Unhandle Promise rejection inside try block

-2

I'm having difficulties understanding why the code below throws an Unhandled Promise Rejection Warning :

router.post('/stampaClasse/:as(20[0-9][0-9]/[0-9][0-9])/:classe([1-8])',async function (req,res,next)

 const sezioni = await Classi.getSezioniFromAnnoScolasticoAndClasse(req.params.as,req.params.classe);
 let options = 
 semestre: req.body.semestre,
 fontSize: req.body.fontSize,
 textColor: '#515151',
 gridColor: '#bec0be',
 corDidattico:
 titolo:'prof.',
 nome:'Roberto',
 cognome:'Dalema'
 
 
 let newPDF = new pdfKit();
 try
 for(sezione of sezioni)

 const idStudentiPromise = Classi.getStudentiFromAnnoScolasticoAndClasseAndSezione(req.params.as,req.params.classe,sezione)
 const materiePromise = Classi.getMaterieSezione(req.params.as,req.params.classe,sezione)
 const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )


 let classe = 
 annoScolastico: req.params.as,
 classe : req.params.classe,
 sezione: sezione,
 materie: await materiePromise,
 studenti: await infoStudentiPromise
 
 for(studente of classe.studenti)
 studente.pagelleMateriePromises = classe.materie.map(async m=>Pagelle.getPagellaFromStudente(classe.annoScolastico,classe.classe,classe.sezione,m,studente.id));
 
 for(studente of classe.studenti)
 studente.pagelleMaterie = await Promise.all(studente.pagelleMateriePromises)
 addHeader(newPDF,studente,classe,options);
 addPagelleSemestre(newPDF,studente,classe,options);
 addFooter(newPDF,studente,classe,options);
 
 

 newPDF.pipe(res);
 newPDF.end();
 
 catch(err)
 next(err)
 
);

The error occurs multiple times, and it is caused by the fact that at line

const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )

idStudentiResults alredy returns a Promise.all()

regardles of what is causing the error i'd like to know why it says the error is not beeing handled. Is the try catch not enaugh?

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

Promise.all takes an array of promises and resolves them in a then block. Check out this, it might be helpful: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

– squeekyDave
Nov 12 '18 at 17:17

Hi! Please take the tour, have a look around, and read through the help center, in particular How do I ask a good question? I'd also check out Jon Skeet's question checklist and Writing the Perfect Question. Please update your question with a Minimal, Complete, and Verifiable example demonstrating the problem, ideally a runnable one using Stack Snippets (the [<>] toolbar button; here's how to do one).

– T.J. Crowder
Nov 12 '18 at 17:18

1

You've said Module.getInfo(ids) returns a promise, not an array. If that's true (showing us would be much better), then why are you passing it into Promise.all? That would seem to serve no purpose...

– T.J. Crowder
Nov 12 '18 at 17:19

1

why it is saying the error is unhandled because the error is unhanded. A normal try / catch is not able to catch a promise error, unless you used async / awat, and did await Promise.all()

– Keith
Nov 12 '18 at 17:23

Why are you wrapping a promise with a promise

– Kevin B
Nov 12 '18 at 17:28

|
show 3 more comments

-2

I'm having difficulties understanding why the code below throws an Unhandled Promise Rejection Warning :

router.post('/stampaClasse/:as(20[0-9][0-9]/[0-9][0-9])/:classe([1-8])',async function (req,res,next)

 const sezioni = await Classi.getSezioniFromAnnoScolasticoAndClasse(req.params.as,req.params.classe);
 let options = 
 semestre: req.body.semestre,
 fontSize: req.body.fontSize,
 textColor: '#515151',
 gridColor: '#bec0be',
 corDidattico:
 titolo:'prof.',
 nome:'Roberto',
 cognome:'Dalema'
 
 
 let newPDF = new pdfKit();
 try
 for(sezione of sezioni)

