prost-helpers

This crate provides a derive macro prost_helpers::AnyPB for every prost generated message. It automatically generates getter methods:

For optional fields, the getter methods return Result and thus can be used to simplify Option handling boilerplate code.
For enum fields, the getter methods can help cast i32 to the enum type. It also checks the zero value of the enum, which actually means the enum field is not present.
For other kinds of fields, the getter method is the same as field access.

An example of the generated getter methods:

rust

#[derive(prost_helpers::AnyPB)]
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct FooMessage {
    #[prost(message, optional, tag="1")]
    pub field: ::core::option::Option<Field>,
    #[prost(enumeration="foo_message::EnumFieldType", tag="2")]
    pub enum_field: i32,
    #[prost(uint32, tag="3")]
    pub uint32_field: u32,
    #[prost(uint32, optional, tag="4")]
    pub optional_uint32_field: ::core::option::Option<u32>,
    #[prost(message, repeated, tag="5")]
    pub repeated_field: ::prost::alloc::vec::Vec<Field>,
}

impl FooMessage {
    pub fn get_field(&self) -> Result<&Field> {
        self.field
            .as_ref()
            .ok_or_else(|| crate::ProstFieldNotFound(stringify!(field)))
    }

    pub fn get_enum_field(&self) -> Result<foo_message::EnumFieldType> {
        if self.enum_field.eq(&0) {
            return Err(crate::ProstFieldNotFound(stringify!(enum_field)));
        }
        foo_message::EnumFieldType::from_i32(self.enum_field)
            .ok_or_else(|| crate::ProstFieldNotFound(stringify!(enum_field)))
    }

    pub fn get_uint32_field(&self) -> u32 {
        self.uint32_field
    }

    pub fn get_optional_uint32_field(&self) -> Result<&u32> {
        self.optional_uint32_field
            .as_ref()
            .ok_or_else(|| crate::ProstFieldNotFound(stringify!(optional_uint32_field)))
    }

    pub fn get_repeated_field(&self) -> &Vec<Field> {
        &self.repeated_field
    }
}