Fixing dependency leaks finally

example_package/Cargo.toml

@@ -4,19 +4,12 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-# This is what we need for using this package in our mono-repo
-roslibrust = { path = "../roslibrust" }
-# Normally you would have: roslibrust = "0.7"
-# TODO in the current state of this example, we don't actually need roslibrust
-# These dependencies are needed by the code that roslibrust_codegen autogenerates
-# They are silently "leaked dependencies of the crate"
-# See https://github.com/Carter12s/roslibrust/issues/72 for resolution path
-serde = "1.0"
-smart-default = "0.7"
+# The code generated by roslibrust_codegen has dependendencies
+# We need to depend on the crate at build time so that the generate code has access to these dependencies
 roslibrust_codegen = { path = "../roslibrust_codegen" }
 
 [build-dependencies]
-# We depend on codegen as a build dependency as we (should) only need it to generate our types
+# We depend on codegen as a build dependency as we invoke it in build.rs
 roslibrust_codegen = { path = "../roslibrust_codegen" }
 # This crate is very helpful for build.rs files but not required
 cargo-emit = "0.2"

roslibrust_codegen/Cargo.toml

@@ -25,6 +25,11 @@ syn = "1.0"
 tokio = { version = "1.0", features = ["time", "signal"], optional = true}
 walkdir = "2.3"
 xml-rs = "0.8"
+# Not a direct dependencies of the crate, but something generated code uses
+# We include them as dependencies here and expose them with a `pub use`
+# So that the generate code can find them, and users don't have to added dependencies themselves
+smart-default = "0.7"
+serde-big-array = "0.5"
 
 [dev-dependencies]
 env_logger = "0.10"

roslibrust_codegen/src/gen.rs

@@ -10,17 +10,14 @@ use crate::{bail, Error};
 use crate::{ConstantInfo, FieldInfo, MessageFile, RosLiteral, ServiceFile};
 
 fn derive_attrs() -> Vec<syn::Attribute> {
-    // TODO we should look into using $crate here...
-    // The way we're currently doing it leaks a dependency on these crates to users...
-    // However using $crate breaks the generated code in non-macro usage
-    // Pass a flag in "if_macro"?
     vec![
-        parse_quote! { #[derive(::serde::Deserialize)] },
-        parse_quote! { #[derive(::serde::Serialize)] },
-        parse_quote! { #[derive(::smart_default::SmartDefault)] },
+        parse_quote! { #[derive(::roslibrust_codegen::Deserialize)] },
+        parse_quote! { #[derive(::roslibrust_codegen::Serialize)] },
+        parse_quote! { #[derive(::roslibrust_codegen::SmartDefault)] },
         parse_quote! { #[derive(Debug)] },
         parse_quote! { #[derive(Clone)] },
         parse_quote! { #[derive(PartialEq)] },
+        parse_quote! { #[serde(crate = "::roslibrust_codegen::serde")] },
     ]
 }
 
@@ -179,7 +176,7 @@ fn generate_field_definition(
     const MAX_FIXED_ARRAY_LEN: usize = 32;
     let serde_line = match field.field_type.array_info {
         Some(Some(fixed_array_len)) if fixed_array_len > MAX_FIXED_ARRAY_LEN => {
-            quote! { #[serde(with = "::serde_big_array::BigArray")] }
+            quote! { #[serde(with = "::roslibrust_codegen::BigArray")] }
         }
         _ => quote! {},
     };

roslibrust_codegen/src/lib.rs

@@ -1,8 +1,6 @@
 use log::*;
 use proc_macro2::TokenStream;
 use quote::quote;
-use serde::de::DeserializeOwned;
-use serde::Serialize;
 use simple_error::{bail, SimpleError as Error};
 use std::collections::{BTreeMap, VecDeque};
 use std::fmt::{Debug, Display};
@@ -19,6 +17,15 @@ use utils::RosVersion;
 pub mod integral_types;
 pub use integral_types::*;
 
+// These pub use statements are here to be able to export the dependencies of the generated code
+// so that crates using this crate don't need to add these dependencies themselves.
+// Our generated code should find these exports.
+// Modeled from: https://users.rust-lang.org/t/proc-macros-using-third-party-crate/42465/4
+pub use serde::{de::DeserializeOwned, Deserialize, Serialize};
+pub use ::serde;
+pub use smart_default::SmartDefault;
+pub use serde_big_array::BigArray;
+
 /// Fundamental traits for message types this crate works with
 /// This trait will be satisfied for any types generated with this crate's message_gen functionality
 pub trait RosMessageType:

roslibrust_test/Cargo.toml

@@ -8,11 +8,6 @@ env_logger = "0.10"
 roslibrust = { path = "../roslibrust" }
 roslibrust_codegen = { path = "../roslibrust_codegen" }
 lazy_static = "1.4"
-# None of these three dependencies should have to be in here, they are leaking from generated code...
-serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
-smart-default = "0.6"
-serde-big-array = "0.5"
 
 [dev-dependencies]
 diffy = "0.3.0"