Profiling the validator showed roughly half of all validation time re-deriving
answers that cannot change — collectConstraints 22%, getOwnMetadata 12%,
getMetadataChain 9%, getProperties 4%, getMetadata 3%, plus 8% GC from the
allocation churn. The constraint predicates themselves were under 1%.
Decorator metadata is fixed once classes are declared, so the derived structures
are now memoized per prototype: the validation plan, the serialization plan, the
deserialization plan, and serializer/deserializer instances, which were being
constructed fresh for every property of every object. MetadataStorage carries a
version counter that invalidates the caches when metadata is written, so
registerDecorator after first use still works — covered by a test.
Measured against JSON.parse + JSON.stringify as a fixed reference:
validate (50 orders) 221.6 us -> 49.6 us 4.5x
validate (10 orders) 47.8 us -> 12.9 us 3.7x
toInstance (50 orders) 255.1 us -> 74.0 us 3.4x
toInstance (10 orders) 64.6 us -> 19.0 us 3.4x
toPlain (50 orders) 294.4 us -> 95.3 us 3.1x
Reliability, in the same pass:
- maxDepth option (default 64) on every mapping function, on validate(), and on
configure(). All three engines recurse, so a payload nested thousands of levels
deep could exhaust the call stack. Cycles were already handled; legitimate deep
nesting was not bounded.
- each: true failures now name the element that failed ("failed at index 3"). A
bad entry in a 200-item array previously produced a message that could not
locate it. A message function now receives the failing element as args.value
rather than the whole array; caller-supplied strings stay verbatim.
150 tests (up from 136), all green on the existing suite unchanged.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SAcqrz3FcadkYr3xG32CjK
The README described a library that did not exist in places. It showed
@ValidateNested({ each: true }), which did not compile; told users to enable
emitDecoratorMetadata, which the library never reads; and documented none of the
mapping API. Its Quick Start now runs verbatim — verified by compiling and
executing it against the local source.
- README: document field-name mapping, access control, options, error helpers
and the 30 new validators; drop the emitDecoratorMetadata instruction; add a
Notes and Limitations section covering circular references, validate() on
plain objects, and the fact that @JsonProperty stops the original name from
being accepted unless you add @JsonAlias
- CHANGELOG.md: new, covering 0.1.0
- example.ts: rewritten as a tour of the current API — read-only ids, write-only
secrets, renamed fields, conditional validation, flattened errors, and a
base-class rule reaching a subclass
- docs: the playground hand-listed its symbol table in three parallel places and
exposed IsEmail, which is not an export. It now derives scope from the bundle,
so new decorators work there as soon as they ship. Bundle regenerated
- version 0.1.0
136 tests, 97% statement and 100% function coverage.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SAcqrz3FcadkYr3xG32CjK
Claude