Sample
superjson 2.2.6: Observe how superjson's metadata format versioning (meta.v), deduplication mode, in-place deserialization, and registry keying alter serialization behavior silently across boundaries
Verified sample for npm superjson 2.2.6: Observe how superjson's metadata format versioning (meta.v), deduplication mode, in-place deserialization, and…
sha256:e6cb64b107388f3fa051f1da09fd44d009cf211ada6b133e516d380c798ce68a
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
node linux x64 node node npm
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-16 |
| node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
Case
HOW- Goal
- Observe how superjson's metadata format versioning (meta.v), deduplication mode, in-place deserialization, and registry keying alter serialization behavior silently across boundaries
- Packages
- Symbols
-
- superjson.serialize
- superjson.deserialize
- superjson.stringify
- superjson.parse
- superjson.registerSymbol
- superjson.registerClass
- superjson.registerCustom
- SuperJSON
- SuperJSONResult.meta
- Environment
- node
- Created
- 2026-08-16T06:23:09Z
Contract
- assert meta.v is 1 in modern superjson and escapes dots with backslashes so dotted keys round-trip intact
- assert unversioned or legacy meta.v < 1 payloads silently misroute dotted paths to nested sibling properties, leaving the top-level key as a string and creating an Invalid Date without throwing
- assert deserialize defaults to inPlace: false via a deep clone leaving the input payload untouched, whereas inPlace: true directly mutates payload.json into live runtime objects
- assert parse uses inPlace: true internally on the parsed JSON tree rather than cloning
- assert dedupe: false preserves full duplicate structures in json while annotating referential equalities, allowing non-superjson consumers to read the payload
- assert dedupe: true replaces duplicate object instances with null in json, causing silent data loss for plain JSON consumers while superjson restores referential equality
- assert circular references write null at the cycle point and restore referential equality on deserialization in both modes
- assert registerSymbol without an explicit identifier keys by description, so registering two distinct symbols with identical descriptions silently causes the second to overwrite the first upon deserialization
- assert registerClass with allowProps silently strips any unlisted properties from the serialized JSON payload
- assert registerCustom does not recursively walk the returned structure, treating its output as a terminal leaf and leaving inner types unannotated
- assert superjson strictly forbids prototype pollution keys (__proto__, constructor, prototype) by throwing during serialization, unlike standard JSON.stringify
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- src/boundaries.mjs
- test/contract.mjs