$ emulates a sub shell, essentially it sets inheritStdio to false & captureStdio to true and then returns the result of stdioCombined().

Example Usage:

const branch = await $(_`git rev-parse --abbrev-ref HEAD`);

Also accepts a string template literal directly:

const branch = await $`git rev-parse --abbrev-ref HEAD`;

Or an list of arguments:

const branch = await $("git", "rev-parse", "--abbrev-ref", "HEAD");