Stands for "Functional If..Else".
A helper function gives a functional "if" statement. Gives a unified output for both truthy/falsy branches. "const over let" fans, you are welcome! 😎
npm install fifelimport { fif } from 'fifel';
const result = fif(
Math.random() > 0.5,
() => 'truthy',
() => 'falsy'
);else branch is optional. If you don't need it, you can skip it:
import { fif } from 'fifel';
const result = fif(
Math.random() > 0.5,
() => {
// some logic
return 'truthy';
}
);This way, we use const instead of let for the result variable you expect to get.
It is more helpful when statements in if and else branches include multiple steps before the result is assigned or even some after that. With fif it is better structured:
import { fif } from 'fifel';
function getSomeFuits(amount = 5) {
const fruits = fif(
isEnoughInStock(amount),
() => {
const result = getFruitsFromStock(amount);
if (needToRefillStock()) {
const amountToRefill = getAmountToRefill();
stickANoteOnTheStock(`Please refill the stock (${amountToRefill} pcs)!`);
}
return {
fromStock: amount,
fromSupplier: 0,
full: true
};
},
() => {
const amountOnStock = getAmountOnStock();
const fromStock = getFruitsFromStock(amountOnStock);
stickANoteOnTheStock(`Stock is empty! Please refill!`);
const fromSupplier = getFruitsFromSupplier(amount - fromStock);
return {
fromStock,
fromSupplier,
full: fromStock + fromSupplier === amount
};
}
)
}Within the same logic, using if..else and let result would be less readable and assignment to result could be lost in lines of code.
fif function is typed. You can use it with TypeScript as well.
In previous examples, result types are inferred are perfectly inferred.
import { fif } from 'fifel';
// transport type is inferred as Car | Bike ✅
const transport = fif(
readyToGo(),
() => {
// some logic
return getCarFromGarage(); // returns Car
},
() => {
return buyBike(); // returns Bike
}
);import { fif } from 'fifel';
// transport type is inferred as Car | undefined ✅
const transport = fif(
readyToGo(),
() => {
// some logic
return getCarFromGarage(); // returns Car
}
);
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