formatISO

WARNING

formatISO is a date-fns helper, not a fedaco function. It appears in fedaco test fixtures because the e2e tests pin timestamps via formatISO(startOfSecond(now)).

What it does

Formats a Date into an ISO-8601 string. Used in tests to assert that fedaco serialises timestamps consistently.

import { formatISO, startOfSecond } from 'date-fns';

const now = new Date();
const reference = formatISO(startOfSecond(now)); // 2026-05-07T10:23:42+00:00

Why it shows up in fedaco docs

Several model assertions compare a serialised Date against formatISO(startOfSecond(now)) rather than now.toISOString(), because:

1. SQLite truncates fractional seconds depending on the column type.
2. startOfSecond(now) discards milliseconds before formatting, so the assertion holds regardless.

Real-World Use Cases (in your own code)

You typically don't need this — fedaco serialises model dates via the connection grammar's getDateFormat. If you're doing manual comparisons in tests:

import { formatISO, startOfSecond } from 'date-fns';

const post = await Post.createQuery().create({ published_at: now });

expect(post.published_at).toEqual(startOfSecond(now));
// or, comparing serialised forms:
expect(formatISO(post.published_at)).toBe(formatISO(startOfSecond(now)));

For producing serialised dates from a fedaco model, see the model's toArray output — date columns are formatted via serializeDate.

See Also

• date-fns formatISO docs
• startOfSecond — also from date-fns; discards fractional seconds.
• fromDateTime / setDateFormat — fedaco's own date handling.
• toArray — how fedaco serialises models for output.