This is what I have so far:
function isFunction(functionToCheck) {
return functionToCheck && {}.toString.call(functionToCheck) === '[object Function]';
}
////////////////// Implementing pipe function ////////////////////
const pipe = (value, ...funcs) => {
try {
const result = funcs.reduce(function (acc, currFunc) {
if (isFunction(currFunc) === false)
throw new ('Provided argument at position 2 is not a function!');
return currFunc(acc);
}, value);
return result;
} catch (err) {
return err.message;
}
};
///////////////////////////////////////////////////////////////
const replaceUnderscoreWithSpace = (value) => value.replace(/_/g, ' ');
const capitalize = (value) =>
value
.split(' ')
.map((val) => val.charAt(0).toUpperCase() + val.slice(1))
.join(' ');
const appendGreeting = (value) => `Hello, ${value}!`;
const error = pipe('john_doe', replaceUnderscoreWithSpace, capitalize, '');
alert(error); // Provided argument at position 2 is not a function!
const result = pipe('john_doe', replaceUnderscoreWithSpace, capitalize, appendGreeting);
alert(result); // Hello, John Doe!
I couldn’t find the solution. Probably somebody could help me. Thanks in advance.
You can use Array#reduce to use each function and pass the value as the accumulator, you can also use instanceofFunction to make sure that each argument is a function.
const isFunction = (func) => func instanceof Function;
const pipe = (value, ...funcs) => {
return funcs.reduce((acc, func, idx) => {
if (!isFunction(func)) {
throw new Error(
`Provided argument at position ${idx} is not a function!`
);
}
return func(acc);
}, value);
};
const split = (x) => x.split("");
const reverse = (x) => x.reverse();
const join = (x) => x.join("");
const test = pipe("a man a plan a canal, panama", split, reverse, join);
console.log(test);