validart 2.1.0

A type-safe validation library for Dart, inspired by Zod. Supports parse/safeParse, transforms, coercion, schema composition, and structured errors.

Changelog

2.1.0 - 2026-05-01

Changed

• V.string().url() accepts schemes: const {} (scheme-optional mode) and hostOnly: true (reject path/query/fragment). Default behavior is unchanged: schemes: null keeps the existing {http, https}-required validation. Passing schemes: const {} makes the scheme optional — bare hosts (google.com, www.google.com, localhost:8080) and any well-formed scheme://host (https://x.com, ftp://x.com) both pass. Independently, hostOnly: true rejects anything past the host:port, useful for "domain field" inputs that should never accept a path. Host validation also tightened across all modes: standard labels separated by dots with a TLD of 2+ alphabetic characters, OR the literal localhost, plus an optional :port. The previous regex ([^\\s/$.?#].[^\\s]*) accepted hosts like _under_score.x and -leading.com that no DNS resolver would accept; those now correctly fail.

Added

• V.string().domain() — shortcut for "host only, no scheme, no path". Accepts bare domains (google.com, www.example.com, api.v2.example.co.uk), localhost, and optional :port; rejects scheme prefixes (https://google.com), path / query / fragment (google.com/foo, google.com?x=1), and malformed hosts. Emits its own error code VStringCode.domain ('string.domain' → 'Invalid domain') so the message matches the user's intent — for full URLs, keep using .url(...). Implemented as DomainValidator delegating to UrlValidator(schemes: const {}, hostOnly: true) plus an early-return that rejects any input containing ://.
• VArray<T>.distinct(by:) — uniqueness by an extracted key. Use it for arrays of Map / class instances where == on the elements themselves is meaningless. The by extractor is required (without one, use .unique()); duplicates are detected by collecting by(elem) into a Set. Emits the same error code as unique() (array.unique) since the failure mode is identical. Inspired by lodash.uniqBy and SQL DISTINCT.
• VObject<T>.partial() — mirrors VMap.partial(). Returns a new VObject<T> where every declared field's validator is wrapped so null is accepted in addition to the original shape; non-null inputs still run the original validator. Preserves all pipeline state (entity-level rules, when / whenMatches, preprocessors, nullable, defaultValue). Useful for partial-update DTOs where the type still has every field but only a subset is required at the API boundary, removing the need to sprinkle .nullable() on every field(...) call. The README note that previously said partial() was unavailable on VObject was rewritten — strict() and passthrough() remain unavailable (they assume a runtime-shapeable container, which VObject<T> is not).
• VObject<T>.fieldIf(condition, name, extractor, validator) — same as field(...) when condition is true, no-op otherwise. Lets the fluent chain stay unbroken when declaring a field is conditional on a flag known at the call site (feature toggle, request context, partial-update DTO). VMap doesn't need an equivalent because Dart map literals already accept if (cond) 'key': validator.
• VMap.whenMatches(condition, dependsOn:, then:) and VObject<T>.whenMatches(condition, dependsOn:, then:) — predicate-based conditional validation, sibling of the existing when(field, equals:, then:) (which is left untouched). Use it when a single literal equals is not enough: the trigger depends on a comparison other than == (>, oneOf, ...) or on the combined value of multiple fields. The predicate receives the raw input (Map<String, dynamic> for VMap, T for VObject<T>) and runs at the same pipeline step as when — failures inside then contribute to failedFieldPaths and gate later refine(dependsOn:) rules. dependsOn is required (forces explicit declaration of the fields the predicate reads, so _knownKeys() can validate them and downstream refine(dependsOn:) keeps working). The predicate itself is always synchronous; validators inside then may be sync or async — a whenMatches whose then contains an async validator opts the schema into async mode (hasAsync == true). VObject is strict (every key in dependsOn and then must already be declared via .field(...)); VMap follows the same liberal rule as when for then keys (they enter _knownKeys automatically, so subsequent refine(dependsOn: {<thatKey>}) works without further setup). Read-only snapshot exposed via whenMatchesRules getter on both types. Pinned by pipeline_contract_test.dart::whenMatches contract.
• applyIf(condition, builder) extension on every VType. Conditional schema construction at build time (not at validation time): when condition is true, returns builder(this); otherwise returns the receiver unchanged. The generic <V extends VType> preserves the receiver's concrete type, so the fluent chain keeps working (V.string().applyIf(...).email() still returns VString). Designed for parametrizing schemas from external flags (a feature toggle, a request context) without duplicating the schema body. For an else-branch, chain a second applyIf with the negated condition. Lives in lib/src/extensions/apply_if.dart, exported from package:validart/validart.dart.

