refactor: 프론트엔드 리펙토링

src/features/reference-feature/contracts/reference-mapper.ts

@@ -8,6 +8,7 @@ import {
   type InstalledBoundaryMapper,
   type MappingResult,
 } from "../../../contracts/boundary-mapper.ts";
+import type { ReferenceResourceDto } from "./reference-schemas.ts";
 
 export type ReferenceResourceView = Readonly<{
   resourceId: string;
@@ -16,22 +17,19 @@ export type ReferenceResourceView = Readonly<{
   optimistic?: boolean;
 }>;
 
+/**
+ * Operation-specific mapper. The HTTP contract has already validated the wire
+ * shape, so this mapper owns only wire -> domain construction.
+ */
 export function mapReferenceResourcePayload(
-  value: unknown,
+  dto: ReferenceResourceDto,
 ): MappingResult<ReferenceResource> {
-  if (!value || typeof value !== "object") {
-    return mappingFailure("MAPPING_INVARIANT_REJECTED");
-  }
-  const dto = value as Record<string, unknown>;
-  if (typeof dto.id !== "string" || typeof dto.name !== "string") {
-    return mappingFailure("MAPPING_INVARIANT_REJECTED");
-  }
   try {
     return mappingSuccess(
       createReferenceResource({
         id: dto.id,
         displayName: dto.name,
-        createdAt: typeof dto.createdAt === "string" ? dto.createdAt : null,
+        createdAt: dto.createdAt ?? null,
       }),
     );
   } catch {
@@ -40,14 +38,8 @@ export function mapReferenceResourcePayload(
 }
 
 export function mapReferenceResourceListPayload(
-  payload: unknown,
+  payload: readonly ReferenceResourceDto[],
 ): MappingResult<readonly ReferenceResource[]> {
-  if (!Array.isArray(payload)) {
-    return mappingFailure("MAPPING_INVARIANT_REJECTED");
-  }
-  if (payload.length > 100) {
-    return mappingFailure("OUTPUT_LIMIT_EXCEEDED");
-  }
   const output: ReferenceResource[] = [];
   for (const item of payload) {
     const mapped = mapReferenceResourcePayload(item);
@@ -57,22 +49,58 @@ export function mapReferenceResourceListPayload(
   return mappingSuccess(Object.freeze(output));
 }
 
+function isReferenceResourceDto(value: unknown): value is ReferenceResourceDto {
+  if (!value || typeof value !== "object" || Array.isArray(value)) return false;
+  const dto = value as Record<string, unknown>;
+  return (
+    typeof dto.id === "string" &&
+    typeof dto.name === "string" &&
+    (dto.createdAt === undefined || typeof dto.createdAt === "string")
+  );
+}
+
+function mapUnknownReferenceResourcePayload(
+  value: unknown,
+): MappingResult<ReferenceResource> {
+  return isReferenceResourceDto(value)
+    ? mapReferenceResourcePayload(value)
+    : mappingFailure("MAPPING_INVARIANT_REJECTED");
+}
+
+function mapUnknownReferenceResourceListPayload(
+  value: unknown,
+): MappingResult<readonly ReferenceResource[]> {
+  if (
+    !Array.isArray(value) ||
+    value.length > 100 ||
+    !value.every(isReferenceResourceDto)
+  ) {
+    return mappingFailure(
+      Array.isArray(value) && value.length > 100
+        ? "OUTPUT_LIMIT_EXCEEDED"
+        : "MAPPING_INVARIANT_REJECTED",
+    );
+  }
+  return mapReferenceResourceListPayload(value);
+}
+
 /**
- * Registry-facing compatibility projection. Feature adapters should prefer the
- * operation-specific mapper functions above so their result type is exact.
+ * Registry-facing compatibility projection. The registry is intentionally
+ * untyped, so its adapter performs the defensive shape check. Feature HTTP
+ * bindings use the typed operation-specific mappers above.
  */
 export function mapReferenceOperation(
   operationId: string,
   payload: unknown,
 ): MappingResult<ReferenceResource | readonly ReferenceResource[]> {
   if (operationId === "LIST_REFERENCE_RESOURCES") {
-    return mapReferenceResourceListPayload(payload);
+    return mapUnknownReferenceResourceListPayload(payload);
   }
   if (
     operationId === "CREATE_REFERENCE_RESOURCE" ||
     operationId === "GET_REFERENCE_RESOURCE"
   ) {
-    return mapReferenceResourcePayload(payload);
+    return mapUnknownReferenceResourcePayload(payload);
   }
   return mappingFailure("MAPPING_INVARIANT_REJECTED");
 }
@@ -85,7 +113,7 @@ export const REFERENCE_BOUNDARY_MAPPERS = Object.freeze({
     outputContractId: "ReferenceResourceList",
     owner: "feature-frontend-reference-feature-vertical-slice",
     maxOutputItems: 100,
-    map: mapReferenceResourceListPayload,
+    map: mapUnknownReferenceResourceListPayload,
   }),
   ReferenceResourceMapper: Object.freeze({
     mapperId: "ReferenceResourceMapper",
@@ -94,7 +122,7 @@ export const REFERENCE_BOUNDARY_MAPPERS = Object.freeze({
     outputContractId: "ReferenceResource",
     owner: "feature-frontend-reference-feature-vertical-slice",
     maxOutputItems: 1,
-    map: mapReferenceResourcePayload,
+    map: mapUnknownReferenceResourcePayload,
   }),
 } satisfies Readonly<Record<string, InstalledBoundaryMapper>>);