 const idStudentiPromise = Classi.getStudentiFromAnnoScolasticoAndClasseAndSezione(req.params.as,req.params.classe,sezione)
 const materiePromise = Classi.getMaterieSezione(req.params.as,req.params.classe,sezione)
 const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )


 let classe = 
 annoScolastico: req.params.as,
 classe : req.params.classe,
 sezione: sezione,
 materie: await materiePromise,
 studenti: await infoStudentiPromise
 
 for(studente of classe.studenti)
 studente.pagelleMateriePromises = classe.materie.map(async m=>Pagelle.getPagellaFromStudente(classe.annoScolastico,classe.classe,classe.sezione,m,studente.id));
 
 for(studente of classe.studenti)
 studente.pagelleMaterie = await Promise.all(studente.pagelleMateriePromises)
 addHeader(newPDF,studente,classe,options);
 addPagelleSemestre(newPDF,studente,classe,options);
 addFooter(newPDF,studente,classe,options);
 
 

 newPDF.pipe(res);
 newPDF.end();
 
 catch(err)
 next(err)
 
);

The error occurs multiple times, and it is caused by the fact that at line

const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )

idStudentiResults alredy returns a Promise.all()

regardles of what is causing the error i'd like to know why it says the error is not beeing handled. Is the try catch not enaugh?

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

Promise.all takes an array of promises and resolves them in a then block. Check out this, it might be helpful: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

– squeekyDave
Nov 12 '18 at 17:17

Hi! Please take the tour, have a look around, and read through the help center, in particular How do I ask a good question? I'd also check out Jon Skeet's question checklist and Writing the Perfect Question. Please update your question with a Minimal, Complete, and Verifiable example demonstrating the problem, ideally a runnable one using Stack Snippets (the [<>] toolbar button; here's how to do one).

– T.J. Crowder
Nov 12 '18 at 17:18

1

You've said Module.getInfo(ids) returns a promise, not an array. If that's true (showing us would be much better), then why are you passing it into Promise.all? That would seem to serve no purpose...

– T.J. Crowder
Nov 12 '18 at 17:19

1

why it is saying the error is unhandled because the error is unhanded. A normal try / catch is not able to catch a promise error, unless you used async / awat, and did await Promise.all()

– Keith
Nov 12 '18 at 17:23

Why are you wrapping a promise with a promise

– Kevin B
Nov 12 '18 at 17:28

|
show 3 more comments

-2

I'm having difficulties understanding why the code below throws an Unhandled Promise Rejection Warning :

router.post('/stampaClasse/:as(20[0-9][0-9]/[0-9][0-9])/:classe([1-8])',async function (req,res,next)

 const sezioni = await Classi.getSezioniFromAnnoScolasticoAndClasse(req.params.as,req.params.classe);
 let options = 
 semestre: req.body.semestre,
 fontSize: req.body.fontSize,
 textColor: '#515151',
 gridColor: '#bec0be',
 corDidattico:
 titolo:'prof.',
 nome:'Roberto',
 cognome:'Dalema'
 
 
 let newPDF = new pdfKit();
 try
 for(sezione of sezioni)

 const idStudentiPromise = Classi.getStudentiFromAnnoScolasticoAndClasseAndSezione(req.params.as,req.params.classe,sezione)
 const materiePromise = Classi.getMaterieSezione(req.params.as,req.params.classe,sezione)
 const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )


 let classe = 
 annoScolastico: req.params.as,
 classe : req.params.classe,
 sezione: sezione,
 materie: await materiePromise,
 studenti: await infoStudentiPromise
 
 for(studente of classe.studenti)
 studente.pagelleMateriePromises = classe.materie.map(async m=>Pagelle.getPagellaFromStudente(classe.annoScolastico,classe.classe,classe.sezione,m,studente.id));
 
 for(studente of classe.studenti)
 studente.pagelleMaterie = await Promise.all(studente.pagelleMateriePromises)
 addHeader(newPDF,studente,classe,options);
 addPagelleSemestre(newPDF,studente,classe,options);
 addFooter(newPDF,studente,classe,options);
 
 

 newPDF.pipe(res);
 newPDF.end();
 
 catch(err)
 next(err)
 
);

The error occurs multiple times, and it is caused by the fact that at line

const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )

idStudentiResults alredy returns a Promise.all()

regardles of what is causing the error i'd like to know why it says the error is not beeing handled. Is the try catch not enaugh?

