Betters Stack Traces For Javascript FP

compose.js

const warningMessage = (fn) =>
    `Error running function '${fn.name}' with args:`

const composeReducer = (f, g) => (...args) => {
    var fResult, gResult;
    try {
        gResult = g(...args);
    } catch (e) {
        console.warn(warningMessage(g), args);
        throw e;
    }
    try {
        fResult = f(gResult);
    } catch (e) {
        console.warn(warningMessage(f), gResult);
        throw e;
    }
    return fResult;
};

const compose = (...fns) => fns.reduce(composeReducer);

// USAGE

// compose function
const __copy = compose(JSON.parse, JSON.stringify);

// define api
const copy = (data) => __copy(data);

const title = (str) => `<h1>${str}</h1>`;

// compose function
const __safeTitle = compose(title, copy);

// define api
const safeTitle = (str) => __safeTitle(str);

safeTitle();

// Error running function 'parse' with args: undefined
// Error running function 'copy' with args: [undefined]
// Uncaught SyntaxError: Unexpected token u in JSON at position 0
//    at parse (<anonymous>)
//    at args (<anonymous>:13:19)
//    at copy (<anonymous>:29:24)
//    at args (<anonymous>:7:19)
//    at safeTitle (<anonymous>:37:28)
//   at <anonymous>:1:1