Update paths of moved values when inserting with $prepend (#127)

Author: fsteeg

metafix/src/main/java/org/metafacture/metafix/Value.java

@@ -439,8 +439,20 @@ public void add(final Value value) {
         }
 
         /* package-private */ void add(final int index, final Value value) {
+            add(index, value, true);
+        }
+
+        /* package-private */ void add(final int index, final Value value, final boolean appendToPath) {
             if (!isNull(value)) {
-                list.add(index, value);
+                list.add(index, appendToPath ? value.withPathAppend(index + 1) : value);
+                updateIndexesInPathsAfter(index);
+            }
+        }
+
+        private void updateIndexesInPathsAfter(final int start) {
+            for (int index = start + 1; index < list.size(); index = index + 1) {
+                final Value value = list.get(index);
+                value.withPathSet(value.getPath().replaceAll("\\d+$", String.valueOf(index + 1)));
             }
         }
 

metafix/src/test/java/org/metafacture/metafix/MetafixLookupTest.java

@@ -928,14 +928,23 @@ public void shouldLookupInNestedArrays() {
     }
 
     @Test
-    public void shouldLookupInCopiedNestedArrays() {
+    public void shouldLookupInCopiedNestedArraysCreatedWithAppend() {
+        shouldLookupInCopiedNestedArraysCreatedWith("$append");
+    }
+
+    @Test
+    public void shouldLookupInCopiedNestedArraysCreatedWithPrepend() {
+        shouldLookupInCopiedNestedArraysCreatedWith("$prepend");
+    }
+
+    private void shouldLookupInCopiedNestedArraysCreatedWith(final String reservedField) {
         MetafixTestHelpers.assertFix(streamReceiver, Arrays.asList(
                 "put_map('rswk-indicator', s: 'SubjectHeading')",
                 "set_array('subject[]')",
-                "set_array('subject[].$append.componentList[]')",
-                "set_array('subject[].$last.componentList[].$append.type[]')",
+                "set_array('subject[]." + reservedField + ".componentList[]')",
+                "set_array('subject[].$last.componentList[]." + reservedField + ".type[]')",
                 "do list(path: 'D', 'var': '$i')",
-                "  copy_field('$i', 'subject[].$last.componentList[].$last.type[].$append')",
+                "  copy_field('$i', 'subject[].$last.componentList[].$last.type[]." + reservedField + "')",
                 "end",
                 "lookup('subject[].*.componentList[].*.type[].*', 'rswk-indicator')",
                 "retain('subject[]')"