Support struct functionality

packages/emitter-framework/src/csharp/components/index.ts

@@ -3,4 +3,5 @@ export * from "./enum/declaration.jsx";
 export * from "./json-converter/json-converter-resolver.jsx";
 export * from "./json-converter/json-converter.jsx";
 export * from "./property/property.jsx";
+export * from "./struct/struct.jsx";
 export * from "./type-expression.jsx";

packages/emitter-framework/src/csharp/components/struct/struct.tsx

@@ -0,0 +1,63 @@
+import { For, type Children } from "@alloy-js/core";
+import * as cs from "@alloy-js/csharp";
+import { isVoidType, type Model } from "@typespec/compiler";
+import { useTsp } from "../../../core/index.js";
+import { Property } from "../property/property.jsx";
+import { getDocComments } from "../utils/doc-comments.jsx";
+import { declarationRefkeys } from "../utils/refkey.js";
+
+export interface StructDeclarationProps extends Omit<cs.StructDeclarationProps, "name"> {
+  /** Set an alternative name for the Struct. Otherwise default to the type name. */
+  name?: string;
+  /** Type to use to create this Struct. */
+  type: Model;
+  /** If set the property will add the json serialization attributes(using System.Text.Json). */
+  jsonAttributes?: boolean;
+}
+
+interface StructPropertiesProps {
+  type: Model;
+  /** If set the property will add the json serialization attributes(using System.Text.Json). */
+  jsonAttributes?: boolean;
+}
+
+export function StructDeclaration(props: StructDeclarationProps): Children {
+  const { $ } = useTsp();
+
+  if (props.type.baseModel) {
+    // TODO: support flatten inheritance for structs automatically?
+    throw new Error(
+      `Inherit relationship found for type '${props.type.name}' which is not supported in struct.`,
+    );
+  }
+
+  const namePolicy = cs.useCSharpNamePolicy();
+  const structName = props.name ?? namePolicy.getName(props.type.name, "struct");
+
+  const refkeys = declarationRefkeys(props.refkey, props.type)[0]; // TODO: support multiple refkeys for declarations in alloy
+
+  return (
+    <>
+      <cs.StructDeclaration
+        {...props}
+        name={structName}
+        refkey={refkeys}
+        doc={getDocComments($, props.type)}
+      >
+        <StructProperties type={props.type} jsonAttributes={props.jsonAttributes} />
+      </cs.StructDeclaration>
+    </>
+  );
+}
+
+function StructProperties(props: StructPropertiesProps): Children {
+  // Ignore 'void' type properties which is not valid in csharp
+  const properties = Array.from(props.type.properties.entries()).filter(
+    ([_, p]) => !isVoidType(p.type),
+  );
+  return (
+    <For each={properties} doubleHardline>
+      {([name, property]) => <Property type={property} jsonAttributes={props.jsonAttributes} />}
+    </For>
+  );
+}