Use astral-sh/versions as primary version provider (#802)

Closes: #777
Closes: #325

__tests__/download/version-manifest.test.ts

@@ -0,0 +1,136 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+
+const mockWarning = jest.fn();
+
+jest.mock("@actions/core", () => ({
+  debug: jest.fn(),
+  info: jest.fn(),
+  warning: mockWarning,
+}));
+
+// biome-ignore lint/suspicious/noExplicitAny: Mock requires flexible typing in tests.
+const mockFetch = jest.fn<any>();
+jest.mock("../../src/utils/fetch", () => ({
+  fetch: mockFetch,
+}));
+
+import {
+  clearManifestCache,
+  getAllVersions,
+  getLatestKnownVersion,
+  getManifestArtifact,
+} from "../../src/download/version-manifest";
+
+const legacyManifestResponse = JSON.stringify([
+  {
+    arch: "x86_64",
+    artifactName: "uv-x86_64-unknown-linux-gnu.tar.gz",
+    downloadUrl:
+      "https://example.com/releases/download/0.7.12-alpha.1/uv-x86_64-unknown-linux-gnu.tar.gz",
+    platform: "unknown-linux-gnu",
+    version: "0.7.12-alpha.1",
+  },
+  {
+    arch: "x86_64",
+    artifactName: "uv-x86_64-unknown-linux-gnu.tar.gz",
+    downloadUrl:
+      "https://example.com/releases/download/0.7.13/uv-x86_64-unknown-linux-gnu.tar.gz",
+    platform: "unknown-linux-gnu",
+    version: "0.7.13",
+  },
+]);
+
+const ndjsonManifestResponse = `{"version":"0.10.0","artifacts":[{"platform":"x86_64-unknown-linux-gnu","variant":"default","url":"https://example.com/releases/download/0.10.0/uv-x86_64-unknown-linux-gnu.tar.gz","archive_format":"tar.gz","sha256":"checksum-100"}]}
+{"version":"0.9.30","artifacts":[{"platform":"x86_64-unknown-linux-gnu","variant":"default","url":"https://example.com/releases/download/0.9.30/uv-x86_64-unknown-linux-gnu.tar.gz","archive_format":"tar.gz","sha256":"checksum-0930"}]}`;
+
+const multiVariantManifestResponse = `{"version":"0.10.0","artifacts":[{"platform":"x86_64-unknown-linux-gnu","variant":"managed-python","url":"https://example.com/releases/download/0.10.0/uv-x86_64-unknown-linux-gnu-managed-python.tar.gz","archive_format":"tar.gz","sha256":"checksum-managed"},{"platform":"x86_64-unknown-linux-gnu","variant":"default","url":"https://example.com/releases/download/0.10.0/uv-x86_64-unknown-linux-gnu-default.zip","archive_format":"zip","sha256":"checksum-default"}]}`;
+
+function createMockResponse(
+  ok: boolean,
+  status: number,
+  statusText: string,
+  data: string,
+) {
+  return {
+    ok,
+    status,
+    statusText,
+    text: async () => data,
+  };
+}
+
+describe("version-manifest", () => {
+  beforeEach(() => {
+    clearManifestCache();
+    mockFetch.mockReset();
+    mockWarning.mockReset();
+  });
+
+  it("supports the legacy JSON manifest format", async () => {
+    mockFetch.mockResolvedValue(
+      createMockResponse(true, 200, "OK", legacyManifestResponse),
+    );
+
+    const latest = await getLatestKnownVersion(
+      "https://example.com/legacy.json",
+    );
+    const artifact = await getManifestArtifact(
+      "https://example.com/legacy.json",
+      "0.7.13",
+      "x86_64",
+      "unknown-linux-gnu",
+    );
+
+    expect(latest).toBe("0.7.13");
+    expect(artifact).toEqual({
+      archiveFormat: undefined,
+      checksum: undefined,
+      downloadUrl:
+        "https://example.com/releases/download/0.7.13/uv-x86_64-unknown-linux-gnu.tar.gz",
+    });
+    expect(mockWarning).toHaveBeenCalledTimes(1);
+  });
+
+  it("supports NDJSON manifests", async () => {
+    mockFetch.mockResolvedValue(
+      createMockResponse(true, 200, "OK", ndjsonManifestResponse),
+    );
+
+    const versions = await getAllVersions("https://example.com/custom.ndjson");
+    const artifact = await getManifestArtifact(
+      "https://example.com/custom.ndjson",
+      "0.10.0",
+      "x86_64",
+      "unknown-linux-gnu",
+    );
+
+    expect(versions).toEqual(["0.10.0", "0.9.30"]);
+    expect(artifact).toEqual({
+      archiveFormat: "tar.gz",
+      checksum: "checksum-100",
+      downloadUrl:
+        "https://example.com/releases/download/0.10.0/uv-x86_64-unknown-linux-gnu.tar.gz",
+    });
+    expect(mockWarning).not.toHaveBeenCalled();
+  });
+
+  it("prefers the default variant when a manifest contains multiple variants", async () => {
+    mockFetch.mockResolvedValue(
+      createMockResponse(true, 200, "OK", multiVariantManifestResponse),
+    );
+
+    const artifact = await getManifestArtifact(
+      "https://example.com/multi-variant.ndjson",
+      "0.10.0",
+      "x86_64",
+      "unknown-linux-gnu",
+    );
+
+    expect(artifact).toEqual({
+      archiveFormat: "zip",
+      checksum: "checksum-default",
+      downloadUrl:
+        "https://example.com/releases/download/0.10.0/uv-x86_64-unknown-linux-gnu-default.zip",
+    });
+  });
+});