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

I'm having difficulties understanding why the code below throws an Unhandled Promise Rejection Warning :

router.post('/stampaClasse/:as(20[0-9][0-9]/[0-9][0-9])/:classe([1-8])',async function (req,res,next)

 const sezioni = await Classi.getSezioniFromAnnoScolasticoAndClasse(req.params.as,req.params.classe);
 let options = 
 semestre: req.body.semestre,
 fontSize: req.body.fontSize,
 textColor: '#515151',
 gridColor: '#bec0be',
 corDidattico:
 titolo:'prof.',
 nome:'Roberto',
 cognome:'Dalema'
 
 
 let newPDF = new pdfKit();
 try
 for(sezione of sezioni)

 const idStudentiPromise = Classi.getStudentiFromAnnoScolasticoAndClasseAndSezione(req.params.as,req.params.classe,sezione)
 const materiePromise = Classi.getMaterieSezione(req.params.as,req.params.classe,sezione)
 const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )


 let classe = 
 annoScolastico: req.params.as,
 classe : req.params.classe,
 sezione: sezione,
 materie: await materiePromise,
 studenti: await infoStudentiPromise
 
 for(studente of classe.studenti)
 studente.pagelleMateriePromises = classe.materie.map(async m=>Pagelle.getPagellaFromStudente(classe.annoScolastico,classe.classe,classe.sezione,m,studente.id));
 
 for(studente of classe.studenti)
 studente.pagelleMaterie = await Promise.all(studente.pagelleMateriePromises)
 addHeader(newPDF,studente,classe,options);
 addPagelleSemestre(newPDF,studente,classe,options);
 addFooter(newPDF,studente,classe,options);
 
 

 newPDF.pipe(res);
 newPDF.end();
 
 catch(err)
 next(err)
 
);

The error occurs multiple times, and it is caused by the fact that at line

const infoStudentiPromise = Promise.all( Studenti.getInfoStudentiById(await idStudentiResults) )

idStudentiResults alredy returns a Promise.all()

regardles of what is causing the error i'd like to know why it says the error is not beeing handled. Is the try catch not enaugh?

javascript node.js express promise

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

edited Nov 13 '18 at 9:30

asked Nov 12 '18 at 17:14

Filippo Bosco

134

asked Nov 12 '18 at 17:14

Filippo Bosco

134

asked Nov 12 '18 at 17:14

Filippo Bosco

134

Promise.all takes an array of promises and resolves them in a then block. Check out this, it might be helpful: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

– squeekyDave
Nov 12 '18 at 17:17

Hi! Please take the tour, have a look around, and read through the help center, in particular How do I ask a good question? I'd also check out Jon Skeet's question checklist and Writing the Perfect Question. Please update your question with a Minimal, Complete, and Verifiable example demonstrating the problem, ideally a runnable one using Stack Snippets (the [<>] toolbar button; here's how to do one).

– T.J. Crowder
Nov 12 '18 at 17:18

1

You've said Module.getInfo(ids) returns a promise, not an array. If that's true (showing us would be much better), then why are you passing it into Promise.all? That would seem to serve no purpose...

– T.J. Crowder
Nov 12 '18 at 17:19

1

why it is saying the error is unhandled because the error is unhanded. A normal try / catch is not able to catch a promise error, unless you used async / awat, and did await Promise.all()

– Keith
Nov 12 '18 at 17:23

Why are you wrapping a promise with a promise

– Kevin B
Nov 12 '18 at 17:28

|
show 3 more comments

Promise.all takes an array of promises and resolves them in a then block. Check out this, it might be helpful: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

– squeekyDave
Nov 12 '18 at 17:17

Hi! Please take the tour, have a look around, and read through the help center, in particular How do I ask a good question? I'd also check out Jon Skeet's question checklist and Writing the Perfect Question. Please update your question with a Minimal, Complete, and Verifiable example demonstrating the problem, ideally a runnable one using Stack Snippets (the [<>] toolbar button; here's how to do one).

