feat(build): Add CodeGenBuilder (#1154)

This commit adds a new `CodeGenBuilder` that replaces the
client/server generate fn with a builder stlye that allows
adding config items in an non-breaking way. This also deprecates
both of the client/server generate fn in favor of the builder ones.

tonic-build/Cargo.toml

@@ -12,7 +12,7 @@ license = "MIT"
 name = "tonic-build"
 readme = "README.md"
 repository = "https://github.com/hyperium/tonic"
-version = "0.8.2"
+version = "0.8.3"
 
 [dependencies]
 prettyplease = { version = "0.1" }

tonic-build/src/client.rs

@@ -9,6 +9,7 @@ use quote::{format_ident, quote};
 ///
 /// This takes some `Service` and will generate a `TokenStream` that contains
 /// a public module with the generated client.
+#[deprecated(since = "0.8.3", note = "Use the CodeGenBuilder::generate_client")]
 pub fn generate<T: Service>(
     service: &T,
     emit_package: bool,
@@ -16,6 +17,25 @@ pub fn generate<T: Service>(
     compile_well_known_types: bool,
     build_transport: bool,
     attributes: &Attributes,
+) -> TokenStream {
+    generate_internal(
+        service,
+        emit_package,
+        proto_path,
+        compile_well_known_types,
+        build_transport,
+        attributes,
+        &HashSet::default(),
+    )
+}
+
+pub(crate) fn generate_internal<T: Service>(
+    service: &T,
+    emit_package: bool,
+    proto_path: &str,
+    compile_well_known_types: bool,
+    build_transport: bool,
+    attributes: &Attributes,
     disable_comments: &HashSet<String>,
 ) -> TokenStream {
     let service_ident = quote::format_ident!("{}Client", service.name());

tonic-build/src/code_gen.rs

@@ -0,0 +1,102 @@
+use std::collections::HashSet;
+
+use proc_macro2::TokenStream;
+
+use crate::{Attributes, Service};
+
+/// Builder for the generic code generation of server and clients.
+#[derive(Debug)]
+pub struct CodeGen8uilder {
+    emit_package: bool,
+    compile_well_known_types: bool,
+    attributes: Attributes,
+    build_transport: bool,
+    disable_comments: HashSet<String>,
+}
+
+impl CodeGen8uilder {
+    /// Create a new code gen builder with default options.
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    /// Enable code generation to emit the package name.
+    pub fn emit_package(&mut self, enable: bool) -> &mut Self {
+        self.emit_package = enable;
+        self
+    }
+
+    /// Attributes that will be added to `mod` and `struct` items.
+    ///
+    /// Reference [`Attributes`] for more information.
+    pub fn attributes(&mut self, attributes: Attributes) -> &mut Self {
+        self.attributes = attributes;
+        self
+    }
+
+    /// Enable transport code to be generated, this requires `tonic`'s `transport`
+    /// feature.
+    ///
+    /// This allows codegen level control of generating the transport code and
+    /// is a work around when other crates in a workspace enable this feature.
+    pub fn build_transport(&mut self, build_transport: bool) -> &mut Self {
+        self.build_transport = build_transport;
+        self
+    }
+
+    /// Enable compiling well knonw types, this will force codegen to not
+    /// use the well known types from `prost-types`.
+    pub fn compile_well_known_types(&mut self, enable: bool) -> &mut Self {
+        self.compile_well_known_types = enable;
+        self
+    }
+
+    /// Disable comments based on a proto path.
+    pub fn disable_comments(&mut self, disable_comments: HashSet<String>) -> &mut Self {
+        self.disable_comments = disable_comments;
+        self
+    }
+
+    /// Generate client code based on `Service`.
+    ///
+    /// This takes some `Service` and will generate a `TokenStream` that contains
+    /// a public module with the generated client.
+    pub fn generate_client(&self, service: &impl Service, proto_path: &str) -> TokenStream {
+        crate::client::generate_internal(
+            service,
+            self.emit_package,
+            proto_path,
+            self.compile_well_known_types,
+            self.build_transport,
+            &self.attributes,
+            &self.disable_comments,
+        )
+    }
+
+    /// Generate server code based on `Service`.
+    ///
+    /// This takes some `Service` and will generate a `TokenStream` that contains
+    /// a public module with the generated client.
+    pub fn generate_server(&self, service: &impl Service, proto_path: &str) -> TokenStream {
+        crate::server::generate_internal(
+            service,
+            self.emit_package,
+            proto_path,
+            self.compile_well_known_types,
+            &self.attributes,
+            &self.disable_comments,
+        )
+    }
+}
+
+impl Default for CodeGen8uilder {
+    fn default() -> Self {
+        Self {
+            emit_package: true,
+            compile_well_known_types: false,
+            attributes: Attributes::default(),
+            build_transport: true,
+            disable_comments: HashSet::default(),
+        }
+    }
+}

tonic-build/src/lib.rs

@@ -94,6 +94,9 @@ pub mod client;
 /// Service code generation for Server
 pub mod server;
 
