BREAKING CHANGE: cereale moves from legacy `experimentalDecorators` to TC39
standard decorators, which is what makes validation rules type-checked against
the fields they are attached to.
class User {
@IsString() name!: string; // fine
@IsString() age!: number; // Type 'number' is not assignable to 'string'
}
Legacy decorators receive (target: any, key: string) and lose the field type
entirely, so this was impossible in v1. Standard decorators receive
ClassFieldDecoratorContext<This, Value>, which carries it. Rules now checked:
scalar rules against scalar fields; { each: true } against arrays, in both
directions; @JsonType against the field's class; @JsonSerialize/@JsonDeserialize
against the field's type; @IsIn and @IsEnum against the field's value type.
17 tests invoke the real compiler to assert the wrong code stays rejected — a
guarantee nobody checks is one that quietly stops holding.
Positioning follows the capability: validated domain objects, not validated
data. The README now leads with the Zod comparison. Cereale does not infer your
type from a schema — you still write the field type and the rule — but it
guarantees the two cannot disagree, which is what class-validator never offered.
Removed
- metadata-storage.ts and its WeakMap singleton. Metadata lives on
context.metadata now, which also removes the dual ESM/CJS double-singleton
hazard. Inheritance merging becomes structural rather than reconstructed on
every read, so the subclass-shadowing defect fixed by hand in 0.1.0 cannot
reoccur by construction.
- registerDecorator, replaced by defineRule(Class, 'field', constraint).
Unchanged: the engine, options, naming strategies, access control, error
helpers, the sync API, and the performance work. 193 tests pass.
Toolchain note: standard decorators are transformed by tsc and esbuild, but not
yet by oxc. The library builds with tsc and consumers on esbuild/Vite are fine;
Vitest 4 uses oxc, so the test runner needs an esbuild transform plugin. This is
recorded in vitest.config.ts and the README, and is the reason 1.x should stay
available for oxc-based toolchains.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SAcqrz3FcadkYr3xG32CjK
Rounds out the validator set with the rules an application actually reaches for,
all following the existing decorator style and honouring each/message options.
- equality and presence: @Equals, @NotEquals, @IsEmpty, @IsEnum, @IsInstance
- strings: @Length, @IsAlpha, @IsAlphanumeric, @IsNumberString, @IsLowercase,
@IsUppercase, @Contains, @NotContains, @StartsWith, @EndsWith
- formats: @IsUUID, @IsJSON, @IsDateString, @IsSemVer, @IsHexColor, @IsIP
- numbers: @IsDivisibleBy, @IsPort, @IsLatitude, @IsLongitude, @IsBigInt
- dates: @MinDate, @MaxDate
- arrays: @ArrayUnique, @ArrayContains, @ArrayNotContains
@ValidateIf(o => ...) makes a property's rules conditional on the rest of the
object, and @Allow() declares a property that needs no rules of its own so it
survives unknownKeys: 'strip'.
Two details worth noting. @IsEnum filters the reverse mapping a numeric enum
compiles to, so 'Low' is not accepted as a value of enum { Low, High }.
@MinDate/@MaxDate accept a thunk, so "not in the past" is evaluated per
validation instead of being frozen when the class was declared.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SAcqrz3FcadkYr3xG32CjK
Claude