Throwing custom error in knex transaction cause api to crash - node.js

Question

I am currently working on api with knex. I have to perform some operations in one big transaction and have to valdiate there also - if any validation returns "false" - transaction must be stoped. Problem is, whenever I toss "my" error there, even though all "Catch"es gets it and res is sended corrently- right after that my whole api crash with error:
Cannot read property "removeListener" of null
which is strange, becouse there are no similar issues with catching errors caused by knex itself.
Strangley, if i would remove throwing of my errors - i will still get unhandled exception
Cannot read property "rollback" of null
in code it looks like this:
f1(){
// (...)
let noErrors = true;
return global.knex
.transaction((trx) => {
return operation1(trx) //Knex operation returning object with parameter "correct"
.then((output)=>{
if(output.correct === false)
throw new Error('CustomError');
})
.then(()=>{ return operation2(trx); })
.then(()=>{ return operation3(trx); })
// (...)
.then(trx.commit)
.catch((error) => {
console.error('TRANS. FAILED');
noErrors = false;
trx.rollback();
throw error; // Both with and without it - failed
});
})
.then(() => {
console.log('TRANS. OK');
})
.then(() => {
if(noErrors)
return {result:'MyResultsHere'};
else
return {result:'ErrorOccured'};
})
.catch((error) => {
return {result:'ErrorOccuredAgain'};
});
}
This function's result (promise) is then returned :
f1().then((output)=>{
console.log(output.result);
// (...) sending response for request here
}
.catch((err) => {
console.error(err);
res.status(500).send();
});
AFter some additiona ltesting - it appears liek i can throw my custom errors, but issue here is with rollback - and soemtiems i get one more error:
TransactionError: Requests can only be made in the LoggedIn state, not
the SentClientRequest state

Answer 1

Looks like you are mixing 2 different transaction handling syntaxes (simple examples below):
knex.transaction(trx => {
// returning promise automatically calls commit / rollback
return operation(1);
})
.then(results => console.log("commit was called automatically", results))
.catch(err => console.log("rollback was called automatically", err))
and
knex.transaction(trx => {
// NOT returning promise so you need to call commit / rollback explicitly
operation(1).then(results => trx.commit(results))
.catch(err => trx.rollback(err));
})
.then(results => console.log("stuff from transaction commit", results))
.catch(err => console.log("error passed to rollback", err))
You are probably trying to do this:
f1(){
// (...)
return global.knex
.transaction(trx => {
return operation1(trx)
.then(output => {
if(output.correct === false) {
// if wrong results promise will reject with "CustomError"
throw new Error('CustomError');
}
})
.then(() => operation2(trx))
.then(() => operation3(trx))
// (...)
;
})
.then(resultsOfLastThen => {
console.log('TRANS. OK', resultsOfLastOperation);
return { result: 'MyResultsHere' };
})
.catch(error => {
return { result: 'ErrorOccured' };
});
}