Trait hedwig::validators::prost::SchemaMatcher

pub trait SchemaMatcher<MessageType> {
    type InvalidSchemaError;
    fn try_match_schema(
        &self, 
        schema: &str
    ) -> Result<(), Self::InvalidSchemaError>;
}

This is supported on crate feature prost only.

A means of asserting that an incoming message’s schema matches a given message type’s deserialized format.

 use hedwig::validators::prost::SchemaMatcher;

 struct MyMessage {
     // ...
 }

 // SchemaMatcher has a blanket impl over closures
 let my_matcher = |schema: &str| {
     // imagine some rudimentary version check
     if schema.starts_with("messages/my-message/my-schema-")
         && (schema.ends_with("my-schema-v1.proto") ||
             schema.ends_with("my-schema-v2.proto")) {
         Ok(())
     } else {
         Err(format!("incompatible schema: {}", schema))
     }
 };

 assert_eq!(
     Ok(()),
     SchemaMatcher::<MyMessage>::try_match_schema(
         &my_matcher,
         "messages/my-message/my-schema-v2.proto"
     )
 );

 assert_eq!(
     Err("incompatible schema: messages/my-message/my-schema-v3.proto".to_owned()),
     SchemaMatcher::<MyMessage>::try_match_schema(
         &my_matcher,
         "messages/my-message/my-schema-v3.proto"
     )
 );

Associated Types

type InvalidSchemaError

The error returned when a given schema does not match the message type

Required methods

fn try_match_schema(&self, schema: &str) -> Result<(), Self::InvalidSchemaError>

Check whether messages with the given schema are valid for deserializing into the trait’s generic message type.

Returns an error if the schema does not match

Implementors

impl<T> SchemaMatcher<T> for ExactSchemaMatcher<T>

type InvalidSchemaError = SchemaMismatchError

impl<T, F, E> SchemaMatcher<T> for F where
    F: Fn(&str) -> Result<(), E>, 

type InvalidSchemaError = E