Added more tests and fixed a couple of bugs. Also formatted the code

lang/java/compiler/src/main/java/org/apache/avro/compiler/idl/ResolvingVisitor.java

@@ -16,7 +16,6 @@
  * this visitor will create a clone of the original Schema and will also resolve all unresolved schemas
  *
  * by default. what attributes are copied is customizable.
- * @author zoly
  */
 public final class ResolvingVisitor implements SchemaVisitor<Schema> {
 

lang/java/compiler/src/main/java/org/apache/avro/compiler/idl/SchemaResolver.java

@@ -16,12 +16,14 @@
 package org.apache.avro.compiler.idl;
 
 import avro.shaded.com.google.common.base.Function;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
+
 import org.apache.avro.Protocol;
 import org.apache.avro.Schema;
 import org.apache.avro.compiler.schema.Schemas;
@@ -44,46 +46,45 @@ private SchemaResolver() {
    * Create a schema to represent a "unresolved" schema.
    * (used to represent a schema where the definition is not known at the time)
    * This concept might be generalizable...
+   *
    * @param name
    * @return
    */
   static Schema unresolvedSchema(final String name) {
     Schema schema = Schema.createRecord(UR_SCHEMA_NAME, "unresolved schema",
-            UR_SCHEMA_NS, false, Collections.EMPTY_LIST);
+        UR_SCHEMA_NS, false, Collections.EMPTY_LIST);
     schema.addProp(UR_SCHEMA_ATTR, name);
     return schema;
   }
 
   /**
    * Is this a unresolved schema.
+   *
    * @param schema
    * @return
    */
   static boolean isUnresolvedSchema(final Schema schema) {
     return (schema.getType() == Schema.Type.RECORD && schema.getProp(UR_SCHEMA_ATTR) != null
-            && UR_SCHEMA_NAME.equals(schema.getName())
-            && UR_SCHEMA_NS.equals(schema.getNamespace()));
+        && UR_SCHEMA_NAME.equals(schema.getName())
+        && UR_SCHEMA_NS.equals(schema.getNamespace()));
   }
 
   /**
    * get the unresolved schema name.
+   *
    * @param schema
    * @return
    */
   static String getUnresolvedSchemaName(final Schema schema) {
     if (!isUnresolvedSchema(schema)) {
       throw new IllegalArgumentException("Not a unresolved schema: " + schema);
     }
-    String name = schema.getProp(UR_SCHEMA_ATTR);
-    if (name == null) {
-      throw new IllegalArgumentException("Schema " + schema + " must have attribute: " + UR_SCHEMA_ATTR);
-    } else {
-      return name;
-    }
+    return schema.getProp(UR_SCHEMA_ATTR);
   }
 
   /**
    * Will clone the provided protocol while resolving all unreferenced schemas
+   *
    * @param protocol
    * @return
    */
@@ -105,13 +106,13 @@ static Protocol resolve(final Protocol protocol) {
       if (value.isOneWay()) {
         Schema replacement = resolve(replacements, value.getRequest(), protocol);
         nvalue = result.createMessage(value.getName(), value.getDoc(),
-                value.getObjectProps(), replacement);
+            value.getObjectProps(), replacement);
       } else {
         Schema request = resolve(replacements, value.getRequest(), protocol);
         Schema response = resolve(replacements, value.getResponse(), protocol);
         Schema errors = resolve(replacements, value.getErrors(), protocol);
         nvalue = result.createMessage(value.getName(), value.getDoc(),
-                value.getObjectProps(), request, response, errors);
+            value.getObjectProps(), request, response, errors);
       }
       result.getMessages().put(entry.getKey(), nvalue);
     }
@@ -120,11 +121,11 @@ static Protocol resolve(final Protocol protocol) {
   }
 
   private static Schema resolve(final IdentityHashMap<Schema, Schema> replacements,
-          final Schema request, final Protocol protocol) {
+                                final Schema request, final Protocol protocol) {
     Schema replacement = replacements.get(request);
     if (replacement == null) {
       replacement = Schemas.visit(request, new ResolvingVisitor(request, replacements,
-              new SymbolTable(protocol)));
+          new SymbolTable(protocol)));
     }
     return replacement;
   }

lang/java/compiler/src/main/java/org/apache/avro/compiler/schema/CloningVisitor.java

@@ -4,13 +4,14 @@
 import java.util.ArrayList;
 import java.util.IdentityHashMap;
 import java.util.List;
+
 import org.apache.avro.Schema;
+
 import static org.apache.avro.Schema.Type.RECORD;
 
 /**
  * this visitor will create a clone of the original Schema with docs and other nonesential fields stripped
  * by default. what attributes are copied is customizable.
- * @author zoly
  */
 public final class CloningVisitor implements SchemaVisitor<Schema> {
 
@@ -24,11 +25,13 @@ public final class CloningVisitor implements SchemaVisitor<Schema> {
 
   public interface PropertyCopier {
     void copy(Schema first, Schema second);
+
     void copy(Schema.Field first, Schema.Field second);
   }
 
   /**
    * copy only serialization necessary fields.
+   *
    * @param root
    */
   public CloningVisitor(final Schema root) {
@@ -41,7 +44,7 @@ public void copy(final Schema first, final Schema second) {
 