2.0.0 - 2026-04-25

Fixed

• preprocess(...) / preprocessAsync(...) now actually run on every container type. All container schemas — VMap, VArray, VObject, VEnum, VLiteral, VUnion, VTransformed (and its async counterpart VTransformedAsync) — previously overrode safeParse / safeParseAsync without invoking the base-class preprocess loop, silently dropping any .preprocess(fn) / .preprocessAsync(fn) registered on them. Only primitives (VString, VInt, VDouble, VBool, VDate) ever honored preprocessors. Every container now applies sync and async preprocessors before _resolveNull, so V.map({...}).preprocess((raw) => normalize(raw)) and every analogous call transforms the input exactly like it does on primitives. Regression tests were added in test/src/types/{map,array,enum,literal,union,object}_test.dart and test/src/features_test.dart so the bug cannot return silently.
• refine(...) now runs on VLiteral, VUnion and VTransformed / VTransformedAsync. Each of these overrode safeParse and returned VSuccess(value) directly on match instead of routing through _runPipeline(value), so any .refine(fn) / .refineAsync(fn) step was silently dropped. The overrides now delegate the final success path to _runPipeline (or _runPipelineAsync), which also makes add() custom validators and chained transforms downstream of the fix work as documented.
• VTransformed<I, O> and VTransformedAsync<I, O> honor their own nullable() / defaultValue(O). Previously the wrappers only consulted the inner schema's null-handling, so V.string().transform<int>((s) => s.length).defaultValue(0).parse(null) failed with string.invalid_type because 0 was forwarded to the inner VString. The wrappers now short-circuit on null input when _hasDefault or _isNullable is set on the wrapper itself — default goes through _runPipeline as the transformed output O, and nullable returns VSuccess<O?>(null) directly. Inner-nullable behavior (.nullable().transformAsync(...)) is preserved because the wrapper still delegates when it has no own null-handling set.
• Pipeline contract test suite (test/src/pipeline_contract_test.dart). Iterates every concrete VType subclass and asserts that preprocess, preprocessAsync, refine, refineAsync, nullable(), defaultValue() and the combination of all of them behave correctly. Adding a new VType subclass now requires one call to _runPipelineContract<T>(...) — a subclass that forgets to run the base-class preprocess loop (or to route success through _runPipeline) fails the contract immediately.
• VMap.partial() now preserves pipeline state from the base schema. It previously built a fresh VMap(partialSchema) from scratch, silently dropping any refine / equalFields / refineField / add / when / strict / passthrough / nullable / defaultValue / preprocessor declared before the call — diverging from extend / merge / pick / omit, which all carry those over via _copyMapStateTo. partial() now does the same, so a base schema's entity-level rules survive the conversion to a patch schema. Pinned by test/src/integration_scenarios_test.dart::partial() + dependsOn.
• Entity-level validators with declared field dependencies now run even when unrelated fields fail. equalFields(a, b) (declares {a, b}) and refineField(check, path: 'x') (declares {x}) previously short-circuited if any field had errors; they now run as long as their declared dependencies passed, and their result is aggregated alongside field errors in a single VFailure. Generic refine(check) without dependsOn keeps the conservative behavior — it still skips when any field error exists, since it lacks the metadata to know which fields it depends on. VArray.refine is unchanged (VArray does not have entity-level dependencies). when rules continue to be evaluated as part of field-level validation.
• VEnum.safeParse and VLiteral.safeParse now throw VAsyncRequiredException when the schema has any async step. Previously, both overrides skipped the hasAsync gate that every other container honors, so calling validate / parse (sync) on V.enm(Color.values).refineAsync(...) or V.literal('admin').preprocessAsync(...) silently ran only the sync portion of the pipeline — _runPipeline does not iterate _AsyncValidatorStep, so the async refine was dropped on the floor and the schema returned true/VSuccess regardless. The gate now fires consistently across VString / VInt / VDouble / VBool / VDate / VArray / VMap / VObject / VUnion / VTransformed / VEnum / VLiteral, and the new pipeline_contract_test.dart cases for runPreprocessors exercise the path on every concrete VType.

