feat(build): use prettyplease to format output (#890) (#904)

tonic-build/src/lib.rs

@@ -1,12 +1,6 @@
 //! `tonic-build` compiles `proto` files via `prost` and generates service stubs
 //! and proto definitiones for use with `tonic`.
 //!
-//! # Features
-//!
-//! - `rustfmt`: This feature enables the use of `rustfmt` to format the output code
-//! this makes the code readable and the error messages nice. This requires that `rustfmt`
-//! is installed. This is enabled by default.
-//!
 //! # Required dependencies
 //!
 //! ```toml
@@ -85,13 +79,6 @@ mod prost;
 #[cfg_attr(docsrs, doc(cfg(feature = "prost")))]
 pub use prost::{compile_protos, configure, Builder};
 
-#[cfg(feature = "rustfmt")]
-#[cfg_attr(docsrs, doc(cfg(feature = "rustfmt")))]
-use std::io::{self, Write};
-#[cfg(feature = "rustfmt")]
-#[cfg_attr(docsrs, doc(cfg(feature = "rustfmt")))]
-use std::process::{exit, Command};
-
 /// Service code generation for client
 pub mod client;
 /// Service code generation for Server
@@ -217,42 +204,6 @@ fn generate_attributes<'a>(
         .collect::<Vec<_>>()
 }
 
-/// Format files under the out_dir with rustfmt
-#[cfg(feature = "rustfmt")]
-#[cfg_attr(docsrs, doc(cfg(feature = "rustfmt")))]
-pub fn fmt(out_dir: &str) {
-    let dir = std::fs::read_dir(out_dir).unwrap();
-
-    for entry in dir {
-        let file = entry.unwrap().file_name().into_string().unwrap();
-        if !file.ends_with(".rs") {
-            continue;
-        }
-        let result =
-            Command::new(std::env::var("RUSTFMT").unwrap_or_else(|_| "rustfmt".to_owned()))
-                .arg("--emit")
-                .arg("files")
-                .arg("--edition")
-                .arg("2018")
-                .arg(format!("{}/{}", out_dir, file))
-                .output();
-
-        match result {
-            Err(e) => {
-                eprintln!("error running rustfmt: {:?}", e);
-                exit(1)
-            }
-            Ok(output) => {
-                if !output.status.success() {
-                    io::stdout().write_all(&output.stdout).unwrap();
-                    io::stderr().write_all(&output.stderr).unwrap();
-                    exit(output.status.code().unwrap_or(1))
-                }
-            }
-        }
-    }
-}
-
 // Generate a singular line of a doc comment
 fn generate_doc_comment<S: AsRef<str>>(comment: S) -> TokenStream {
     let mut doc_stream = TokenStream::new();

tonic-build/src/prost.rs

@@ -22,8 +22,6 @@ pub fn configure() -> Builder {
         client_attributes: Attributes::default(),
         proto_path: "super".to_string(),
         compile_well_known_types: false,
-        #[cfg(feature = "rustfmt")]
-        format: true,
         emit_package: true,
         protoc_args: Vec::new(),
         include_file: None,
@@ -184,7 +182,8 @@ impl prost_build::ServiceGenerator for ServiceGenerator {
                 #clients
             };
 
-            let code = format!("{}", client_service);
+            let ast: syn::File = syn::parse2(client_service).expect("not a valid tokenstream");
+            let code = prettyplease::unparse(&ast);
             buf.push_str(&code);
 
             self.clients = TokenStream::default();
@@ -197,7 +196,8 @@ impl prost_build::ServiceGenerator for ServiceGenerator {
                 #servers
             };
 
-            let code = format!("{}", server_service);
+            let ast: syn::File = syn::parse2(server_service).expect("not a valid tokenstream");
+            let code = prettyplease::unparse(&ast);
             buf.push_str(&code);
 
             self.servers = TokenStream::default();
@@ -223,8 +223,6 @@ pub struct Builder {
     pub(crate) include_file: Option<PathBuf>,
 
     out_dir: Option<PathBuf>,
-    #[cfg(feature = "rustfmt")]
-    format: bool,
 }
 
 impl Builder {
@@ -247,13 +245,6 @@ impl Builder {
         self
     }
 
-    /// Enable the output to be formated by rustfmt.
-    #[cfg(feature = "rustfmt")]
-    pub fn format(mut self, run: bool) -> Self {
-        self.format = run;
-        self
-    }
-
     /// Set the output directory to generate code to.
     ///
     /// Defaults to the `OUT_DIR` environment variable.
@@ -397,9 +388,6 @@ impl Builder {
             PathBuf::from(std::env::var("OUT_DIR").unwrap())
         };
 
-        #[cfg(feature = "rustfmt")]
-        let format = self.format;
-
         config.out_dir(out_dir.clone());
         if let Some(path) = self.file_descriptor_set_path.as_ref() {
             config.file_descriptor_set_path(path);
@@ -428,13 +416,6 @@ impl Builder {
 
         config.compile_protos(protos, includes)?;
 
-        #[cfg(feature = "rustfmt")]
-        {
-            if format {
-                super::fmt(out_dir.to_str().expect("Expected utf8 out_dir"));
-            }
-        }
-
         Ok(())
     }
 }