introduce a moveField jsonata function #126

dashjoin-core/src/main/java/org/dashjoin/function/MoveField.java

@@ -0,0 +1,51 @@
+package org.dashjoin.function;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * $moveField(object, from, to) removes the key "from" from object and inserts it in "to". If to is
+ * an object, the removed key is added to it. If to is an array, the removed key is added to each
+ * array element (if that is an object)
+ */
+@SuppressWarnings("rawtypes")
+public class MoveField extends AbstractVarArgFunction<Object> {
+
+  @SuppressWarnings("unchecked")
+  @Override
+  public Object run(List arg) throws Exception {
+
+    Map object = (Map) arg.get(0);
+    String from = (String) arg.get(1);
+    String to = (String) arg.get(2);
+    Object f = object.remove(from);
+    Object t = object.get(to);
+    if (t instanceof List) {
+      List l = (List) t;
+      for (Object i : l)
+        if (i instanceof Map)
+          ((Map) i).put(from, f);
+    }
+    if (t instanceof Map) {
+      Map m = (Map) t;
+      m.put(from, f);
+    }
+    return object;
+  }
+
+  @Override
+  public String getID() {
+    return "moveField";
+  }
+
+  @Override
+  public String getType() {
+    return "read";
+  }
+
+  @Override
+  public List<Class> getArgumentClassList() {
+    return Arrays.asList(Object.class, String.class, String.class);
+  }
+}

dashjoin-core/src/main/resources/META-INF/services/org.dashjoin.function.Function

@@ -25,3 +25,4 @@ org.dashjoin.function.Index
 org.dashjoin.function.Table2Object
 org.dashjoin.function.IsRecursiveTrigger
 org.dashjoin.function.Excel2data
+org.dashjoin.function.MoveField

dashjoin-core/src/test/java/org/dashjoin/function/MoveFieldTest.java

@@ -0,0 +1,31 @@
+package org.dashjoin.function;
+
+import static java.util.Arrays.asList;
+import static org.dashjoin.util.MapUtil.of;
+import java.util.Arrays;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class MoveFieldTest {
+
+  @Test
+  public void testIgoreIfToIsNoObject() throws Exception {
+    MoveField m = new MoveField();
+    Object res = m.run(Arrays.asList(of("x", 1, "y", asList(1)), "x", "y"));
+    Assertions.assertEquals("{y=[1]}", "" + res);
+  }
+
+  @Test
+  public void testMoveToArray() throws Exception {
+    MoveField m = new MoveField();
+    Object res = m.run(Arrays.asList(of("x", 1, "y", asList(of(), of())), "x", "y"));
+    Assertions.assertEquals("{y=[{x=1}, {x=1}]}", "" + res);
+  }
+
+  @Test
+  public void testMoveToMap() throws Exception {
+    MoveField m = new MoveField();
+    Object res = m.run(Arrays.asList(of("x", 1, "y", of()), "x", "y"));
+    Assertions.assertEquals("{y={x=1}}", "" + res);
+  }
+}