       @Override
       public void copy(final Schema.Field first, final Schema.Field second) {
-         Schemas.copyAliases(first, second);
+        Schemas.copyAliases(first, second);
       }
     }, false, root);
   }
@@ -74,14 +77,14 @@ public SchemaVisitorAction visitTerminal(final Schema terminal) {
       case NULL:
       case STRING:
         newSchema = Schema.create(type);
-      break;
+        break;
       case ENUM:
         newSchema = Schema.createEnum(terminal.getName(), copyDocs ? terminal.getDoc() : null,
-                terminal.getNamespace(), terminal.getEnumSymbols());
+            terminal.getNamespace(), terminal.getEnumSymbols());
         break;
       case FIXED:
         newSchema = Schema.createFixed(terminal.getName(), copyDocs ? terminal.getDoc() : null,
-                terminal.getNamespace(), terminal.getFixedSize());
+            terminal.getNamespace(), terminal.getFixedSize());
         break;
       default:
         throw new IllegalStateException("Unsupported schema " + terminal);
@@ -94,52 +97,52 @@ public SchemaVisitorAction visitTerminal(final Schema terminal) {
   @Override
   public SchemaVisitorAction visitNonTerminal(final Schema nt) {
     Schema.Type type = nt.getType();
-    if  (type == RECORD) {
-        Schema newSchema = Schema.createRecord(nt.getName(), copyDocs ? nt.getDoc() : null,
-                nt.getNamespace(), nt.isError());
-        copyProperties.copy(nt, newSchema);
-        replace.put(nt, newSchema);
+    if (type == RECORD) {
+      Schema newSchema = Schema.createRecord(nt.getName(), copyDocs ? nt.getDoc() : null,
+          nt.getNamespace(), nt.isError());
+      copyProperties.copy(nt, newSchema);
+      replace.put(nt, newSchema);
     }
     return SchemaVisitorAction.CONTINUE;
   }
 
   @Override
   public SchemaVisitorAction afterVisitNonTerminal(final Schema nt) {
-     Schema.Type type = nt.getType();
-     Schema newSchema;
-     switch (type) {
-       case RECORD:
-         newSchema = replace.get(nt);
-         List<Schema.Field> fields = nt.getFields();
-         List<Schema.Field> newFields = new ArrayList<Schema.Field>(fields.size());
-         for (Schema.Field field : fields) {
+    Schema.Type type = nt.getType();
+    Schema newSchema;
+    switch (type) {
+      case RECORD:
+        newSchema = replace.get(nt);
+        List<Schema.Field> fields = nt.getFields();
+        List<Schema.Field> newFields = new ArrayList<Schema.Field>(fields.size());
+        for (Schema.Field field : fields) {
           Schema.Field newField = new Schema.Field(field.name(), replace.get(field.schema()),
-                  copyDocs ? field.doc() : null, field.defaultVal(), field.order());
+              copyDocs ? field.doc() : null, field.defaultVal(), field.order());
           copyProperties.copy(field, newField);
           newFields.add(newField);
-         }
-         newSchema.setFields(newFields);
-         return SchemaVisitorAction.CONTINUE;
-       case UNION:
-          List<Schema> types = nt.getTypes();
-          List<Schema> newTypes = new ArrayList<Schema>(types.size());
-          for (Schema sch : types) {
-            newTypes.add(replace.get(sch));
-          }
-          newSchema = Schema.createUnion(newTypes);
-          break;
-       case ARRAY:
-         newSchema = Schema.createArray(replace.get(nt.getElementType()));
-         break;
-       case MAP:
-         newSchema = Schema.createMap(replace.get(nt.getValueType()));
-         break;
-       default:
-         throw new IllegalStateException("Illegal type " + type + ", schema " + nt);
-     }
-     copyProperties.copy(nt, newSchema);
-     replace.put(nt, newSchema);
-     return SchemaVisitorAction.CONTINUE;
+        }
+        newSchema.setFields(newFields);
+        return SchemaVisitorAction.CONTINUE;
+      case UNION:
+        List<Schema> types = nt.getTypes();
+        List<Schema> newTypes = new ArrayList<Schema>(types.size());
+        for (Schema sch : types) {
+          newTypes.add(replace.get(sch));
+        }
+        newSchema = Schema.createUnion(newTypes);
+        break;
+      case ARRAY:
+        newSchema = Schema.createArray(replace.get(nt.getElementType()));
+        break;
+      case MAP:
+        newSchema = Schema.createMap(replace.get(nt.getValueType()));
+        break;
+      default:
+        throw new IllegalStateException("Illegal type " + type + ", schema " + nt);
+    }
+    copyProperties.copy(nt, newSchema);
+    replace.put(nt, newSchema);
+    return SchemaVisitorAction.CONTINUE;
   }
 
   @Override

lang/java/compiler/src/main/java/org/apache/avro/compiler/schema/SchemaVisitor.java

@@ -1,47 +1,47 @@
- /*
- * Copyright (c) 2001 - 2016, Zoltan Farkas All Rights Reserved.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
- */
+/*
+* Copyright (c) 2001 - 2016, Zoltan Farkas All Rights Reserved.
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this program; if not, write to the Free Software
+* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+*/
 package org.apache.avro.compiler.schema;
 
 import org.apache.avro.Schema;
 
-/**
- * @author zoly
- */
 public interface SchemaVisitor<T> {
 
   /**
    * Invoked for schemas that do not have "child" schemas (like string, int ...)
    * or for a previously encountered schema with children,
    * which will be treated as a terminal. (to avoid circular recursion)
+   *
    * @param terminal
    * @return
    */
   SchemaVisitorAction visitTerminal(Schema terminal);
 
   /**
    * Invoked for schema with children before proceeding to visit the children.
+   *
    * @param nonTerminal
    * @return
    */
   SchemaVisitorAction visitNonTerminal(Schema nonTerminal);
 
   /**
    * Invoked for schemas with children after its children have been visited.
+   *
    * @param nonTerminal
    * @return
    */
@@ -50,6 +50,7 @@ public interface SchemaVisitor<T> {
 
   /**
    * Invoked when visiting is complete.
+   *
    * @return a value which will be returned by the visit method.
    */
   T get();