Added

• VFailure.rootMessages() — returns the messages of every error with an empty path (root-level errors, typically emitted by refine / equalFields applied directly on a schema root). toMap() is field-keyed and intentionally excludes those errors so they cannot leak into a UI's per-field display under a fake key; rootMessages() is the explicit channel for retrieving them as a List<String> to render in a form-wide banner. The two methods partition the errors cleanly: every error appears in exactly one of toMap() or rootMessages(). Documented in the README under Form Errors → Root-level errors via rootMessages().
• refine(check, dependsOn: {'a', 'b'}) on VMap and VObject. Optional parameter that declares which schema field keys this refine depends on. When provided, the refine skips only if one of those specific keys failed validation, and runs (aggregating its error with the field errors) otherwise. Without dependsOn, the existing conservative behavior is preserved (skip on any field error). dependsOn accepts any field declared in the base schema or in any when.then block; an AssertionError is thrown for unknown keys. Same parameter on refineAsync. Built-in equalFields and refineField use this internally to declare their dependencies ({a, b} and {path} respectively), so they automatically aggregate alongside unrelated field errors. The internal add(validator, dependsOn:) parameter is also exposed so external packages can plug in custom entity-level validators with declared deps.
• VObject<T>.array() — fluent helper that returns VArray<T>, mirroring VMap.array(). Enables SignInDto.schema.array().min(1).unique() for List<T> validation without breaking the chain.
• VObject<T>.equalFields(fieldA, fieldB, {message}) — cross-field equality check, mirroring VMap.equalFields. Canonical use case is DTO password confirmation. Emits the new error code VObjectCode.fieldsNotEqual ('object.fields_not_equal') with default template '{field} must be equal to {other}', customizable per-call via message: or globally via VLocale({'object.fields_not_equal': '...'}). Throws AssertionError if either field name is not declared on the schema (uniform across all entity-level rules: equalFields, refineField, refine(dependsOn:)). Backed by a new internal ObjectEqualFieldsValidator<T>.
• VObject<T>.when(field, equals:, then:) — conditional validation, mirroring VMap.when. When the value read from field equals equals, every validator in then is applied to the corresponding field in addition to its baseline validator. Asserts that field and every key in then are declared on the schema. Propagates through hasAsync and safeParseAsync when any then validator is async.
• VObject<T>.refineField(check, path:, message:) — entity-level predicate scoped to a specific field path. The check receives the whole T instance (so it can compare across fields), and the emitted error's path is [path]. Mirrors VMap.refineField but without the string-keyed lookup.
• VObject<T>.pick(List<String>) / .omit(List<String>) — derive a new schema containing only / excluding the specified fields. Preserves all pipeline state (validator steps, when rules, preprocessors, nullable, defaultValue). Unlike TypeScript, the input type stays T — only the validation surface is narrowed; this is not a subset type. For partial/dynamic payloads, use VMap.partial() instead.
• VObject<T>.merge(VObject<T> other) — combine two schemas of the same T into a new one. Fields and pipeline state (validator steps, when rules, preprocessors, nullable, defaultValue) from both sides are concatenated/OR-ed. Useful for composing shared audit/meta field groups with domain-specific schemas.
• VType.runPreprocessors(value) / runPreprocessorsAsync(value) — public accessors to the preprocess stage of any schema, returning the value after the preprocess chain ran (sync chain only for runPreprocessors; sync + async, in registration order, for the async variant). Does NOT run _resolveNull, validators, or transforms — only the preprocess stage. Sync variant throws VAsyncRequiredException when the schema has any async preprocessor. Useful for downstream consumers (e.g. valiform) that need to mirror the container preprocess in their own scoped pipeline before running per-field checks. Every concrete container (VType, VMap, VObject, VArray, VUnion, VTransformed, VTransformedAsync, VEnum, VLiteral) was refactored to use these methods internally for their safeParse / safeParseAsync preprocess stage — behaviour is identical to before, only the duplicated loop is gone. Pinned by test/src/pipeline_contract_test.dart, which now asserts both methods on every concrete VType.
• VType.hasPreprocessors — true when the schema has at least one preprocessor registered (sync or async). Lets consumers gate the preprocess plumbing on actually-needed work; valiform's per-field validator uses it to skip snapshot construction entirely on schemas without container preprocess.
• VMap.refineFieldRaw(check, {path, message}) and VObject<T>.refineFieldRaw(check, {path, message}) — entity-level rules scoped to a field path that run before any per-field iteration. The callback receives the raw input (Map<String, dynamic> for VMap, T for VObject<T>) — each field still as it arrived from the input, no field-level preprocess / validators / transforms applied yet. Compare with refineField, whose callback runs after the full per-field pipeline (and whose dependsOn is implicitly {path}); refineFieldRaw has no dependsOn because no field has been validated yet, so it always runs once the type check succeeds. Error path is [path] (mirrors refineField) so consumers like valiform's VForm surface it inline under the target field. Use refineFieldRaw when the rule depends on the input as the user typed it (raw casing, whitespace, pre-coercion shape); reach for refineField for everything else. Backed by a new _RawValidatorStep<T> and a public VType.addRaw(...) low-level API. Documented in README → Cross-Field Validation.
• Factory-level invalidTypeMessage: parameter. Every factory (V.string(), V.int(), V.bool(), V.date(), V.map(), V.array(), V.object(), V.enm(), V.literal(), V.union()) now accepts an optional invalidTypeMessage: that customizes the invalid_type error fired when input is non-null but has the wrong runtime type (e.g. 42 against V.string()). It coexists with the existing message: (which still scopes only to the required error on null input) — set one, the other, or both. Mirrors Zod's required_error / invalid_type_error separation; required is typically a user-facing label, invalid_type is a developer-facing signal, so keeping the channels separate avoids one polluting the other. The error code is unchanged (string.invalid_type, int.invalid_type, ...); only the message text is replaced when set. Without invalidTypeMessage:, the locale template 'Expected {expected}, received {received}' is preserved verbatim. VEnum and VLiteral accept the parameter for API uniformity but the override never fires there — they emit enum.invalid / literal.invalid codes instead of invalid_type.

