Allow VEnum types in the concat() function

core/formula/src/main/java/org/csstudio/apputil/formula/string/StringConcatFunction.java

@@ -3,12 +3,7 @@
 
 import org.csstudio.apputil.formula.spi.FormulaFunction;
 import org.epics.util.array.ListNumber;
-import org.epics.vtype.Alarm;
-import org.epics.vtype.Time;
-import org.epics.vtype.VNumberArray;
-import org.epics.vtype.VString;
-import org.epics.vtype.VStringArray;
-import org.epics.vtype.VType;
+import org.epics.vtype.*;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -56,19 +51,22 @@ public VType compute(VType... args) throws Exception {
             } else if (isString(arg))
             {
                 stringBuilder.append(((VString)arg).getValue());
+            } else if (isEnum(arg))
+            {
+                stringBuilder.append(((VEnum)arg).getValue());
             }
         });
         return VString.of(stringBuilder.toString(), Alarm.none(), Time.now());
     }
 
     /**
      * Returns true is the value is a StringArray or can be converted to a StringArray
-     * @param value 
+     * @param value
      * @return boolean true if value can be used as a string array
      */
     private boolean isStringArray(VType value)
     {
-        return value instanceof VStringArray 
+        return value instanceof VStringArray
             || value instanceof VNumberArray;
     }
 
@@ -93,4 +91,9 @@ private boolean isString(VType value)
     {
         return value instanceof VString;
     }
+
+    private boolean isEnum(VType value)
+    {
+        return value instanceof VEnum;
+    }
 }

core/formula/src/test/java/org/csstudio/apputil/formula/string/StringConcatFunctionTest.java

@@ -0,0 +1,69 @@
+package org.csstudio.apputil.formula.string;
+
+import org.epics.util.array.ArrayDouble;
+import org.epics.vtype.*;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class StringConcatFunctionTest {
+
+    @Test
+    void concatStrings() throws Exception {
+        StringConcatFunction concatFunction = new StringConcatFunction();
+
+        VString a = VString.of("a", Alarm.none(), Time.now());
+        VString b = VString.of("b", Alarm.none(), Time.now());
+        VString c = VString.of("c", Alarm.none(), Time.now());
+
+        VString res = (VString) concatFunction.compute(a,b,c);
+        assertEquals("abc", res.getValue());
+    }
+
+    @Test
+    void concatStringArray() throws Exception {
+        StringConcatFunction concatFunction = new StringConcatFunction();
+
+        VType array = VStringArray.of(Arrays.asList("a", "b", "c"), Alarm.none(), Time.now());
+
+        VString res = (VString) concatFunction.compute(array);
+        assertEquals("abc", res.getValue());
+    }
+
+    @Test
+    void concatDoubleArray() throws Exception {
+        StringConcatFunction concatFunction = new StringConcatFunction();
+
+        VType array = VNumberArray.of(ArrayDouble.of(1.0, 2.0, 3.0), Alarm.none(), Time.now(), Display.none());
+
+        VString res = (VString) concatFunction.compute(array);
+        assertEquals("1.02.03.0", res.getValue());
+    }
+
+    @Test
+    void concatInvalidVType() throws Exception {
+        StringConcatFunction concatFunction = new StringConcatFunction();
+
+        VType num1 = VNumber.of(1.0, Alarm.none(), Time.now(), Display.none());
+        VType num2 = VNumber.of(2.0, Alarm.none(), Time.now(), Display.none());
+        VType num3 = VNumber.of(3.0, Alarm.none(), Time.now(), Display.none());
+
+        VString res = (VString) concatFunction.compute(num1, num2, num3);
+        // Will not attempt to concat and will return empty string
+        assertEquals("", res.getValue());
+    }
+
+    @Test
+    void concatEnums() throws Exception {
+        StringConcatFunction concatFunction = new StringConcatFunction();
+
+        VEnum enum1 = VEnum.of(0, EnumDisplay.of("a", "b", "c"), Alarm.none(), Time.now());
+        VEnum enum2 = VEnum.of(1, EnumDisplay.of("a", "b", "c"), Alarm.none(), Time.now());
+        VEnum enum3 = VEnum.of(2, EnumDisplay.of("a", "b", "c"), Alarm.none(), Time.now());
+
+        VString res = (VString) concatFunction.compute(enum1, enum2, enum3);
+        assertEquals("abc", res.getValue());
+    }
+}