Sample

Configure SuperJSON instances with dedupe, inPlace deserialization, custom transformers, allowProps and allowErrorProps, and understand how downstream consumers fail on raw deduped json, frozen payloads, or unregistered schemas.

sha256:6a06c937098f463ff019be1bc3cfd90c83df7a9d2c953b750af570fe2ea91479

Case

Goal

Configure SuperJSON instances with dedupe, inPlace deserialization, custom transformers, allowProps and allowErrorProps, and understand how downstream consumers fail on raw deduped json, frozen payloads, or unregistered schemas. HOW

Packages

superjson 2.2.6

Environment

node

Created

2026-08-16T06:23:14Z

Contract

• assert standard SuperJSON (dedupe: false) duplicates identical object references in json so non-superjson consumers receive complete data
• assert SuperJSON with dedupe: true replaces duplicate references with null in json and stores referential equality links in meta
• assert non-superjson consumers reading dedupe: true payload silently receive null for all duplicate objects
• assert both dedupe: false and dedupe: true restore referential equality (a === b) when deserialized with SuperJSON
• assert dedupe: false chooses the shortest path as representative while dedupe: true preserves the first-encountered traversal path
• assert default deserialize deep-clones json via copy-anything leaving the serialized payload unmodified
• assert deserialize with inPlace: true mutates the serialized payload in-place converting string representations directly into Date and bigint instances
• assert deserialize with inPlace: true throws a TypeError when given a frozen payload while default deserialize succeeds
• assert registerClass with allowProps strips unlisted properties during serialization and constructor does not execute on deserialization
• assert registerCustom serializes custom domain objects under a custom tag and deserializing without the registration throws
• assert registerSymbol preserves registered symbol values and deserializing an unknown symbol throws
• assert symbol-keyed properties on plain objects are silently dropped during serialization
• assert allowErrorProps includes custom error properties like code and status which are otherwise stripped
• assert objects containing __proto__, constructor, or prototype own properties throw immediately to prevent prototype pollution

Files

• NOTES.md
• csx.json
• package-lock.json
• package.json
• src/config.mjs
• test/contract.mjs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-16 · ed25519:d91480838ac982c9