Changed

• Breaking — VObject now uses a fluent .field() API instead of the configure: callback builder. The VObjectBuilder<T> class and the configure: named parameter on both V.object<T>(...) and VObject<T>(...) were removed. Field extractors are now chained directly on the schema with the same .field(name, extractor, validator) signature, identical to the rest of the library (V.string().email().min(5)). Before: V.object<User>(configure: (o) => o.field('name', (u) => u.name, V.string()).field('age', (u) => u.age, V.int())); After: V.object<User>().field('name', (u) => u.name, V.string()).field('age', (u) => u.age, V.int());. Migration: drop configure: (o) => and the o. prefix — the rest of the chain is unchanged. Enables the static final DTO pattern: class SignInDto { static final schema = V.object<SignInDto>().field(...).field(...); }, so the schema is built once per isolate and reused without re-wrapping it in V.object<X>(...) at every call site.

1.3.0 - 2026-04-23

Added

• V.coerce.date() now accepts the same default formats as V.string().date() — ISO 8601 (YYYY-MM-DD and variants with time), BR (DD/MM/YYYY), US (MM/DD/YYYY), EU (DD.MM.YYYY), dashed (DD-MM-YYYY, MM-DD-YYYY), compact (YYYYMMDD), slashed (YYYY/MM/DD). Calendar-invalid dates (like 30/02/2024) continue to throw. Parsing logic moved to a shared helper (lib/src/utils/date_parser.dart) used by both DateStringValidator and VCoerce.date(). For strict format validation, chain V.string().date(format: '...') before coercion.

Changed

• Breaking — V.string().phone() / .postalCode() / .taxId() / .licensePlate() now accept a list of patterns. The parameter was renamed from pattern: (single Pattern) to patterns: (non-empty List<Pattern>), and validation succeeds when any pattern in the list matches — enabling multi-country systems to declare every accepted format in a single schema instead of wrapping multiple schemas in V.union([...]). V.string().phone() with no argument continues to default to a single E164PhonePattern (behavior unchanged). Migration: wrap any existing single pattern in a list — pattern: const UsZipPattern() → patterns: [const UsZipPattern()]. For phone, the emitted error code keeps each pattern's custom code when exactly one pattern is configured; with two or more, the generic VStringCode.phone is emitted. For postal code / tax ID / license plate, the {name} interpolation param now joins each pattern's name with / when multiple are configured — a single template like 'Invalid {name}' renders correctly in both single- and multi-pattern mode.
• Breaking — all error codes are now domain-prefixed. Every string emitted by error.code follows <type>.<action> (e.g. string.email, number.positive, int.even, bool.is_true, date.weekday, array.unique, enum.invalid). The three generic fallbacks (required, invalid_type, custom) stay flat in VCode — VLocale uses them as the backstop when a prefixed key has no match. Constants in the sealed classes keep the same identifiers (VStringCode.email, VIntCode.even, VDoubleCode.integer, etc.); only the string value each one maps to changed. Migration: find-and-replace the old flat codes in VLocale configurations and in any error.code == '...' comparisons. Highlights: 'invalid_email' → 'string.email', 'positive' → 'number.positive', 'even' → 'int.even', 'decimal' → 'double.decimal', 'is_true' → 'bool.is_true', 'weekday' → 'date.weekday', 'unique' → 'array.unique', 'invalid_enum' → 'enum.invalid'. Complete mapping table in README.
• VLocale._defaults is now structured as a nested map grouping each type's translations ('string': {'email': '...', 'too_small': '...'}). Default behavior unchanged — the _resolve fallback chain already works with flat or nested lookups. This is purely a readability improvement for maintainers; custom translations can still use either form.

