Verify supported Yarn version

artifactory/utils/yarn/configget.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 )
 
-// This method runs "yarn config set" command and sets the yarn configuration.
+// This method runs "yarn config get" command and sets the yarn configuration.
 func ConfigGet(key, executablePath string, jsonOutput bool) (string, error) {
 	var flags []string = nil
 	if jsonOutput {

artifactory/utils/yarn/versionVerify.go

@@ -0,0 +1,39 @@
+package yarn
+
+import (
+	gofrogcmd "github.com/jfrog/gofrog/io"
+	"github.com/jfrog/gofrog/version"
+	"github.com/jfrog/jfrog-client-go/utils/errorutils"
+	"strings"
+)
+
+const unsupportedYarnVersion = "4.0.0"
+
+func IsInstalledYarnVersionSupported(executablePath string) error {
+	versionGetCmdConfig := getVersionCmdConfig(executablePath)
+	output, err := gofrogcmd.RunCmdOutput(versionGetCmdConfig)
+	if err != nil {
+		return errorutils.CheckError(err)
+	}
+	yarnVersion := strings.TrimSpace(output)
+	return IsVersionSupported(yarnVersion)
+}
+
+func IsVersionSupported(versionStr string) error {
+	yarnVersion := version.NewVersion(versionStr)
+	if yarnVersion.Compare(unsupportedYarnVersion) <= 0 {
+		return errorutils.CheckErrorf("Yarn version 4 is not supported. The current version is: " + versionStr +
+			". Please downgrade to a compatible version to continue")
+	}
+	return nil
+}
+
+func getVersionCmdConfig(executablePath string) *YarnConfig {
+	return &YarnConfig{
+		Executable:   executablePath,
+		Command:      []string{"--version"},
+		CommandFlags: nil,
+		StrWriter:    nil,
+		ErrWriter:    nil,
+	}
+}

artifactory/utils/yarn/versionVerify_test.go

@@ -0,0 +1,26 @@
+package yarn
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestIsVersionSupported(t *testing.T) {
+	tests := []struct {
+		versionStr string
+		expectErr  bool
+	}{
+		{"3.9.0", false},
+		{"4.0.0", true},
+		{"4.1.0", true},
+	}
+
+	for _, test := range tests {
+		err := IsVersionSupported(test.versionStr)
+		if test.expectErr {
+			assert.Error(t, err, "Expected an error for version: %s", test.versionStr)
+		} else {
+			assert.NoError(t, err, "Did not expect an error for version: %s", test.versionStr)
+		}
+	}
+}