+mod code_gen;
+pub use code_gen::CodeGen8uilder;
+
 /// Service generation trait.
 ///
 /// This trait can be implemented and consumed

tonic-build/src/manual.rs

@@ -28,11 +28,11 @@
 //! }
 //! ```
 
-use super::{client, server, Attributes};
+use crate::code_gen::CodeGen8uilder;
+
 use proc_macro2::TokenStream;
 use quote::ToTokens;
 use std::{
-    collections::HashSet,
     fs,
     path::{Path, PathBuf},
 };
@@ -352,27 +352,21 @@ struct ServiceGenerator {
 impl ServiceGenerator {
     fn generate(&mut self, service: &Service) {
         if self.builder.build_server {
-            let server = server::generate(
-                service,
-                true,  // emit_package,
-                "",    // proto_path, -- not used
-                false, // compile_well_known_types -- not used
-                &Attributes::default(),
-                &HashSet::default(),
-            );
+            let server = CodeGen8uilder::new()
+                .emit_package(true)
+                .compile_well_known_types(false)
+                .generate_server(service, "");
+
             self.servers.extend(server);
         }
 
         if self.builder.build_client {
-            let client = client::generate(
-                service,
-                true,  // emit_package,
-                "",    // proto_path, -- not used
-                false, // compile_well_known_types, -- not used
-                self.builder.build_transport,
-                &Attributes::default(),
-                &HashSet::default(),
-            );
+            let client = CodeGen8uilder::new()
+                .emit_package(true)
+                .compile_well_known_types(false)
+                .build_transport(self.builder.build_transport)
+                .generate_client(service, "");
+
             self.clients.extend(client);
         }
     }

tonic-build/src/prost.rs

@@ -1,4 +1,6 @@
-use super::{client, server, Attributes};
+use crate::code_gen::CodeGen8uilder;
+
+use super::Attributes;
 use proc_macro2::TokenStream;
 use prost_build::{Config, Method, Service};
 use quote::ToTokens;
@@ -159,27 +161,25 @@ impl ServiceGenerator {
 impl prost_build::ServiceGenerator for ServiceGenerator {
     fn generate(&mut self, service: prost_build::Service, _buf: &mut String) {
         if self.builder.build_server {
-            let server = server::generate(
-                &service,
-                self.builder.emit_package,
-                &self.builder.proto_path,
-                self.builder.compile_well_known_types,
-                &self.builder.server_attributes,
-                &self.builder.disable_comments,
-            );
+            let server = CodeGen8uilder::new()
+                .emit_package(self.builder.emit_package)
+                .compile_well_known_types(self.builder.compile_well_known_types)
+                .attributes(self.builder.server_attributes.clone())
+                .disable_comments(self.builder.disable_comments.clone())
+                .generate_server(&service, &self.builder.proto_path);
+
             self.servers.extend(server);
         }
 
         if self.builder.build_client {
-            let client = client::generate(
-                &service,
-                self.builder.emit_package,
-                &self.builder.proto_path,
-                self.builder.compile_well_known_types,
-                self.builder.build_transport,
-                &self.builder.client_attributes,
-                &self.builder.disable_comments,
-            );
+            let client = CodeGen8uilder::new()
+                .emit_package(self.builder.emit_package)
+                .compile_well_known_types(self.builder.compile_well_known_types)
+                .attributes(self.builder.client_attributes.clone())
+                .disable_comments(self.builder.disable_comments.clone())
+                .build_transport(self.builder.build_transport)
+                .generate_client(&service, &self.builder.proto_path);
+
             self.clients.extend(client);
         }
     }

tonic-build/src/server.rs

@@ -10,12 +10,30 @@ use syn::{Ident, Lit, LitStr};
 ///
 /// This takes some `Service` and will generate a `TokenStream` that contains
 /// a public module containing the server service and handler trait.
+#[deprecated(since = "0.8.3", note = "Use CodeGenBuilder::generate_server")]
 pub fn generate<T: Service>(
     service: &T,
     emit_package: bool,
     proto_path: &str,
     compile_well_known_types: bool,
     attributes: &Attributes,
+) -> TokenStream {
+    generate_internal(
+        service,
+        emit_package,
+        proto_path,
+        compile_well_known_types,
+        attributes,
+        &HashSet::default(),
+    )
+}
+
+pub(crate) fn generate_internal<T: Service>(
+    service: &T,
+    emit_package: bool,
+    proto_path: &str,
+    compile_well_known_types: bool,
+    attributes: &Attributes,
     disable_comments: &HashSet<String>,
 ) -> TokenStream {
     let methods = generate_methods(service, proto_path, compile_well_known_types);