Fixed

• Missing default locale templates for 14 emitted codes. The codes string.base64, string.cvv, string.hex_color, string.iban, string.json, string.mac, string.mongo_id, string.nano_id, string.semver, string.ulid, date.age, string.postal_code, string.tax_id and string.license_plate were emitted by their validators but had no matching entry in VLocale._defaults, so error.message fell through to the raw code string (e.g. "string.base64" instead of "Invalid Base64"). The default templates already documented in the README are now actually registered in VLocale. A regression test in test/src/messages/messages_test.dart ('Every emitted VCode has a default translation') iterates every VXxxCode constant and asserts a non-code default exists, so any new code added without a matching locale entry fails the suite immediately.
• Invalid SIN example in README and example/example.dart. The sample V.string().taxId(patterns: [const CaSinPattern()]).validate('046-454-286') was commented // true, but SINs starting with 0 are forbidden by CRA specification — the actual output is false. Replaced with 130-692-544 (a Luhn-valid SIN starting with a legal leading digit). All README examples with // result comments were re-verified against real output after the change.

1.2.0 - 2026-04-23

Added

• ValidationMode enum (any / formatted / unformatted) — controls whether separator-based formatting is required, forbidden, or optional on validators that accept multiple input shapes. Exported from package:validart/validart.dart.
• mode field on UsSsnPattern, UkNiNumberPattern, CaSinPattern — SSN, NINO and SIN patterns now accept a ValidationMode. Default any keeps the current behavior (modulo the change noted below for SSN).
• mode field on CaPostalCodePattern, UkPostcodePattern — Canadian and UK postal codes can now require or forbid the separating space.
• mode field on UkPlatePattern — UK plates can now require or forbid the space between the two groups.
• mode parameter on VString.card() — V.string().card(mode: ValidationMode.formatted) requires groups of four separated by spaces/dashes; ValidationMode.unformatted rejects any non-digit; ValidationMode.any (default) keeps the current behavior.
• CountryCodeFormat enum (required / optional / none) and countryCode field on E164PhonePattern — pin whether the leading + must be present, optional (default), or forbidden. Exported from package:validart/validart.dart.
• VString.integer() / VString.numeric() — validate that a string is parseable as a Dart int (decimal base) or a finite double (accepts decimal and scientific notation, rejects NaN/Infinity). Both keep the output type as String; use V.coerce.int() / V.coerce.double() when you want conversion instead. New error codes VCode.stringInteger (string.integer) and VCode.stringNumeric (string.numeric) — domain-prefixed so they can be translated independently of VCode.integer (used by VDouble.integer()).
• README i18n reference — new "Complete translation template" section in the i18n docs listing every translatable key with its default English message (including the new type-prefixed required/invalid_type entries and all interpolation tokens), ready to copy into a VLocale and translate.

Changed

• Breaking — Type-prefixed error codes for required and invalid_type. Every schema now emits its own prefixed code: VString → string.required / string.invalid_type, VInt → int.required / int.invalid_type, and so on for VDouble, VBool, VDate, VArray, VMap, VObject, VEnum, VLiteral, VUnion. The generic codes ('required', 'invalid_type') are no longer emitted at runtime but remain defined in VCode as fallback keys for translation. Code that compares error.code == 'required' must be updated to check the prefixed form or use .endsWith('.required').
• Breaking — VCode reorganized into sealed classes per type. The 60+ flat constants (VCode.stringRequired, VCode.invalidEmail, VCode.positive, VCode.even, ...) were replaced by 12 companion sealed classes — VStringCode, VNumberCode, VIntCode, VDoubleCode, VBoolCode, VDateCode, VArrayCode, VMapCode, VObjectCode, VEnumCode, VLiteralCode, VUnionCode. VCode itself now holds only the generic fallbacks (required, invalidType, custom). Migration is a mechanical rename — the strings emitted in error.code and the keys used by VLocale stay identical. Examples: VCode.stringRequired → VStringCode.required, VCode.invalidEmail → VStringCode.email, VCode.positive → VNumberCode.positive, VCode.even → VIntCode.even, VCode.age → VDateCode.age, VCode.invalidEnum → VEnumCode.invalid.
• VLocale now accepts nested overrides and falls back to the generic code. Entries can be flat ('string.required': '...') or nested ('string': {'required': '...'}), mixed in the same map. When a prefixed code has no match, lookup drops the prefix and tries the generic key — so {'required': 'Obrigatório'} still covers every schema, while {'string': {'required': '...'}} or {'string.required': '...'} narrows the override to strings only. Existing VLocale({'required': 'x'}) calls keep working unchanged.
• VType exposes typeName getter — abstract in the base class, overridden by each concrete schema (e.g. 'string', 'int'). Third-party schemas extending VType must implement it.
• Breaking (subtle) — UsSsnPattern in ValidationMode.any no longer accepts mixed shapes like 123-456789 or 12345-6789. Only fully-formatted (123-45-6789) or fully-unformatted (123456789) inputs are accepted. Users that relied on the older permissive behavior can write their own regex via a custom TaxIdPattern.

