Definition of done

A Foundation change is complete when one shared meaning remains portable across all consumers that serialize, fingerprint, migrate, or branch on it. Passing a local unit test is necessary; it is not cross-package compatibility evidence.

Completion gate

Changed contract	Required evidence	Consumer consequence to inspect
identifier	valid and invalid construction, normalization, equality, and round trip	caches, references, and joins retain identity
result, failure, or refusal	exhaustive state construction and serialization	callers do not collapse refusal, failure, and absence
canonical JSON	byte-stable ordering and supported-value round trips	fingerprints and retained artifacts remain reproducible
document schema	validation, version field, and representative old/new documents	readers reject or accept the same document classes deliberately
schema migration	source-version fixture, target-version result, idempotence policy, and unsupported path	no consumer guesses how to cross a version boundary
fingerprint or stable value	deterministic fixture and semantic-change case	equal meaning hashes equally; changed meaning cannot reuse identity
public export	API guard and import-boundary proof	consumers have one supported import route

Contract travel

flowchart LR
    S["shared contract change"] --> L["Foundation proof"]
    L --> Z["serialization and migration proof"]
    Z --> C["affected consumer proof"]
    C --> A{"same meaning everywhere?"}
    A -->|yes| D["complete"]
    A -->|no or unknown| B["blocked"]

Start with the focused suites under tests/identity, tests/outcomes, tests/serialization, and tests/compatibility. Public exports and dependency direction are protected under tests/package. Then run the tests of every package whose stored or public contract consumes the changed meaning.

Completion record

Record the contract family, old and new serialized forms when applicable, migration direction, affected consumers, and exact checks. If no prior fixture exists, state that compatibility is unproven; do not infer it from successful construction of the new type.

Not complete

The change remains incomplete if two versions can be read but their semantic difference is undocumented, if a migration mutates provenance silently, if a new export bypasses the public API, or if downstream packages are expected to adapt through duck typing. Shared meaning must move by an explicit contract.