feat: expose DownloadBinary function

Author: alnr

testserver/binaries.go

@@ -118,13 +118,13 @@ func GetDownloadResponse(desiredVersion string, nonStable bool) (*http.Response,
 	return response, desiredVersion, nil
 }
 
-// downloadBinary saves the latest version of CRDB into a local binary file,
+// DownloadBinary saves the latest version of CRDB into a local binary file,
 // and returns the path for this local binary.
 // To download a specific cockroach version, specify desiredVersion. Otherwise,
 // the latest stable or non-stable version will be chosen.
 // To download the latest STABLE version of CRDB, set `nonStable` to false.
 // To download the bleeding edge version of CRDB, set `nonStable` to true.
-func downloadBinary(tc *TestConfig, desiredVersion string, nonStable bool) (string, error) {
+func DownloadBinary(tc *TestConfig, desiredVersion string, nonStable bool) (string, error) {
 	response, desiredVersion, err := GetDownloadResponse(desiredVersion, nonStable)
 	if err != nil {
 		return "", err

testserver/testserver.go

@@ -442,7 +442,7 @@ func NewTestServer(opts ...TestServerOpt) (TestServer, error) {
 			serverArgs.cockroachBinary = cockroachBinary
 		}
 	} else {
-		serverArgs.cockroachBinary, err = downloadBinary(&serverArgs.testConfig, serverArgs.customVersion, serverArgs.nonStableDB)
+		serverArgs.cockroachBinary, err = DownloadBinary(&serverArgs.testConfig, serverArgs.customVersion, serverArgs.nonStableDB)
 		if err != nil {
 			if errors.Is(err, errStoppedInMiddle) {
 				// If the testserver is intentionally killed in the middle of downloading,