Errors in mock injected code are correctly pointed by compiler

[CodeSandwich]

Currently when compiler finds an error in mock injected code, it prints a message pointing to the injection annotation:

error[E0106]: missing lifetime specifier
 --> tests/mocking_regular_functions.rs:6:1
  |
6 | #[inject_mocks]
  | ^ expected lifetime parameter
  |
  = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
  = help: consider giving it a 'static lifetime

Expected behavior of compiler is pointing to place, where the error actually occurs.

Blocked until Syn 0.12: dtolnay/syn#178

[CodeSandwich]

As of writing this Syn on master branch destroys span information. Switching proc-macro2 'unstable' feature, which is supposed to help to some extent makes Syn uncompilable.

[CodeSandwich]

Current workaround: before running cargo test try to compile project witch cargo check or cargo build

[CodeSandwich]

Port to Syn 0.12 almost done, but it can't use proc-macro2's nightly feature, because rust-lang/rust#47627, so still blocked.

[CodeSandwich]

Fixed in 0.3.0