing with different terminals on different OS's:

• https://github.com/jestjs/jest/blob/f4172f5bc0ca1eaffad417135222d2102aeab7f2/packages/jest-util/src/specialChars.ts#L18
• https://github.com/jestjs/jest/blob/f4172f5bc0ca1eaffad417135222d2102aeab7f2/packages/jest-core/src/watch.ts#L283