added script support in aitm proxy for setting dynamic upstream proxy

Signed-off-by: RonniSkansing <rskansing@gmail.com>

backend/service/proxy_script_test.go

@@ -0,0 +1,32 @@
+package service
+
+import "testing"
+
+// TestValidateSessionScript checks that a config naming a session script is
+// only accepted when the Scripts feature is enabled on the instance.
+func TestValidateSessionScript(t *testing.T) {
+	cases := []struct {
+		name    string
+		script  string
+		enabled bool
+		wantErr bool
+	}{
+		{"empty script, feature off", "", false, false},
+		{"empty script, feature on", "", true, false},
+		{"whitespace script, feature off", "   ", false, false},
+		{"script set, feature on", "pick-proxy", true, false},
+		{"script set, feature off", "pick-proxy", false, true},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			m := &Proxy{ScriptEnabled: tc.enabled}
+			err := m.validateSessionScript(&ProxyServiceConfigYAML{Script: tc.script})
+			if tc.wantErr && err == nil {
+				t.Fatal("expected an error, got nil")
+			}
+			if !tc.wantErr && err != nil {
+				t.Fatalf("expected no error, got %v", err)
+			}
+		})
+	}
+}