Tomer Aberbach

@tomeraberba.ch

Working on Stainless · Previously Google Docs · TCNJ grad · Enthused by computer science and music composition/production https://tomeraberba.ch

const letterArb = fc.record({ id: fc.string() });

test("helping Santa", () => {
fc.assert(
fc.property(fc.array(letterArb), (letters) => {
const deduplicatedLetters = dropLettersFromDuplicatedSenders(letters);

const lettersById = Map.groupBy(letters, ({ id }) => id);
const expectedLetters = Array.from(
lettersById.values(),
(letters) => letters[0]
);
// Manually check length and individual items for reference equality.
expect(deduplicatedLetters.length).toBe(expectedLetters.length);
for (let i = 0; i < deduplicatedLetters.length; i++) {
expect(deduplicatedLetters[i]).toBe(expectedLetters[i]);
}
})
);
});

$const nameArb = fc.stringMatching(/^[a-z]+$/); const ageArb = fc.integer({ min: 7, max: 77 }); test("helping Santa", () => { fc.assert( fc.property( fc .tuple(ageArb, fc.array(nameArb)) .map(([age, names]) => [age, names.map((name) => ({ name, age }))]), ([age, letters]) => { const sortedLetters = sortLetters(letters); expect(sortedLetters.length).toBe(letters.length); for (const letter of letters) { expect(letter.age).toBe(age); } for (let i = 1; i < sortedLetters.length; i++) { const previousLetter = sortedLetters[i - 1]; const currentLetter = sortedLetters[i]; // Failed here! expect(previousLetter.name <= currentLetter.name).toBe(true); } } ) ); });$