single version of request.setGSON so operator form works regardless o…

…f argument type

Fixes #31

src/groovy/grails/plugin/gson/test/GsonUnitTestMixin.groovy

@@ -7,6 +7,7 @@ import grails.plugin.gson.api.ArtefactEnhancer
 import grails.plugin.gson.spring.GsonBuilderFactory
 import grails.plugin.gson.support.proxy.DefaultEntityProxyHandler
 import grails.test.mixin.support.GrailsUnitTestMixin
+import org.codehaus.groovy.grails.web.converters.Converter
 import org.junit.*
 
 class GsonUnitTestMixin extends GrailsUnitTestMixin {
@@ -49,13 +50,15 @@ class GsonUnitTestMixin extends GrailsUnitTestMixin {
 
 		def parser = new JsonParser()
 
-		HttpServletRequest.metaClass.setGSON = { JsonElement json ->
+		HttpServletRequest.metaClass.setGSON = { json ->
+			if (json instanceof Converter) {
+				json = json.toString()
+			}
+			if (json instanceof CharSequence) {
+				json = parser.parse(json.toString())
+			}
 			delegate.contentType = 'application/json'
-			delegate.content = new Gson().toJson(json).getBytes('UTF-8')
-		}
-
-		HttpServletRequest.metaClass.setGSON = { CharSequence json ->
-			delegate.setGSON parser.parse(json.toString())
+			delegate.content = gsonBuilder.create().toJson(json).getBytes('UTF-8')
 		}
 
 		HttpServletResponse.metaClass.getGSON = {->

test/apps/gson-test/test/unit/grails/plugin/gson/test/UnitTestSupportSpec.groovy

@@ -1,5 +1,8 @@
 package grails.plugin.gson.test
 
+import com.google.gson.Gson
+import grails.converters.JSON
+import grails.plugin.gson.converters.GSON
 import grails.test.mixin.*
 import spock.lang.*
 import static javax.servlet.http.HttpServletResponse.SC_CREATED
@@ -8,6 +11,7 @@ import static javax.servlet.http.HttpServletResponse.SC_CREATED
 @TestFor(AlbumController)
 @TestMixin(GsonUnitTestMixin)
 @Mock([Artist, Album])
+@Unroll
 class UnitTestSupportSpec extends Specification {
 
 	Artist artist
@@ -49,4 +53,26 @@ class UnitTestSupportSpec extends Specification {
 		album.artist.name == artist.name
 	}
 
+	@Shared def data = [title: "The Next Day", artist: [name: "David Bowie"]]
+
+	void 'can assign #type to request.GSON'() {
+		when:
+		request.GSON = body
+
+		then:
+		request.GSON.title.asString == data.title
+		request.GSON.artist.name.asString == data.artist.name
+
+		where:
+		body << [
+				new Gson().toJson(data),
+				data,
+				new Gson().toJsonTree(data),
+				data as GSON,
+				data as JSON
+		]
+
+		type = body.getClass().simpleName
+	}
+
 }