Code editor

Works like VS Code, with a test runner. Fix a real bug without breaking anything, then add the test that would have caught it.

Your second week as a software engineer at Lakeshore Family Health. Amara Kim assigned you LFH-352, and the project is open below. (A made-up company. Start by running the tests.)

QuickCruit Code

/**
 * Money helpers for checkout. Everything after the catalog is whole cents,
 * so totals never pick up floating point dust.
 */
 
/** Turns a catalog price in dollars into whole cents. */
function toCents(dollars) {
  return Math.floor(dollars * 100);
}
 
/** Adds up a cart where each line is { price, qty }, with price in dollars. */
function cartTotalCents(lines) {
  return lines.reduce((sum, line) => sum + toCents(line.price) * line.qty, 0);
}
 
/** Takes a percentage off, to the nearest cent. */
function discount(cents, percent) {
  return Math.round((cents * (100 - percent)) / 100);
}
 
/** Shows cents as dollars, like $19.99. */
function formatCents(cents) {
  return "$" + (cents / 100).toFixed(2);
}
 
module.exports = { toCents, cartTotalCents, discount, formatCents };

/**
 * Money helpers for checkout. Everything after the catalog is whole cents,
 * so totals never pick up floating point dust.
 */

/** Turns a catalog price in dollars into whole cents. */
function toCents(dollars) {
  return Math.floor(dollars * 100);
}

/** Adds up a cart where each line is { price, qty }, with price in dollars. */
function cartTotalCents(lines) {
  return lines.reduce((sum, line) => sum + toCents(line.price) * line.qty, 0);
}

/** Takes a percentage off, to the nearest cent. */
function discount(cents, percent) {
  return Math.round((cents * (100 - percent)) / 100);
}

/** Shows cents as dollars, like $19.99. */
function formatCents(cents) {
  return "$" + (cents / 100).toFixed(2);
}

module.exports = { toCents, cartTotalCents, discount, formatCents };

No problems have been detected in the workspace.

Ln 1, Col 1

LFH-352Assigned to you

Checkout charges a cent less on some appointments

Amara KimSenior Engineer, Lakeshore Family Health

Finance found a pile of totals that are one cent short. A $17.58 line comes through as $17.57. It's small, but it happens thousands of times a day and the books have to balance.

There's a failing test in test/money.test.js that shows it. Can you fix it in src/money.js without breaking the other tests? Keep the change small, it goes out with today's release.

Then add one test for the edge case I'm most worried about: a cart with several of the same thing. 5 at $19.56 should come to exactly 9780 cents, because the missing cent gets multiplied by the quantity.

Lakeshore Family Health is a made-up company. A practice scenario, built for you.

Make the failing test pass
Keep every other test passing
Add one test for the edge case in the ticket

Saves your files, then runs every test, including the reviewer's.

/**

* Money helpers for checkout. Everything after the catalog is whole cents,

* so totals never pick up floating point dust.

/** Turns a catalog price in dollars into whole cents. */

function toCents(dollars) {

return Math.floor(dollars * 100);

}

/** Adds up a cart where each line is { price, qty }, with price in dollars. */

function cartTotalCents(lines) {

return lines.reduce((sum, line) => sum + toCents(line.price) * line.qty, 0);

}

/** Takes a percentage off, to the nearest cent. */

function discount(cents, percent) {

return Math.round((cents * (100 - percent)) / 100);

}

/** Shows cents as dollars, like $19.99. */

function formatCents(cents) {

return "$" + (cents / 100).toFixed(2);

}

module.exports = { toCents, cartTotalCents, discount, formatCents };