Crate protovalidate_buffa 

Runtime companion for protoc-gen-protovalidate-buffa.

Provides the Validate trait, the ValidationError / Violation / FieldPath types returned from generated validate() methods, the cel module of thin helpers that compile-time-expanded CEL rules call into (scalar widening, Duration/Timestamp converters, now), and the rules module of pure-Rust helpers used by generated code (UUID / ULID / IP / URI / hostname checks and friends, mostly thin wrappers over uuid, ulid, ipnet, and fluent-uri).

There is no CEL interpreter at runtime: the paired protoc-gen-protovalidate-buffa plugin transpiles every CEL rule to native Rust at codegen time. Generated validate() methods are direct field-access checks with zero per-call Value / HashMap allocations.

ValidationError carries three orthogonal signals:

• violations: list of per-field rule failures (the common case).
• compile_error: non-empty when the codegen plugin detected a schema-level mismatch (rule type / field type, duplicate / unknown fields in message.oneof, CEL referencing a non-existent field).
• runtime_error: non-empty when a rule’s precondition could not be evaluated (e.g. bytes.pattern on non-UTF-8 input, or a CEL rule that compiled-time analysis flagged as always-runtime-error such as dyn(this).<unknown_field>).

The full upstream protovalidate-conformance suite (2872 cases, covering proto2, proto3, and editions 2023) passes against code emitted by the paired plugin.

Re-exports

pub use buffa;

pub use regex;

Modules

cel

Helpers used by compile-time-expanded CEL rules emitted by the plugin.

rules

Macros

field_path

Structs

FieldPath

FieldPathElement

ValidationError

Violation

Enums

FieldType

Subscript

Traits

Validate

Attribute Macros

connect_impl

#[connect_impl] — attribute macro applied to a Connect service impl block that inserts req.validate()? at the top of every handler method. Guarantees protovalidate runs for every RPC without relying on per-handler discipline.