Fix upgrade failing on macOS due to platform name mismatch (darwin→macos, win32→windows)

Co-authored-by: shouze <54712+shouze@users.noreply.github.com>

Author: Copilot

src/upgrade.test.ts

@@ -53,21 +53,21 @@ function makeAsset(name: string): ReleaseAsset {
 
 describe("selectAsset", () => {
   const assets: ReleaseAsset[] = [
-    makeAsset("github-code-search-darwin-arm64"),
-    makeAsset("github-code-search-darwin-x64"),
+    makeAsset("github-code-search-macos-arm64"),
+    makeAsset("github-code-search-macos-x64"),
     makeAsset("github-code-search-linux-x64"),
     makeAsset("github-code-search-linux-arm64"),
-    makeAsset("github-code-search-win32-x64.exe"),
+    makeAsset("github-code-search-windows-x64.exe"),
   ];
 
-  it("selects darwin-arm64 asset", () => {
+  it("selects macos-arm64 asset for darwin/arm64", () => {
     const asset = selectAsset(assets, "darwin", "arm64");
-    expect(asset?.name).toBe("github-code-search-darwin-arm64");
+    expect(asset?.name).toBe("github-code-search-macos-arm64");
   });
 
-  it("selects darwin-x64 asset", () => {
+  it("selects macos-x64 asset for darwin/x64", () => {
     const asset = selectAsset(assets, "darwin", "x64");
-    expect(asset?.name).toBe("github-code-search-darwin-x64");
+    expect(asset?.name).toBe("github-code-search-macos-x64");
   });
 
   it("selects linux-x64 asset", () => {
@@ -80,9 +80,9 @@ describe("selectAsset", () => {
     expect(asset?.name).toBe("github-code-search-linux-arm64");
   });
 
-  it("selects win32-x64 asset with .exe suffix", () => {
+  it("selects windows-x64 asset with .exe suffix for win32/x64", () => {
     const asset = selectAsset(assets, "win32", "x64");
-    expect(asset?.name).toBe("github-code-search-win32-x64.exe");
+    expect(asset?.name).toBe("github-code-search-windows-x64.exe");
   });
 
   it("returns null when no matching asset is found", () => {

src/upgrade.ts

@@ -38,16 +38,22 @@ export function isNewerVersion(current: string, latest: string): boolean {
 /**
  * Picks the release asset matching the current platform and architecture.
  * Expected asset naming convention:
- *   github-code-search-<platform>-<arch>          (e.g. darwin-arm64)
+ *   github-code-search-<platform>-<arch>          (e.g. macos-arm64)
  *   github-code-search-<platform>-<arch>.exe      (Windows)
+ *
+ * Node.js/Bun platform names are mapped to artifact names:
+ *   darwin → macos
+ *   win32  → windows
  */
 export function selectAsset(
   assets: ReleaseAsset[],
   platform: string,
   arch: string,
 ): ReleaseAsset | null {
-  const suffix = platform === "win32" ? ".exe" : "";
-  const name = `github-code-search-${platform}-${arch}${suffix}`;
+  const platformMap: Record<string, string> = { darwin: "macos", win32: "windows" };
+  const artifactPlatform = platformMap[platform] ?? platform;
+  const suffix = artifactPlatform === "windows" ? ".exe" : "";
+  const name = `github-code-search-${artifactPlatform}-${arch}${suffix}`;
   return assets.find((a) => a.name === name) ?? null;
 }