– T.J. Crowder
Nov 12 '18 at 17:18

1

You've said Module.getInfo(ids) returns a promise, not an array. If that's true (showing us would be much better), then why are you passing it into Promise.all? That would seem to serve no purpose...

– T.J. Crowder
Nov 12 '18 at 17:19

1

why it is saying the error is unhandled because the error is unhanded. A normal try / catch is not able to catch a promise error, unless you used async / awat, and did await Promise.all()

– Keith
Nov 12 '18 at 17:23

Why are you wrapping a promise with a promise

– Kevin B
Nov 12 '18 at 17:28

Promise.all takes an array of promises and resolves them in a then block. Check out this, it might be helpful: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

– squeekyDave
Nov 12 '18 at 17:17

Hi! Please take the tour, have a look around, and read through the help center, in particular How do I ask a good question? I'd also check out Jon Skeet's question checklist and Writing the Perfect Question. Please update your question with a Minimal, Complete, and Verifiable example demonstrating the problem, ideally a runnable one using Stack Snippets (the [<>] toolbar button; here's how to do one).

– T.J. Crowder
Nov 12 '18 at 17:18

You've said Module.getInfo(ids) returns a promise, not an array. If that's true (showing us would be much better), then why are you passing it into Promise.all? That would seem to serve no purpose...

– T.J. Crowder
Nov 12 '18 at 17:19

why it is saying the error is unhandled because the error is unhanded. A normal try / catch is not able to catch a promise error, unless you used async / awat, and did await Promise.all()

– Keith
Nov 12 '18 at 17:23

Why are you wrapping a promise with a promise

– Kevin B
Nov 12 '18 at 17:28

|
show 3 more comments

1 Answer
1

active

oldest

votes

Promise.all needs to receive an array of promises as param. Make sure that Module.getInfo(ids) is returning that.

answered Nov 12 '18 at 17:16

rubentd

1,089821

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

1

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

add a comment |

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1 Answer
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active

oldest

votes

1 Answer
1

active

oldest

votes

Promise.all needs to receive an array of promises as param. Make sure that Module.getInfo(ids) is returning that.

answered Nov 12 '18 at 17:16

rubentd

1,089821

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

1

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

add a comment |

Promise.all needs to receive an array of promises as param. Make sure that Module.getInfo(ids) is returning that.

answered Nov 12 '18 at 17:16

rubentd

1,089821

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

1

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

add a comment |

Promise.all needs to receive an array of promises as param. Make sure that Module.getInfo(ids) is returning that.

answered Nov 12 '18 at 17:16

rubentd

1,089821

Promise.all needs to receive an array of promises as param. Make sure that Module.getInfo(ids) is returning that.

answered Nov 12 '18 at 17:16

rubentd

1,089821

answered Nov 12 '18 at 17:16

rubentd

1,089821

answered Nov 12 '18 at 17:16

rubentd

1,089821

answered Nov 12 '18 at 17:16

rubentd

1,089821

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

1

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

add a comment |

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

1

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

Maybe share the code for Module.getInfo and tell us what exactly is that you're trying to achieve

– rubentd
Nov 12 '18 at 17:17

I know where the error lies, what i don't know is why it is saying the error is unhandled

– Filippo Bosco
Nov 12 '18 at 17:19

This line doesn't have a catch for the promises: const infoPromise = Promise.all( Module.getInfo(ids) );

– rubentd
Nov 12 '18 at 17:32

Do you mean i need a try-catch block for every line of code if that code execute some asyncronous operation?

– Filippo Bosco
Nov 12 '18 at 17:42

@FilippoBosco Not a try-catch block but the .catch method for Promises

– rubentd
Nov 12 '18 at 18:01

add a comment |

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