How can I mock a Macro attribute in Rust

How can I mock a macro attribute when testing in Rust, is there some library to facilitate this?

For instance #[my_macro] modifies a struct applying another macro #[account()] to one of his fields, this macro doesn't exist in my library but exists in the programs which are using my macro:

// lib.rs
extern crate proc_macro;
use proc_macro::TokenStream;

mod macros;

#[proc_macro_attribute]
pub fn my_macro(args: TokenStream, input: TokenStream) -> TokenStream {
      proc_macro::TokenStream::from(quote!(
          pub struct MyModifiedStruct{
            #[account()]
            pub field1: u8
          }
      ))
}

Now how can I test my_macro without getting an error for not having the #[account()] dependency in my library?

// tests/my_test.rs

#[test]
fn test_my_macro() {
    #[my_macro]
    pub struct MyStruct{}

    let my_struct = MyStruct{field1:1} 
    assert_eq!(my_struct.field1, 1)

}

My normal approach in Python would be mocking the #[account()] attribute, but not sure how can that be done in Rust.

> My normal approach in Python would be mocking the #[account()] attribute, but not sure how can that be done in Rust.

You could implement a mock version of your #[account] attribute macro in the same proc-macro crate as #[my_macro] is defined and import it into the scope you are using #[my_macro] in:

lib.rs:

extern crate proc_macro;
use proc_macro::TokenStream;

mod macros;

#[proc_macro_attribute]
pub fn my_macro(args: TokenStream, input: TokenStream) -> TokenStream {
      proc_macro::TokenStream::from(quote!(
          pub struct MyModifiedStruct{
            #[account()]
            pub field1: u8
          }
      ))
}

#[proc_macro_attribute]
pub fn account(_args: TokenStream, input: TokenStream) -> TokenStream {
    input
}

tests/my_test.rs:

// tests/my_test.rs
use your_crate::{my_macro, account};

#[test]
fn test_my_macro() {
    #[my_macro]
    pub struct MyStruct{}

    let my_struct = MyStruct{field1:1} 
    assert_eq!(my_struct.field1, 1)

}