perf: avoid unnecessary api calls (#161)

* perf: avoid unnecessary api calls

* [autofix.ci] apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

tests/download-url.spec.ts

@@ -0,0 +1,161 @@
+import { afterEach, beforeEach, describe, expect, it, spyOn } from "bun:test";
+import { getDownloadUrl } from "../src/download-url";
+import * as utils from "../src/utils";
+
+const MOCK_TAGS = [
+  { ref: "refs/tags/bun-v0.5.0" },
+  { ref: "refs/tags/bun-v1.0.0" },
+  { ref: "refs/tags/bun-v1.0.1" },
+  { ref: "refs/tags/bun-v1.1.0" },
+  { ref: "refs/tags/canary" },
+];
+
+describe("getDownloadUrl", () => {
+  let requestSpy: ReturnType<typeof spyOn>;
+
+  beforeEach(() => {
+    requestSpy = spyOn(utils, "request").mockResolvedValue({
+      json: async () => MOCK_TAGS,
+    } as Response);
+  });
+
+  afterEach(() => {
+    requestSpy.mockRestore();
+  });
+
+  describe("Custom URL", () => {
+    it("should return customUrl if provided", async () => {
+      const url = await getDownloadUrl({
+        customUrl: "https://example.com/bun.zip",
+      });
+      expect(url).toBe("https://example.com/bun.zip");
+      expect(requestSpy).toHaveBeenCalledTimes(0);
+    });
+  });
+
+  describe("Optimization (No API Call)", () => {
+    it("should construct URL directly for specific version 1.0.0", async () => {
+      const url = await getDownloadUrl({
+        version: "1.0.0",
+        os: "linux",
+        arch: "x64",
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v1.0.0/bun-linux-x64.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(0);
+    });
+
+    it("should construct URL directly for specific version 0.5.0", async () => {
+      const url = await getDownloadUrl({
+        version: "0.5.0",
+        os: "darwin",
+        arch: "aarch64",
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v0.5.0/bun-darwin-aarch64.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(0);
+    });
+
+    it("should handle avx2=false (baseline) without API call", async () => {
+      const url = await getDownloadUrl({
+        version: "1.1.0",
+        os: "linux",
+        arch: "x64",
+        avx2: false,
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v1.1.0/bun-linux-x64-baseline.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(0);
+    });
+
+    it("should handle profile=true without API call", async () => {
+      const url = await getDownloadUrl({
+        version: "1.1.0",
+        os: "linux",
+        arch: "x64",
+        profile: true,
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v1.1.0/bun-linux-x64-profile.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(0);
+    });
+  });
+
+  describe("API Lookup (Dynamic Versions)", () => {
+    it("should call API and resolve 'latest' to the newest version", async () => {
+      const url = await getDownloadUrl({
+        version: "latest",
+        os: "linux",
+        arch: "x64",
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v1.1.0/bun-linux-x64.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(1);
+    });
+
+    it("should call API and resolve semver range '^1.0.0'", async () => {
+      const url = await getDownloadUrl({
+        version: "^1.0.0",
+        os: "linux",
+        arch: "x64",
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/bun-v1.1.0/bun-linux-x64.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(1);
+    });
+
+    it("should call API and resolve 'canary'", async () => {
+      const url = await getDownloadUrl({
+        version: "canary",
+        os: "linux",
+        arch: "x64",
+      });
+
+      expect(url).toBe(
+        "https://github.com/oven-sh/bun/releases/download/canary/bun-linux-x64.zip",
+      );
+      expect(requestSpy).toHaveBeenCalledTimes(1);
+    });
+
+    it("should throw error if semver range matches nothing", async () => {
+      expect(
+        getDownloadUrl({
+          version: "^2.0.0",
+          os: "linux",
+          arch: "x64",
+        }),
+      ).rejects.toThrow("No Bun release found matching version '^2.0.0'");
+      expect(requestSpy).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe("Token Handling", () => {
+    it("should pass token to API request when resolving dynamic versions", async () => {
+      await getDownloadUrl({
+        version: "latest",
+        token: "my-secret-token",
+        os: "linux",
+        arch: "x64",
+      });
+
+      expect(requestSpy).toHaveBeenCalledWith(
+        expect.stringContaining("api.github.com"),
+        expect.objectContaining({
+          headers: { Authorization: "Bearer my-secret-token" },
+        }),
+      );
+    });
+  });
+});