#9401 JSON converter should maintain order of one-to-many relations

Author: houbie

grails-plugin-converters/src/main/groovy/org/grails/web/converters/marshaller/json/DomainClassMarshaller.java

@@ -18,17 +18,7 @@
 import grails.converters.JSON;
 import groovy.lang.GroovyObject;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.SortedMap;
-import java.util.SortedSet;
-import java.util.TreeMap;
-import java.util.TreeSet;
+import java.util.*;
 
 import org.grails.core.util.ClassPropertyFetcher;
 import org.grails.core.artefact.DomainClassArtefactHandler;
@@ -148,10 +138,10 @@ else if (referenceObject instanceof SortedSet) {
                             referenceObject = new TreeSet((SortedSet) referenceObject);
                         }
                         else if (referenceObject instanceof Set) {
-                            referenceObject = new HashSet((Set) referenceObject);
+                            referenceObject = new LinkedHashSet((Set) referenceObject);
                         }
                         else if (referenceObject instanceof Map) {
-                            referenceObject = new HashMap((Map) referenceObject);
+                            referenceObject = new LinkedHashMap((Map) referenceObject);
                         }
                         else if (referenceObject instanceof Collection) {
                             referenceObject = new ArrayList((Collection) referenceObject);

grails-plugin-converters/src/main/groovy/org/grails/web/converters/marshaller/xml/DomainClassMarshaller.java

@@ -118,10 +118,10 @@ else if (referenceObject instanceof SortedSet) {
                             referenceObject = new TreeSet((SortedSet) referenceObject);
                         }
                         else if (referenceObject instanceof Set) {
-                            referenceObject = new HashSet((Set) referenceObject);
+                            referenceObject = new LinkedHashSet((Set) referenceObject);
                         }
                         else if (referenceObject instanceof Map) {
-                            referenceObject = new HashMap((Map) referenceObject);
+                            referenceObject = new LinkedHashMap((Map) referenceObject);
                         }
                         else if (referenceObject instanceof Collection) {
                             referenceObject = new ArrayList((Collection) referenceObject);

grails-plugin-converters/src/test/groovy/org/grails/web/converters/marshaller/json/DomainClassMarshallerSpec.groovy

@@ -0,0 +1,63 @@
+package org.grails.web.converters.marshaller.json
+
+import grails.converters.JSON
+import grails.converters.XML
+import grails.core.DefaultGrailsApplication
+import grails.persistence.Entity
+import org.grails.web.converters.configuration.ConvertersConfigurationInitializer
+import spock.lang.Specification
+
+class DomainClassMarshallerSpec extends Specification {
+    void setup() {
+        final initializer = new ConvertersConfigurationInitializer()
+        def grailsApplication = new DefaultGrailsApplication(Author, Book)
+        grailsApplication.initialise()
+        initializer.grailsApplication = grailsApplication
+        initializer.initialize()
+    }
+
+    void "Test DomainClassMarshaller's should maintain order of relations"() {
+        def json, xml
+
+        when:
+        def book = new Book(
+                id: 1, version: 2,
+                authorsSet: authors as Set,
+                authorsMap: authors.inject([:]) { acc, val ->
+                    acc[val.name] = val
+                    acc
+                }
+        )
+        JSON.use('deep') {
+            json = book as JSON
+        }
+        XML.use('deep') {
+            xml = book as XML
+        }
+
+        then:
+        json.toString() == expectedJson
+        xml.toString() == expectedXml
+
+        where:
+        authors                                                      | expectedJson                                                                                                                     | expectedXml
+        [new Author(id: 1, name: 'a'), new Author(id: 2, name: 'b')] | '{"id":1,"authorsMap":{"a":{"id":1,"name":"a"},"b":{"id":2,"name":"b"}},"authorsSet":[{"id":1,"name":"a"},{"id":2,"name":"b"}]}' | '<?xml version="1.0" encoding="UTF-8"?><book id="1"><authorsMap><entry key="a" id="1"><name>a</name></entry><entry key="b" id="2"><name>b</name></entry></authorsMap><authorsSet><author id="1"><name>a</name></author><author id="2"><name>b</name></author></authorsSet></book>'
+        [new Author(id: 2, name: 'b'), new Author(id: 1, name: 'a')] | '{"id":1,"authorsMap":{"b":{"id":2,"name":"b"},"a":{"id":1,"name":"a"}},"authorsSet":[{"id":2,"name":"b"},{"id":1,"name":"a"}]}' | '<?xml version="1.0" encoding="UTF-8"?><book id="1"><authorsMap><entry key="b" id="2"><name>b</name></entry><entry key="a" id="1"><name>a</name></entry></authorsMap><authorsSet><author id="2"><name>b</name></author><author id="1"><name>a</name></author></authorsSet></book>'
+    }
+}
+
+@Entity
+class Author {
+    Long id
+    Long version
+    String name
+}
+
+@Entity
+class Book {
+    static hasMany = [authorsSet: Author, authorsMap: Author]
+    Long id
+    Long version
+    Set authorsSet
+    Map authorsMap
+}