feat(field): Adds field at the top of a type.

src/main/java/spoon/reflect/declaration/CtType.java

@@ -104,7 +104,16 @@ public interface CtType<T> extends CtNamedElement, CtTypeInformation, CtTypeMemb
  boolean isTopLevel();
 
  /**
- * add a Field
+ * Adds a field at the top of the type (before static block).
+ * Note that the position of these field will be negative to be written at the top of the type.
+ *
+ * @param field
+ * @return <tt>true</tt> if the field is added.
+ */
+ <F, C extends CtType<T>> C addFieldAtTop(CtField<F> field);
+
+ /**
+ * add a field at the end of the field list.
  *
  * @param field
  * @return <tt>true</tt> if this element changed as a result of the call

src/main/java/spoon/support/reflect/declaration/CtTypeImpl.java

@@ -16,6 +16,7 @@
  */
 package spoon.support.reflect.declaration;
 
+import spoon.reflect.cu.CompilationUnit;
 import spoon.reflect.declaration.CtAnnotation;
 import spoon.reflect.declaration.CtAnnotationType;
 import spoon.reflect.declaration.CtClass;
@@ -75,6 +76,22 @@ public CtTypeImpl() {
  super();
  }
 
+ @Override
+ public <F, C extends CtType<T>> C addFieldAtTop(CtField<F> field) {
+ if (!this.fields.contains(field)) {
+ field.setParent(this);
+ CompilationUnit compilationUnit = null;
+ if (getPosition() != null) {
+ compilationUnit = getPosition().getCompilationUnit();
+ }
+ field.setPosition(getFactory().Core().createSourcePosition(compilationUnit, -1, -1, -1, new int[0]));
+ this.fields.add(field);
+ }
+
+ // field already exists
+ return (C) this;
+ }
+
  @Override
  public <F, C extends CtType<T>> C addField(CtField<F> field) {
  if (!this.fields.contains(field)) {

src/test/java/spoon/test/field/FieldTest.java

@@ -19,13 +19,21 @@
 
 import org.junit.Test;
 import spoon.reflect.declaration.CtClass;
+import spoon.reflect.declaration.CtElement;
 import spoon.reflect.declaration.CtField;
 import spoon.reflect.declaration.ModifierKind;
 import spoon.reflect.factory.Factory;
+import spoon.support.reflect.cu.CtLineElementComparator;
+import spoon.support.util.SortedList;
+import spoon.test.field.testclasses.AddFieldAtTop;
 
+import java.io.File;
 import java.util.HashSet;
 
 import static org.junit.Assert.assertEquals;
+import static spoon.testing.Assert.assertThat;
+import static spoon.testing.utils.ModelUtils.build;
+import static spoon.testing.utils.ModelUtils.buildClass;
 import static spoon.testing.utils.ModelUtils.createFactory;
 
 public class FieldTest {
@@ -53,6 +61,30 @@ public void testAddAFieldInAClassAtAPositionGiven() throws Exception {
  assertEquals(second, fieldClass.getFields().get(2));
  }
 
+ @Test
+ public void testAddFieldsAtTop() throws Exception {
+ // contract: When we use CtType#addFieldAtTop, field added should be printed at the top of the type.
+ final CtClass<AddFieldAtTop> aClass = (CtClass<AddFieldAtTop>) buildClass(AddFieldAtTop.class);
+
+ assertEquals(1, aClass.getFields().size());
+
+ final CtField<String> generated = aClass.getFactory().Field().create(null, new HashSet<>(), aClass.getFactory().Type().STRING, "generated");
+ aClass.addFieldAtTop(generated);
+ final CtField<String> generated2 = aClass.getFactory().Field().create(null, new HashSet<>(), aClass.getFactory().Type().STRING, "generated2");
+ aClass.addFieldAtTop(generated2);
+
+ assertEquals(3, aClass.getFields().size());
+ // For now, DefaultJavaPrettyPrinter sorts elements according to their position.
+ final SortedList<CtElement> sorted = new SortedList<CtElement>(new CtLineElementComparator());
+ sorted.addAll(aClass.getFields());
+ sorted.addAll(aClass.getAnonymousExecutables());
+ assertEquals(generated, sorted.get(0));
+ assertEquals(generated2, sorted.get(1));
+ assertEquals(aClass.getAnonymousExecutables().get(0), sorted.get(2));
+
+ assertThat(aClass).isEqualTo(build(new File("./src/test/resources/expected/AddFieldAtTop.java")).Type().get("AddFieldAtTop"));
+ }
+
  private CtField<Integer> createField(Factory factory, HashSet<ModifierKind> modifiers, String name) {
  final CtField<Integer> first = factory.Core().createField();
  first.setModifiers(modifiers);

src/test/java/spoon/test/field/testclasses/AddFieldAtTop.java

@@ -0,0 +1,12 @@
+package spoon.test.field.testclasses;
+
+public class AddFieldAtTop {
+
+ static {
+ }
+
+ int i;
+
+ void m() {
+ }
+}

src/test/resources/expected/AddFieldAtTop.java

@@ -0,0 +1,13 @@
+public class AddFieldAtTop {
+ java.lang.String generated;
+
+ java.lang.String generated2;
+
+ static {
+ }
+
+ int i;
+
+ void m() {
+ }
+}