示例

superjson 2.2.6: See exactly what JSON.stringify destroys about a Date, Map, Set, BigInt, undefined, NaN, Infinity and RegExp, and which of them superjson puts back

已验证示例 — npm superjson 2.2.6: See exactly what JSON.stringify destroys about a Date, Map, Set, BigInt, undefined, NaN, Infinity and RegExp, and which of them…

sha256:97bbd6c4d7adf8fafd6021c2aa3a67ab2229cb30314cdd2e7106ba36b77a7316

MIT-0

执行证据

声明的环境与签名的运行分开呈现，你可以看到这个样本究竟运行了什么、在哪里运行。

证据依据: 签名契约通过
验证回执: 2
构建过它的签名密钥: 2

声明的环境 node 22 linux x64 node 22 javascript npm

验证运行环境

环境	契约	阶段	运行日期
node 22 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243	PASS	compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1	2026-08-14
node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9	PASS	compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1	2026-08-18

案例

HOW

目标: See exactly what JSON.stringify destroys about a Date, Map, Set, BigInt, undefined, NaN, Infinity and RegExp, and which of them superjson puts back
包: superjson 2.2.6
符号: superjson.stringify
superjson.parse
superjson.serialize
superjson.deserialize
superjson.registerClass
superjson.allowErrorProps
SuperJSONResult.meta
JSON.stringify
环境: node 22
创建时间: 2026-08-14T13:20:21Z

契约

assert JSON.stringify throws a TypeError reading exactly "Do not know how to serialize a BigInt", naming no key, so one BigInt takes the whole document down
assert every other loss is silent: JSON.stringify succeeds and turns the Date into a string that is no longer a Date
assert Map, Set and RegExp all come back as {} from JSON.stringify, because their contents live in internal slots and only enumerable own properties are walked
assert NaN and Infinity both become null, arriving indistinguishable from each other and from a real null
assert the asymmetry: the same undefined is deleted from an object but coerced to null inside an array, so a record and a list do not survive the same round trip
assert JSON.stringify(undefined) returns the value undefined rather than a string, so sending it directly sends invalid JSON
assert superjson round-trips the whole fixture back to its own types: Date, Map, Set, bigint and RegExp, with NaN, Infinity and the exact 2^53+1 bigint value intact
assert Number() on that bigint silently returns 2^53, which is why the throw exists and why the obvious workaround is wrong
assert a Map keeps non-string keys, while the hand-rolled Object.fromEntries fix stringifies a number key and collapses an object key onto "[object Object]"
assert both halves of the undefined asymmetry are repaired: the object key exists again and the array slot holds a real undefined rather than a hole
assert restoration rebuilds rather than aliases, so the returned Date is a new object with the same instant
assert nesting is not special-cased: a Date inside an array inside an object, and a Date held as a Map value, both come back
assert negative zero survives superjson but not JSON.stringify, by the same route as NaN and Infinity: tagged "number" and carried as the string "-0"
assert serialize returns exactly {json, meta}, with json being ordinary JSON that JSON.stringify accepts, and a rebuilt tree that does not alias the input
assert meta.values is one dotted-path entry per rebuilt value with the tags Date, map, set, bigint, undefined, number and regexp, that the casing of a tag is not derivable, and that meta.v is 1
assert URL is a second capitalised tag that superjson restores, and that plain JSON.stringify flattens a URL to its href because URL has a toJSON of its own, so toJSON is not Date-specific
assert a path segment containing a dot is escaped in the meta key and that such a key round-trips intact
assert meta is absent entirely rather than empty when nothing needed annotating, so reading result.meta.values on plain data throws
assert reaching one object by two paths brings meta back on its own with referentialEqualities and no values, keyed by identity rather than by value, and that the annotation re-links the two copies so x === y survives the round trip
assert deserialize takes the split back as an object, so the two pieces can travel separately
assert stringify is exactly JSON.stringify of the split, and that a bare undefined becomes valid JSON here unlike JSON.stringify
assert an unregistered class instance keeps its data, loses its prototype and methods, and is not annotated at all
assert a function is left in json by serialize as a live reference and is only dropped by the JSON.stringify inside stringify, so json is typed JSONValue but is not always a JSON value
assert an unregistered symbol value takes that same two-step path, and that plain JSON.stringify drops a symbol the same asymmetric way it drops undefined
assert an Invalid Date is NOT restored: it is unannotated, passed through into json, then turned into null by Date.prototype.toJSON at the stringify step
assert a TypeError comes back as a plain Error with the stack dropped, while JSON.stringify reports any Error as {} because message and stack are own but non-enumerable and name is not an own property
assert the subclass survives only as data: the tag is the capitalised "Error" for every Error and the name string is reassigned onto a base Error, so err.name still reads TypeError while instanceof TypeError is false
assert the dropped stack is opt-in rather than policy: allowErrorProps('stack') on a private instance carries it through stringify and parse, while the default instance measured above does not
assert registerClass restores instanceof and methods and annotates the value as ["class", name]
assert deserializing a class name this end never registered throws rather than degrading to a plain object
assert registerClass mutates the singleton shared by every importer of the default export, while a private SuperJSON instance keeps its own registry

文件

csx.json
package-lock.json
package.json
src/roundtrip.mjs
test/contract.mjs

下载源代码构件 (tar.gz)

原始种子者

anonymous