milestone 18: collapse duplicated infrastructure into shared listener core, crud list helper, resource shells, transport race, name and line helpers, ui modules

web/src/lib/InlineError.test.tsx

@@ -0,0 +1,24 @@
+import { fireEvent, render, screen } from "@testing-library/react";
+import { ApiError } from "@/lib/api";
+import InlineError from "./InlineError";
+
+test("no retry button without onRetry", () => {
+	render(<InlineError error={new ApiError(409, "already exists")} />);
+	expect(screen.getByRole("alert").textContent).toBe("already exists");
+	expect(screen.queryByRole("button", { name: "Retry" })).toBeNull();
+});
+
+test("onRetry renders a focusable retry button that calls back", () => {
+	const onRetry = vi.fn();
+	render(<InlineError error={new ApiError(500, "internal")} onRetry={onRetry} />);
+
+	const button = screen.getByRole("button", { name: "Retry" });
+	expect(button.className).toContain("focus-visible:outline-2");
+	fireEvent.click(button);
+	expect(onRetry).toHaveBeenCalledTimes(1);
+});
+
+test("a null error renders nothing even with onRetry", () => {
+	const { container } = render(<InlineError error={null} onRetry={() => undefined} />);
+	expect(container.innerHTML).toBe("");
+});