feat: contain DTO mapping at the HTTP boundary

tests/integration/http-client.test.js

@@ -46,7 +46,7 @@ describe("shared HTTP client", () => {
       client.execute("LIST_SAMPLE_RESOURCES", { routeId: "SAMPLE_RESOURCE_LIST" }),
     ).resolves.toMatchObject({
       ok: true,
-      value: [{ id: "resource-1" }],
+      value: [{ id: "resource-1", displayName: "Example" }],
       meta: { requestId: "request-1" },
     });
     expect(attempts).toBe(3);
@@ -99,4 +99,30 @@ describe("shared HTTP client", () => {
       error: { kind: "SCHEMA_MISMATCH" },
     });
   });
+
+  it("guards mapper exceptions as UNKNOWN_FAILURE", async () => {
+    server.use(
+      http.get("https://api.test/api/sample/resources", () =>
+        HttpResponse.json({
+          success: true,
+          data: [{ id: "resource-1", name: "Example" }],
+          meta: { requestId: "request-1", traceId: "trace-1" },
+        }),
+      ),
+    );
+    const client = createHttpClient({
+      baseUrl: "https://api.test",
+      clock,
+      mapPayload: () => {
+        throw new Error("raw mapper detail");
+      },
+    });
+
+    const result = await client.execute("LIST_SAMPLE_RESOURCES");
+    expect(result).toMatchObject({
+      ok: false,
+      error: { kind: "UNKNOWN_FAILURE" },
+    });
+    expect(JSON.stringify(result)).not.toContain("raw mapper detail");
+  });
 });

tests/unit/boundary-mapper.test.js

@@ -0,0 +1,52 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  mapOperationPayload,
+  mapResourceDto,
+} from "../../src/adapters/http/resource-mapper.js";
+import { toResourceViewModel } from "../../src/application/view-models/resource-view-model.js";
+
+describe("DTO to model to view-model mapping", () => {
+  it("contains raw DTO names at the HTTP boundary", () => {
+    const model = mapResourceDto({
+      id: "resource-1",
+      name: "Example",
+      createdAt: "2026-07-25T00:00:00.000Z",
+      backendOnly: "not propagated",
+    });
+
+    expect(model).toEqual({
+      id: "resource-1",
+      displayName: "Example",
+      createdAt: "2026-07-25T00:00:00.000Z",
+    });
+    expect(model).not.toHaveProperty("name");
+    expect(model).not.toHaveProperty("backendOnly");
+  });
+
+  it("maps operation payloads and rejects missing mappers", () => {
+    expect(
+      mapOperationPayload("LIST_SAMPLE_RESOURCES", [
+        { id: "resource-1", name: "Example" },
+      ]),
+    ).toEqual([
+      { id: "resource-1", displayName: "Example", createdAt: null },
+    ]);
+    expect(() => mapOperationPayload("UNKNOWN", {})).toThrow(
+      "No boundary mapper registered",
+    );
+  });
+
+  it("projects an application-owned render-ready shape", () => {
+    const model = mapResourceDto({
+      id: "resource-1",
+      name: "Example",
+      createdAt: null,
+    });
+    expect(toResourceViewModel(model)).toEqual({
+      resourceId: "resource-1",
+      title: "Example",
+      createdAtLabel: null,
+    });
+  });
+});