1.1.0 - 2026-04-21

Added

Async validation

• refineAsync — async custom check on any schema. Companion consumers validateAsync, parseAsync, safeParseAsync, errorsAsync run the full pipeline asynchronously. Sync consumers (validate, parse, safeParse, errors) throw the new VAsyncRequiredException when called on a schema that contains async steps — pointing callers to the async variant. Propagates recursively through VMap, VArray, VObject, VUnion, and VTransformed. Schemas without async stay 100% synchronous with no overhead.
• AsyncValidator<T> — async sibling of Validator<T> (returns Future<Map<String, dynamic>?>) with new addAsync method on every schema for plugging custom async validators. Reusable across schemas.
• preprocessAsync — async input transformation before type check.
• transformAsync<O> — async output conversion after validation (creates VTransformedAsync<I, O>).
• timeout parameter on refineAsync — exceeding it counts as a failure with the same code/message.
• VAsyncRequiredException — exception thrown by sync consumers when the schema contains async steps; includes methodName and suggestion fields.

Generic string validators

• base64 — RFC 4648 (length multiple of 4, padding with =).
• hexColor — #FFF or #FFFFFF.
• mac — MAC address with colon or dash separators (consistent within the value).
• semver — Semantic Version 2.0 including pre-release / build metadata.
• mongoId — 24-hex MongoDB ObjectId.
• iban — ISO 13616 (accepts spaces) + mod-97 check digit.
• json — string that parses via dart:convert.
• cvv — 3 or 4 digits.
• ulid — 26 chars Crockford Base32, timestamp-cap first char (0–7).
• nanoId — URL-safe [A-Za-z0-9_-], default length 21 (configurable via length).

Pluggable patterns

• PhonePattern — abstract phone-validation strategy. Built-in: E164PhonePattern (default). V.string().phone({PhonePattern? pattern, String? message}) — optional pattern; without it, behaves exactly as before.
• CardBrandPattern — abstract card-brand matcher. Built-ins: VisaBrand, MastercardBrand, AmexBrand, DinersBrand, DiscoverBrand, JcbBrand. V.string().card({List<CardBrandPattern>? brands, String? message}) — when brands is omitted/empty, any Luhn-valid number is accepted; when provided, must match at least one.
• PostalCodePattern — abstract postal-code strategy. Built-ins: UsZipPattern (12345 / 12345-6789), CaPostalCodePattern (A1A 1A1), UkPostcodePattern.
• TaxIdPattern — abstract tax-ID strategy. Built-ins: UsSsnPattern (123-45-6789), UkNiNumberPattern (HMRC prefix rules + A–D suffix), CaSinPattern (9 digits + Luhn + CRA first-digit rule).
• LicensePlatePattern — abstract license-plate strategy. Built-in: UkPlatePattern (AB12 CDE post-2001 format). Plates with heavy regional variation (US per state, CA per province) are intentionally not built in.

External packages (e.g. validart_br with CPF, CNPJ, CEP, Mercosul) can extend each abstract pattern without forking the core.

