Add native Windows 11 ARM64 support for Chrome, Chromium, and Edge

go.sum

@@ -17,8 +17,6 @@ github.com/sirupsen/logrus v1.9.4/go.mod h1:ftWc9WdOfJ0a92nsE2jF5u5ZwH8Bv2zdeOC4
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
-golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
 golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

lib/launcher/browser.go

@@ -22,7 +22,7 @@ import (
 )
 
 /*
-	Google's Chromium-for-Testing (CfT) project provides builds for macOS (Intel and ARM), Windows (x86 and x64), and Linux (x64):
+	Google's Chromium-for-Testing (CfT) project provides builds for macOS (Intel and ARM), Windows (x86, x64, and ARM64), and Linux (x64):
 	- https://googlechromelabs.github.io/chrome-for-testing/last-known-good-versions-with-downloads.json
 
 	Playwright offers Chromium builds for Linux on ARM:
@@ -150,8 +150,9 @@ func ResolveChromiumForTestingPlatform(os string, arch string) string {
 		}
 	case "windows":
 		switch arch {
-		case "amd64",
-			"arm64": // Windows ARM64 uses the x86_64 binary via emulation
+		case "arm64": // Windows 11 ARM64 has native Chrome-for-Testing builds
+			return "win-arm64"
+		case "amd64":
 			return "win64"
 		case "386":
 			return "win32"
@@ -226,20 +227,26 @@ func ResolveLatestDownloadURLWithCache(os string, arch string) (string, string,
 // resolveLatestDownloadURL fetches the latest Chromium download URL for the specified OS and architecture.
 // It returns an error if the platform is unsupported or if there are issues fetching or parsing the metadata.
 func resolveLatestDownloadURL(os string, arch string) (string, string, error) {
-	// Microsoft's Playwright does not support Windows ARM64 and falls back to emulation using Win64
-	if os == "windows" && arch == "arm64" {
-		arch = "amd64"
-	}
 	// First try Google Chromium-for-Testing for common platforms
 	if cftPlatform := ResolveChromiumForTestingPlatform(os, arch); cftPlatform != "" {
 		var latestJSON GoogleCFTLatestDownloadsMeta
 		if err := downloadAndParseJSON(ChromiumForTestingLatestDownloadsURL, &latestJSON); err != nil {
 			return "", "", err
 		}
 		stable := latestJSON.Channels.Stable
-		for _, download := range stable.Downloads.Chrome {
-			if download.Platform == cftPlatform {
-				return download.URL, stable.Revision, nil
+
+		// Prefer the native platform build, but on Windows ARM64 fall back to
+		// the x86_64 (win64) build via emulation when Chromium-for-Testing does
+		// not publish a native win-arm64 build for the stable channel.
+		candidatePlatforms := []string{cftPlatform}
+		if os == "windows" && arch == "arm64" {
+			candidatePlatforms = append(candidatePlatforms, "win64")
+		}
+		for _, platform := range candidatePlatforms {
+			for _, download := range stable.Downloads.Chrome {
+				if download.Platform == platform {
+					return download.URL, stable.Revision, nil
+				}
 			}
 		}
 	}

lib/launcher/launcher_test.go

@@ -246,6 +246,16 @@ func Test_ResolveDownloadURL(t *testing.T) {
 			},
 			wantMatch: regexp.MustCompile(`https://storage.googleapis.com/chrome-for-testing-public/[\d.]+/win64/chrome-win64.zip`),
 		},
+		{
+			name: "windows-arm64",
+			platform: srcPlatform{
+				os:   "windows",
+				arch: "arm64",
+			},
+			// Prefer the native win-arm64 build, but accept the win64 build
+			// when Chromium-for-Testing has not published a native build.
+			wantMatch: regexp.MustCompile(`https://storage.googleapis.com/chrome-for-testing-public/[\d.]+/win(-arm64|64)/chrome-win(-arm64|64).zip`),
+		},
 		{
 			name: "windows-x86",
 			platform: srcPlatform{
@@ -291,6 +301,30 @@ func Test_ResolveDownloadURL(t *testing.T) {
 	}
 }
 
+func Test_ResolveChromiumForTestingPlatform(t *testing.T) {
+	tests := []struct {
+		name string
+		os   string
+		arch string
+		want string
+	}{
+		{name: "windows-arm64", os: "windows", arch: "arm64", want: "win-arm64"},
+		{name: "windows-amd64", os: "windows", arch: "amd64", want: "win64"},
+		{name: "windows-386", os: "windows", arch: "386", want: "win32"},
+		{name: "darwin-arm64", os: "darwin", arch: "arm64", want: "mac-arm64"},
+		{name: "darwin-amd64", os: "darwin", arch: "amd64", want: "mac-x64"},
+		{name: "linux-amd64", os: "linux", arch: "amd64", want: "linux64"},
+		{name: "linux-arm64", os: "linux", arch: "arm64", want: ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := launcher.ResolveChromiumForTestingPlatform(tt.os, tt.arch); got != tt.want {
+				t.Errorf("ResolveChromiumForTestingPlatform(%q, %q) = %q, want %q", tt.os, tt.arch, got, tt.want)
+			}
+		})
+	}
+}
+
 func Test_ResolveDownloader(t *testing.T) {
 	b, err := launcher.NewBrowser()
 	if err != nil {