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Runtime error
Runtime error
File size: 2,062 Bytes
a6b96c2 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | 'use strict';
/**
* Error that carries a process exit code. CLI logic throws this instead of
* calling process.exit() (banned by n/no-process-exit); runMain() translates it
* into process.exitCode at the entrypoint.
*
* @param {number} code exit code (default 1)
* @param {string} [message] optional human message; when set and code != 0 it is
* written to stderr by runMain before the process exits.
*/
class ExitError extends Error {
constructor(code = 1, message) {
super(message === undefined ? `process exit ${code}` : message);
this.name = 'ExitError';
this.code = code;
// Whether runMain should print this.message to stderr (only when a real
// message was provided, not the synthetic default).
this.hasUserMessage = message !== undefined;
}
}
/**
* Run a CLI main function and translate its outcome into process.exitCode
* (never process.exit(), so n/no-process-exit stays satisfied). Supports sync or
* async main.
* - main returns a number -> process.exitCode = that number
* - main throws/rejects ExitError -> process.exitCode = err.code, and if
* err.hasUserMessage && err.code !== 0, err.message is written to stderr
* - main throws/rejects anything else -> the stack is written to stderr and
* process.exitCode = 1
* Letting the event loop drain (vs process.exit) means buffered stdout/stderr is
* flushed and process.on('exit') cleanup handlers still fire.
*
* @param {() => (number|void|Promise<number|void>)} main
*/
function runMain(main) {
Promise.resolve()
.then(() => main())
.then((code) => {
if (typeof code === 'number') process.exitCode = code;
})
.catch((err) => {
if (err instanceof ExitError) {
if (err.hasUserMessage && err.code !== 0) {
process.stderr.write(`${err.message}\n`);
}
process.exitCode = err.code;
return;
}
process.stderr.write(`${err && err.stack ? err.stack : String(err)}\n`);
process.exitCode = 1;
});
}
module.exports = { ExitError, runMain };
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