New methods / API

• VString.date({String? format, String? message}) — new optional format. When passed, the string must match that exact format (tokens: YYYY, MM, DD; any other character is a literal separator). When omitted, accepts ISO extended/basic, BR, US and EU layouts.
• VString.toPascalCase, toCamelCase, toSnakeCase, toScreamingSnakeCase, toSlug — pre-processing case transforms. Word boundaries detected across separators ( , _, -), case transitions, and digits; non-alphanumeric characters are dropped.
• keepAccents parameter on all case transformers. Default false (accents transliterated: São João → sao-joao, ç → c, ñ → n, ß → ss). Pass true to preserve.
• VDate.age({int? min, int? max, String? message}) — validates age derived from a birthdate (computed against DateTime.now() at validation time). At least one of min/max is required.
• UuidVersion enum — UuidVersion.v1 through UuidVersion.v8. V.string().uuid({UuidVersion? version, String? message}) accepts an optional version filter — e.g. V.string().uuid(version: UuidVersion.v7) for timestamp-ordered only.
• VString.url({Set<String>? schemes}) — optional schemes set. Default {http, https} (backwards compatible); pass {http, https, ftp, ws} etc. to accept other protocols.
• VString.password({String? specialChars}) — optional specialChars string. Default !@#$%^&*(),.?":{}|<> (backwards compatible); pass a custom string to expand (e.g. r'!@#$%^&*()-_+=<>?' to accept - and _).
• Factory-level message on every factory — V.string(), V.int(), V.double(), V.bool(), V.date(), V.map(), V.array(), V.object(), V.enm(), V.literal(), V.union() all accept an optional message to customize the required error per schema without changing the global locale. Example: V.bool(message: 'You must accept the terms').isTrue(). Fallback: custom → locale → default English. Same parameter name as the validator-level message (.email(message: ...), .min(n, message: ...), .refine(fn, message: ...), ...) but different scope: the factory-level one fires only on null input (pre-validation required error), the validator-level one fires only when that validator rejects a non-null value. Both can coexist on the same schema.
• hasDefault / defaultValueOrNull on every schema — read-only introspection getters on VType<T>. hasDefault returns whether a default was configured via defaultValue(x); defaultValueOrNull returns the configured value (or null when none was set). Useful for tooling and conditional logic that needs to inspect schema state without altering it.

Changed

• UuidValidator now accepts versions 1–8 (was 1–5). v6, v7 and v8 from RFC 9562 draft (including the timestamp-ordered v7 that is replacing v4 in many modern APIs) are considered valid.
• PhoneValidator delegates to a PhonePattern instead of hardcoding the E.164 regex. Backwards compatible: the default pattern preserves the previous behavior.
• CardValidator gained an optional brands constructor parameter. Backwards compatible: without brands it behaves exactly as before (Luhn + length). Cards with masks (spaces or dashes) are still accepted.
• DateStringValidator gained an optional format constructor parameter and, without it, now accepts multiple formats (ISO extended/basic, BR DD/MM/YYYY, US MM/DD/YYYY, EU DD.MM.YYYY, and dashed variants). Ambiguous strings like 02/03/2020 pass when at least one interpretation is calendar-valid.
• Breaking — defaultValue is now validated by the pipeline. When input is null and a default is set, the default is substituted for the input and runs through preprocessors, validators and refines (sync or async). Previously it short-circuited with VSuccess(default) regardless of whether the default satisfied the schema. This prevents silent bugs like V.string().defaultValue('').min(3).parse(null) returning ''. Upgrade: ensure your defaultValue(x) satisfies the chained validators.
• Breaking — DateStringValidator multi-format mode. Callers that relied on the previous ISO-only semantics need to either use date(format: 'YYYY-MM-DD') explicitly or accept that BR/US/EU strings now pass.

Fixed

• DateStringValidator now rejects calendar-invalid dates such as 2024-02-30, 2024-04-31, or 2023-02-29 that the previous regex-only implementation accepted. The validator reconstructs the date via DateTime and compares each component to guard against rollover (2024-13-01 → 2025-01-01).

1.0.0 - 2026-04-18

Complete Rewrite

Core API:

• V static class — no instantiation needed (V.string(), V.int(), V.map(), etc.)
• parse(), safeParse(), validate(), errors() on all types
• VResult<T> sealed class with VSuccess<T> and VFailure<T> (Dart 3 pattern matching)
• VError with code, message, path (nested paths like ['address', 'zip'] or [2, 'name']), and optional context (List<List<VError>>?) populated by VUnion to expose each option's failure

Types:

• VString — 22 validators + notEmpty() + pre-processing transforms (trim, toLowerCase, toUpperCase) that always run before validation
• VInt, VDouble — numeric validators (min, max, even, odd, prime, finite, etc.)
• VBool — isTrue, isFalse
• VDate — after, before, between, weekday, weekend
• VArray<T> — min, max, unique, contains + indexed error paths
• VMap — schema composition (pick, omit, extend, merge, partial, strict, passthrough) + equalFields(), refineField(), when(), whenRules, array(). extend/merge preserve pipeline state from the base (validators, when rules, strict/passthrough/nullable flags, defaultValue, preprocessors); merge concatenates rules/steps from both sides and OR-s flags
• VObject<T> — validates class/entity instances with type-safe field extraction
• VEnum<T>, VLiteral<T>, VUnion
• VTransformed<I, O> — type-changing transforms

