Hands the terminal to an editor, and takes back whatever was saved.

A path as a person would say it: qunitx-cli/lib/repl/session.ts for something in this project, and the absolute path for anything outside it.

Opens a file at a line in the developer's editor, or says why it could not.

.open, .edit and .e — whichever editor the environment prefers.

What .open and every editor-named spelling of it do, differing only in which editor they mean.

Stops the prompt reading, because what happens next is not the prompt's.

A file's contents, or null when it cannot be read — a missing path is an answer, not a crash.

The lines of a session worth replaying: everything typed, minus the shell escapes.

Gives the prompt back its input — unless the session has gone.

How an answer to [Y/n] is read: Enter, or anything starting with y. Everything else is no.

What an edit leaves to run: the buffer where it moved, and nothing where it did not.

True when the file was written. A save that cannot land is a message, not a crashed session.