Fix code generation for json feature (#3367)

Author: Brent Gardner

datafusion/proto/build.rs

@@ -55,7 +55,7 @@ fn build() -> Result<(), String> {
     let mut file = std::fs::OpenOptions::new()
         .write(true)
         .create(true)
-        .open("src/generated/datafusion.rs")
+        .open("src/generated/datafusion_json.rs")
         .unwrap();
     file.write(proto.as_str().as_ref()).unwrap();
     file.write(json.as_str().as_ref()).unwrap();

datafusion/proto/src/generated/mod.rs

@@ -18,4 +18,10 @@
 // include the generated protobuf source as a submodule
 #[allow(clippy::all)]
 #[rustfmt::skip]
+#[cfg(not(feature = "json"))]
 pub mod datafusion;
+
+#[allow(clippy::all)]
+#[rustfmt::skip]
+#[cfg(feature = "json")]
+pub mod datafusion_json;

datafusion/proto/src/lib.rs

@@ -24,7 +24,11 @@ pub mod from_proto;
 pub mod generated;
 pub mod logical_plan;
 pub mod to_proto;
-use generated::datafusion as protobuf;
+
+#[cfg(not(feature = "json"))]
+pub use generated::datafusion as protobuf;
+#[cfg(feature = "json")]
+pub use generated::datafusion_json as protobuf;
 
 #[cfg(doctest)]
 doc_comment::doctest!("../README.md", readme_example_test);