Pipeline:

• Three-phase execution: pre-processing → validation → post-processing
• Pre-processing transforms (trim, toLowerCase, toUpperCase) always run before validators regardless of chain order

Features:

• Coercion: V.coerce.int(), V.coerce.double(), V.coerce.string(), V.coerce.bool(), V.coerce.date()
• transform<O>() — change output type with chaining support
• preprocess() — transform input before type checking; multiple calls chain in declaration order
• equalFields() — cross-field comparison (password confirmation)
• when() — conditional field validation
• refineField() — targeted cross-field validation whose error attaches to the specified field path
• VFailure.toMap() — convert errors to Map<String, String> for Flutter forms
• defaultValue(T) — provide defaults when value is null; takes precedence over nullable() when both are set
• Fluent chaining across inherited and concrete methods via covariant returns on every concrete type — e.g. V.string().nullable().email(), V.int().positive().even()

i18n:

• VLocale — Map<String, String> with {param} interpolation; asserts in debug mode when any {param} is left unreplaced
• V.setLocale() / V.t() — switch locale at runtime
• VCode — static string constants for all error codes (extensible by external packages)
• Fallback chain: custom translation → English default → code itself
• Per-validator message override bypasses locale

Architecture:

• Validators are classes extending Validator<T> in validators/{type}/ — return Map<String, dynamic>? (params, not messages)
• add() is public — external packages can extend types via Dart extensions
• part of pattern for type files sharing pipeline internals
• Zero production dependencies

Removed (from v0.x)

• Validart class (replaced by V static class)
• VMessages, VStringMessages, etc. (replaced by VLocale)
• getErrorMessage() method
• Brazilian validators (CPF, CNPJ, CEP) — to be published as validart_br package
• any() / every() combinators (replaced by VUnion and refine())

0.1.1 - 2025-02-23

Fixed

• Added missing VDate export to the package exports.

0.1.0 - 2025-02-23

Added

• ValidationMode support for:
  • .cep()
  • .cnpj()
  • .cpf()
  • .phone()
• Now, it is possible to validate formatted strings (ValidationMode.formatted) or unformatted ones (ValidationMode.unformatted).
• Improved documentation for CPF, CNPJ, CEP, and Phone, explaining how to use ValidationMode.

Changed

• Updated API to support both formatted and unformatted validation for documents and phone numbers.

0.0.4 - 2025-02-20

Added

• Implemented an assertion in VMap.refine() to ensure the provided path exists in the defined object schema.
  • This prevents referencing non-existent fields, improving validation reliability.
  • Added a test case to verify that an AssertionError is thrown when an invalid path is used.

Changed

• Updated the README with more detailed documentation and examples.
• Improved API documentation to ensure full coverage across all public elements.

0.0.3 - 2025-02-19

Added

• Introduced a new primitive validator: v.date(), allowing date-based validations.
• Implemented .prime() validator for integers to check if a number is prime.
• Added new string validators:
  • password(): Ensures password complexity.
  • jwt(): Validates JSON Web Tokens.
  • card(): Validates credit card numbers.
  • integer(): Ensures the string represents a valid integer.
  • double(): Ensures the string represents a valid double.
  • slug(): Ensures the string is a valid slug format (lowercase, hyphens, no spaces or special characters).
  • alpha(): Ensures the string contains only alphabetic characters.
  • alphanumeric(): Ensures the string contains only letters and numbers.
• Expanded test suite, achieving 100% test coverage.

Changed

• Standardized class names for greater consistency across the library.
• Improved error messages and default validation messages.
• Adjusted validation logic for maps within arrays, fixing issues with nested validations.
• Updated README.md to include detailed documentation on array validations, including .array(), .unique(), .contains(), .min(), .max(), and other related methods.
• Improved examples for string and integer array validation.

Fixed

• Resolved bugs related to map validation within arrays, ensuring proper validation behavior.

0.0.2 - 2025-02-17

Changed

• Renamed string().startsWidth to string().startsWith for consistency.
• Updated README to reflect recent changes and improvements.

Removed

• Removed .any() and .every() functions from .map() as they were not applicable.

Added

• Achieved 100% test coverage, ensuring full validation reliability.
• Added default messages for all validation types, providing a consistent error handling experience.

0.0.1 - 2025-02-16

• Initial release