Simplify Plugin trait

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/ServerRustModule.kt

@@ -27,7 +27,6 @@ import software.amazon.smithy.rust.codegen.core.smithy.module
 import software.amazon.smithy.rust.codegen.core.smithy.traits.SyntheticInputTrait
 import software.amazon.smithy.rust.codegen.core.smithy.traits.SyntheticOutputTrait
 import software.amazon.smithy.rust.codegen.core.util.hasTrait
-import software.amazon.smithy.rust.codegen.core.util.toPascalCase
 import software.amazon.smithy.rust.codegen.core.util.toSnakeCase
 import software.amazon.smithy.rust.codegen.server.smithy.generators.DocHandlerGenerator
 import software.amazon.smithy.rust.codegen.server.smithy.generators.handlerImports
@@ -73,49 +72,22 @@ class ServerModuleDocProvider(private val codegenContext: ServerCodegenContext)
  val operations = index.getContainedOperations(codegenContext.serviceShape).toSortedSet(compareBy { it.id })
 
  val firstOperation = operations.first() ?: return@writable
- val firstOperationSymbol = codegenContext.symbolProvider.toSymbol(firstOperation)
- val firstOperationName = firstOperationSymbol.name.toPascalCase()
  val crateName = codegenContext.settings.moduleName.toSnakeCase()
 
  rustTemplate(
  """
  /// A collection of types representing each operation defined in the service closure.
  ///
- /// ## Constructing an [`Operation`](#{SmithyHttpServer}::operation::OperationShapeExt)
- ///
- /// To apply middleware to specific operations the [`Operation`](#{SmithyHttpServer}::operation::Operation)
- /// API must be used.
- ///
- /// Using the [`OperationShapeExt`](#{SmithyHttpServer}::operation::OperationShapeExt) trait
- /// implemented on each ZST we can construct an [`Operation`](#{SmithyHttpServer}::operation::Operation)
- /// with appropriate constraints given by Smithy.
- ///
- /// #### Example
- ///
- /// ```no_run
- /// use $crateName::operation_shape::$firstOperationName;
- /// use #{SmithyHttpServer}::operation::OperationShapeExt;
- ///
- #{HandlerImports:W}
- ///
- #{Handler:W}
- ///
- /// let operation = $firstOperationName::from_handler(handler)
- /// .layer(todo!("Provide a layer implementation"));
- /// ```
- ///
- /// ## Use as Marker Structs
- ///
- /// The [plugin system](#{SmithyHttpServer}::plugin) also makes use of these
+ /// The [plugin system](#{SmithyHttpServer}::plugin) makes use of these
  /// [zero-sized types](https://doc.rust-lang.org/nomicon/exotic-sizes.html##zero-sized-types-zsts) (ZSTs) to
- /// parameterize [`Plugin`](#{SmithyHttpServer}::plugin::Plugin) implementations. The traits, such as
- /// [`OperationShape`](#{SmithyHttpServer}::operation::OperationShape) can be used to provide
+ /// parameterize [`Plugin`](#{SmithyHttpServer}::plugin::Plugin) implementations. Their traits, such as
+ /// [`OperationShape`](#{SmithyHttpServer}::operation::OperationShape), can be used to provide
  /// operation specific information to the [`Layer`](#{Tower}::Layer) being applied.
  """.trimIndent(),
  "SmithyHttpServer" to
  ServerCargoDependency.smithyHttpServer(codegenContext.runtimeConfig).toType(),
  "Tower" to ServerCargoDependency.Tower.toType(),
- "Handler" to DocHandlerGenerator(codegenContext, firstOperation, "handler", commentToken = "///")::render,
+ "Handler" to DocHandlerGenerator(codegenContext, firstOperation, "handler", commentToken = "///").docSignature(),
  "HandlerImports" to handlerImports(crateName, operations, commentToken = "///"),
  )
  }

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/DocHandlerGenerator.kt

@@ -6,10 +6,8 @@
 package software.amazon.smithy.rust.codegen.server.smithy.generators
 
 import software.amazon.smithy.model.shapes.OperationShape
-import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
 import software.amazon.smithy.rust.codegen.core.rustlang.Writable
 import software.amazon.smithy.rust.codegen.core.rustlang.rust
-import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
 import software.amazon.smithy.rust.codegen.core.rustlang.writable
 import software.amazon.smithy.rust.codegen.core.smithy.CodegenContext
 import software.amazon.smithy.rust.codegen.core.util.inputShape
@@ -55,14 +53,21 @@ class DocHandlerGenerator(
  }
  }
 
- fun render(writer: RustWriter) {
- // This assumes that the `error` (if applicable) `input`, and `output` modules have been imported by the
- // caller and hence are in scope.
- writer.rustTemplate(
- """
- #{Handler:W}
- """,
- "Handler" to docSignature(),
- )
+ fun docFixedSignature(): Writable {
+ val outputT = if (operation.errors.isEmpty()) {
+ "Result<${OutputModule.name}::${outputSymbol.name}, std::convert::Infallible>"
+ } else {
+ "Result<${OutputModule.name}::${outputSymbol.name}, ${ErrorModule.name}::${errorSymbol.name}>"
+ }
+
+ return writable {
+ rust(
+ """
+ $commentToken async fn $handlerName(input: ${InputModule.name}::${inputSymbol.name}) -> $outputT {
+ $commentToken todo!()
+ $commentToken }
+ """.trimIndent(),
+ )
+ }
  }
 }

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ServerRootGenerator.kt

@@ -53,7 +53,7 @@ open class ServerRootGenerator(
  val hasErrors = operations.any { it.errors.isNotEmpty() }
  val handlers: Writable = operations
  .map { operation ->
- DocHandlerGenerator(codegenContext, operation, builderFieldNames[operation]!!, "//!")::render
+ DocHandlerGenerator(codegenContext, operation, builderFieldNames[operation]!!, "//!").docSignature()
  }
  .join("//!\n")
 
@@ -110,6 +110,7 @@ open class ServerRootGenerator(
  //! Plugins allow you to build middleware which is aware of the operation it is being applied to.
  //!
  //! ```rust
+ //! ## use #{SmithyHttpServer}::plugin::IdentityPlugin;
  //! ## use #{SmithyHttpServer}::plugin::IdentityPlugin as LoggingPlugin;
  //! ## use #{SmithyHttpServer}::plugin::IdentityPlugin as MetricsPlugin;
  //! ## use #{Hyper}::Body;
@@ -119,7 +120,7 @@ open class ServerRootGenerator(
  //! let plugins = PluginPipeline::new()
  //! .push(LoggingPlugin)
  //! .push(MetricsPlugin);
- //! let builder: $builderName<Body, _> = $serviceName::builder_with_plugins(plugins);
+ //! let builder: $builderName<Body, _, _> = $serviceName::builder_with_plugins(plugins, IdentityPlugin);
  //! ```
  //!
  //! Check out [`#{SmithyHttpServer}::plugin`] to learn more about plugins.

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/ServerRuntimeTypesReExportsGenerator.kt

@@ -28,7 +28,6 @@ class ServerRuntimeTypesReExportsGenerator(
  }
  pub mod operation {
  pub use #{SmithyHttpServer}::operation::OperationShape;
- pub use #{SmithyHttpServer}::operation::Operation;
  }
  pub mod plugin {
  pub use #{SmithyHttpServer}::plugin::Plugin;