inOrder

Assert that spies fired in a relative order.

Signatures

function inOrder(...entries: (MethodSpy | InvocationHandle)[]): void

inOrder.at(spy: MethodSpy, index: number): InvocationHandle
inOrder.strict(...entries: (MethodSpy | InvocationHandle)[]): void

inOrder(...) — first-of-each ordering

Compares the first recorded call of each spy by its monotonic sequence number, asserting they match the argument order.

inOrder(db.spy.connect, db.spy.query, log.spy.info)

Throws:

• inOrder: at least one spy is required — zero args
• inOrder: each argument must be a MethodSpy ... — non-spy arg
• inOrder: \db.query` was never called` — listed spy has no calls
• inOrder: \log.info` (seq N) fired before `db.query` (seq M)` — wrong order

inOrder.at(spy, index)

Wraps a spy into a handle that points at the N-th (0-indexed) recorded call, rather than the first.

inOrder(
  inOrder.at(db.spy.query, 0),    // first query
  inOrder.at(db.spy.query, 1),    // then second query
)

Out-of-range indices throw:

inOrder(inOrder.at(db.spy.query, 99))
// throws: `db.query` invocation 99 was never called

Mix and match with plain spies:

inOrder(
  db.spy.connect,
  inOrder.at(db.spy.query, 2),
  log.spy.info,
)

inOrder.strict(...)

Like inOrder, but fails if any listed spy has extra calls beyond the ones being ordered.

db.connect()
db.query('a')
inOrder.strict(db.spy.connect, db.spy.query)   // ✓

db.connect()
db.query('a')
db.connect()
inOrder.strict(db.spy.connect, db.spy.query)   // ✗ — extras break the interleave

Use .strict when you want to assert exactly the listed sequence happened with no interleaving on the listed spies.

How ordering is determined

Every CallRecord carries a monotonic sequence number assigned at invocation time (via a module-level counter). inOrder reads each entry's sequence and checks strict ascending order against the argument order.

• Sub-millisecond resolution. Two calls in the same tick get different sequences.
• Per-worker scope. Vitest workers each load their own module copy, so the counter is per-worker.

See also

• Cross-mock ordering guide — worked examples and patterns
• Types — MethodSpy, CallRecord