repl: keep reference count for `process.on('newListener')` · nodejs/node@999bf22

const kBufferedCommandSymbol = Symbol('bufferedCommand');

const kLoadingSymbol = Symbol('loading');

let addedNewListener = false;

function processNewListener(event, listener) {

if (event === 'uncaughtException' &&

process.domain &&

listener.name !== 'domainUncaughtExceptionClear' &&

domainSet.has(process.domain)) {

// Throw an error so that the event will not be added and the current

// domain takes over. That way the user is notified about the error

// and the current code evaluation is stopped, just as any other code

// that contains an error.

throw new ERR_INVALID_REPL_INPUT(

'Listeners for `uncaughtException` cannot be used in the REPL');

}

}

let processNewListenerUseCount = 0;

function addProcessNewListener() {

if (processNewListenerUseCount++ === 0) {

// Add this listener only once and use a WeakSet that contains the REPLs

// domains. Otherwise we'd have to add a single listener to each REPL

// instance and that could trigger the `MaxListenersExceededWarning`.

process.prependListener('newListener', processNewListener);

}

}

function removeProcessNewListener() {

if (--processNewListenerUseCount === 0) {

process.removeListener('newListener', processNewListener);

}

}

fixReplRequire(module);

// It is possible to introspect the running REPL accessing this variable

// from inside the REPL. This is useful for anyone working on the REPL.

module.exports.repl = this;

} else if (!addedNewListener) {

// Add this listener only once and use a WeakSet that contains the REPLs

// domains. Otherwise we'd have to add a single listener to each REPL

// instance and that could trigger the `MaxListenersExceededWarning`.

process.prependListener('newListener', (event, listener) => {

if (event === 'uncaughtException' &&

process.domain &&

listener.name !== 'domainUncaughtExceptionClear' &&

domainSet.has(process.domain)) {

// Throw an error so that the event will not be added and the current

// domain takes over. That way the user is notified about the error

// and the current code evaluation is stopped, just as any other code

// that contains an error.

throw new ERR_INVALID_REPL_INPUT(

'Listeners for `uncaughtException` cannot be used in the REPL');

}

});

addedNewListener = true;

} else {

addProcessNewListener();

this.once('exit', removeProcessNewListener);

}

domainSet.add(this._domain);