fix(setup): preserve Linux Hopper HTTP failure status (#7183)

Preserve observed failed-response HTTP status through Linux Hopper setup diagnostics without changing download rejection, retry, or installation policy. Independently validated on latest main through red/green regressions, actual TLS sockets, focused checks and CI. Closes #7182.

tests/process-global/hopperDownloadHttpFailure.test.ts

@@ -0,0 +1,132 @@
+import { afterEach, expect, it, vi } from "vitest";
+
+import { createDoctorHostFixture } from "../../src/application/Doctor.fixture.js";
+import { downloadHopperPackage } from "../../src/application/HopperDownload.js";
+import {
+  systemLinuxHopperInstallHost,
+  type LinuxHopperInstallHost,
+} from "../../src/application/LinuxHopper.js";
+import { systemSetupHost } from "../../src/application/SetupHost.js";
+import { ok } from "../../src/domain/result.js";
+
+vi.mock("../../src/application/LinuxHopper.js", async (importOriginal) => ({
+  ...(await importOriginal<
+    typeof import("../../src/application/LinuxHopper.js")
+  >()),
+  systemLinuxHopperInstallHost: vi.fn(),
+}));
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+  vi.restoreAllMocks();
+});
+
+const url =
+  "https://www.hopperapp.com/downloader/public/Hopper-fixture-Linux-demo.deb";
+const generic =
+  "REA could not download or unpack the official Hopper package. Check network and filesystem access, then retry setup.";
+
+const installHost = (): LinuxHopperInstallHost => {
+  const unexpected = vi.fn((): never => {
+    throw new Error("Unexpected installation effect");
+  });
+  return {
+    distribution: async () => ({
+      id: "ubuntu",
+      versionId: "24.04",
+      packageFamily: "deb",
+      hopperSetupSupported: true,
+    }),
+    release: async () =>
+      ok({
+        version: "fixture",
+        filename: url,
+        file_length: "1",
+        file_hash: "0".repeat(40),
+        main_exe_hash: "0".repeat(64),
+        signature: "AA==",
+        public: "1",
+        beta: "0",
+      }),
+    download: downloadHopperPackage,
+    createTemporaryDirectory: unexpected,
+    writeArchive: unexpected,
+    installPackage: unexpected,
+    verifyArchive: unexpected,
+    retainVerifiedArchive: unexpected,
+    launcherStatus: unexpected,
+    cleanup: unexpected,
+  };
+};
+
+const setupFailure = async () => {
+  vi.mocked(systemLinuxHopperInstallHost).mockReturnValue(installHost());
+  const host = systemSetupHost(
+    createDoctorHostFixture({ platform: "linux" }),
+    {},
+  );
+  try {
+    return await host.installHopper(false);
+  } finally {
+    expect(await host.close?.()).toBeUndefined();
+  }
+};
+
+it.each([404, 503])(
+  "preserves HTTP %i from download through Linux setup diagnostics",
+  async (status) => {
+    const cancel = vi.fn();
+    const fetch = vi
+      .fn<typeof globalThis.fetch>()
+      .mockImplementation(
+        async () => new Response(new ReadableStream({ cancel }), { status }),
+      );
+    vi.stubGlobal("fetch", fetch);
+    expect(await downloadHopperPackage(url)).toEqual({
+      ok: false,
+      bytes: new Uint8Array(),
+      httpStatus: status,
+    });
+    expect(await setupFailure()).toEqual({
+      status: "failed",
+      code: "download_failed",
+      remediation: `download: Package download returned HTTP ${status}. ${generic}`,
+    });
+    expect(fetch).toHaveBeenCalledTimes(2);
+    expect(cancel).toHaveBeenCalledTimes(2);
+  },
+);
+
+it.each([undefined, null, 0, 200, 600, 503.5, "503", Number.NaN])(
+  "keeps generic diagnostics when the failed response status is %s",
+  async (status) => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn<typeof globalThis.fetch>().mockImplementation(async () => {
+        const response = new Response(null, { status: 503 });
+        Object.defineProperty(response, "status", { value: status });
+        return response;
+      }),
+    );
+    expect(await downloadHopperPackage(url)).toEqual({
+      ok: false,
+      bytes: new Uint8Array(),
+    });
+    expect(await setupFailure()).toEqual({
+      status: "failed",
+      code: "download_failed",
+      remediation: generic,
+    });
+  },
+);
+
+it("keeps a successful download unchanged", async () => {
+  vi.stubGlobal(
+    "fetch",
+    vi.fn<typeof globalThis.fetch>().mockResolvedValue(new Response("package")),
+  );
+  expect(await downloadHopperPackage(url)).toEqual({
+    ok: true,
+    bytes: Buffer.from("package"),
+  });
+});