fix: classify duplicate vendor conflicts from parsed body (#149)

Co-authored-by: Codex Review Integration <codex-review@local.invalid>

src/domain/vendors/api/vendor-company-roster-api.ts

@@ -19,6 +19,7 @@ const OPEN_WORK_ORDER_MESSAGE =
 
 async function readConflictBody(error: unknown): Promise<unknown> {
   if (!isHTTPError(error)) return undefined;
+  if (error.data !== undefined && error.data !== null) return error.data;
   try {
     return await error.response.json();
   } catch {

src/test/domain/vendors/api/vendor-company-roster-api.test.ts

@@ -137,6 +137,41 @@ describe("vendorCompanyRosterApi", () => {
     );
   });
 
+  it("classifies a duplicate 409 from parsed error.data when the response body is consumed", async () => {
+    const conflictError = new Error("HTTPError") as Error & {
+      __kyHTTPError: true;
+      data: unknown;
+      response: { status: number; json: () => Promise<unknown>; text: () => Promise<string> };
+    };
+    conflictError.__kyHTTPError = true;
+    conflictError.data = {
+      code: "duplicate_vendor_company_name",
+      message: "Another vendor company already uses that name.",
+    };
+    const consumedBody = () => {
+      const rejection = Promise.reject(new TypeError("Body has already been consumed"));
+      rejection.catch(() => {});
+      return rejection;
+    };
+    conflictError.response = {
+      status: 409,
+      json: () => consumedBody(),
+      text: () => consumedBody(),
+    };
+
+    apiPost.mockRejectedValueOnce(conflictError);
+
+    await expect(vendorCompanyRosterApi.create({ name: "Solo Co" })).rejects.toSatisfy(
+      (error: unknown) => {
+        if (!isVendorRosterConflictError(error)) return false;
+        return (
+          error.conflict.kind === "duplicate" &&
+          error.conflict.message === "Another vendor company already uses that name."
+        );
+      },
+    );
+  });
+
   it("rethrows non-conflict errors untouched", async () => {
     const generic = new Error("boom");
     apiPost.mockRejectedValueOnce(generic);