Do Sync it's a list of tasks that you can create to execute in sequence one by one. When the last task was finished, the tesk go to callback in exec function.
consttesk=require('tesk').tesk;
constresult=newArray();
tesk()
.do((task)=>{
console.log('Do something 1');
// Simulating a asynchronous task like a database query
setTimeout(()=>{
result.push(1);
task.next();// Go to next task
},2000);
})
.do((task)=>{
console.log('Do something 2');
result.push(2);
task.next();// Go to next
})
.do((task)=>{
console.log('Do something 3');
result.push(3);
task.next();// Go to next task
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
console.log('Result expected: [1, 2, 3]');
console.log('Result:', result);
}
});
do(callback) - async usage
Do Async it's a list of tasks that you can create to execute without order. When all tasks was finished, the tesk go to callback in exec function. All tasks will be executed at same time (but not in parallel like a thread).
consttesk=require('tesk').tesk;
constresult=newArray();
tesk()
.do((task)=>{
console.log('Do something 1');
// Simulating a asynchronous task like a database query
setTimeout(()=>{
result.push(1);
task.next();// Go to next task
},2000);
})
.do((task)=>{
console.log('Do something 2');
result.push(2);
task.next();// Go to next task
})
.do((task)=>{
console.log('Do something 3');
result.push(3);
task.next();// Go to next task
})
.execAsync((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
console.log('Result expected: [2, 3, 1]');
console.log('Result:', result);
}
});
forEach(array, callback) - sync usage
ForEach sync is for iterate an array in sequence item by item and wait the current task finish to go to next item on array. When all tasks was finished, the tesk go to callback in exec function.
consttesk=require('tesk').tesk;
constresult=newArray();
tesk()
.forEach([1,2,3,4],(elem,index,task)=>{
if(index ==2){
setTimeout(()=>{
result.push(elem);
task.next();// Go to next task/item
},1);
}
else{
result.push(elem);
task.next();// Go to next task/item
}
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
console.log('Result expected: [1, 2, 3, 4]');
console.log('Result:', result);
}
});
forEach(array, callback) - async usage
ForEach async is for iterate an array without order. When all tasks was finished, the tesk go to callback in exec function. All tasks will be executed at same time (but not in parallel like a thread).
consttesk=require('tesk').tesk;
constresult='';
tesk()
.forEach([1,2,3,4],(elem,index,task)=>{
if(index ==2){
setTimeout(()=>{
result += elem;
task.next();// Go to next task/item
},1);
}
else{
result += elem;
task.next();
}
})
.execAsync((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
console.log('Result expected: [1, 2, 4, 3]');
console.log('Result:', result);
}
});
Accept a task
To accept a task just call the method next() from parameter task received on callback function. Error is null if all tasks was accepted.
tesk()
.do((task)=>{
task.next();// Go to next task
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
}
});
Reject a task
To reject a task just call the method reject() from parameter task received on callback function. When a task was rejected all tasks will be canceled and the callback function receive a personalized argument error.
tesk()
.do((task)=>{
task.reject('Error on execute query');// Reject task and send a personalized error
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
}
});
Another way
Exist another way to use. Tesk have a finally and catch function. If you use finally and catch, you don't use a callback argument on exec() function
tesk()
.do((task)=>{
console.log('Do something 1');
task.next();
})
.do((task)=>{
console.log('Do something 2');
task.next();
})
.finally(()=>{
console.log('All tasks finished!');
})
.catch((err)=>{
console.log('Errors', err);
})
.exec();
What not to do
Never use do() and forEach() together. It's doesn't work.
tesk()
.do((task)=>{
task.reject('Error on execute query');// Reject task and send a personalized error
})
.forEach([1,2,3,4],(elem,index,task)=>{
console.log(elem, index);
task.next();// Go to next task/item
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
}
});
If you need use do() and forEach() you can just call tesk() again.
tesk()
.do((task)=>{
task.reject('Error on execute query');// Reject task and send a personalized error
})
.exec((err)=>{
if(err){
console.log(err);
}
else{
console.log('Starting a forEach() tasks');
tesk()
.forEach([1,2,3,4],(elem,index,task)=>{
if(index ==2){
setTimeout(()=>{
result += elem;
task.next();// Go to next task/item
},1);
}
else{
result += elem;
task.next();
}
})
.execAsync((err)=>{
if(err){
console.log(err);
}
else{
console.log('All tasks finished!');
console.log('Result expected: [1, 2, 4, 3]');
console.log('Result:', result);
}
});
}
});
Tests
To run the test suite, first install the dependencies, then run npm run test:
$ npm install
$ npm run test
Coming soon
tesk.try() - Like a promise.race()
exec() or execAsync() - Receive in callback result array of all tasks. Then you will can use task.next(12), and when all tasks was finished you can receive error and result parameters. Result will be equals an array [12]
