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Termwright

Type Alias: EnvMode

@termwright/driver

@termwright/driver / EnvMode

Type Alias: EnvMode

Section titled “Type Alias: EnvMode”

EnvMode = "inherit" | "replace"

Defined in: driver/src/api.ts:85

How the child’s environment is built.

  • 'replace' (default, secret-safe): only a documented allowlist of variables the child genuinely needs (PATH, HOME, LANG, LC_ALL, SHELL, TMPDIR, USER on POSIX; the longer Windows list adds SystemRoot, PATHEXT and the profile variables) plus everything in LaunchOptions.env;
  • 'inherit': the parent’s full environment, plus LaunchOptions.env.

The termwright handshake variables are injected in both modes.

TERM and COLORTERM are set by the driver in both modes, to xterm-256color and truecolor, and are not inherited: the child’s terminal is this driver’s emulator, whose capabilities are known exactly, so passing on whatever terminal launched the test run would describe something the child is not attached to — and passing on nothing (a Windows runner has no TERM of its own) leaves ncurses-style libraries guessing. An explicit entry in LaunchOptions.env still wins, for a caller testing how their program behaves under a different TERM.