Added execute support for text based responses

without this change it's impossible to execute any custom method to assert a response for a body that is just text
with this change you can do it

fixes #150

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/JUnitMessagingMethodBodyBuilder.groovy

@@ -71,6 +71,11 @@ class JUnitMessagingMethodBodyBuilder extends MessagingMethodBodyBuilder {
 		return ""
 	}
 
+	@Override
+	protected String getResponseBodyPropertyComparisonString(String property, ExecutionProperty value) {
+		return ""
+	}
+
 	@Override
 	protected void processBodyElement(BlockBuilder blockBuilder, String property, ExecutionProperty exec) {
 		blockBuilder.addLine("${exec.insertValue("parsedJson.read('\\\$$property')")}")

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/JUnitMethodBodyBuilder.groovy

@@ -81,6 +81,11 @@ abstract class JUnitMethodBodyBuilder extends RequestProcessingMethodBodyBuilder
 		return "assertThat(responseBody${property}).${buildEscapedMatchesMethod(value)}"
 	}
 
+	@Override
+	protected String getResponseBodyPropertyComparisonString(String property, ExecutionProperty value) {
+		return value.insertValue("responseBody${property}")
+	}
+
 	@Override
 	protected void processBodyElement(BlockBuilder blockBuilder, String property, ExecutionProperty exec) {
 		blockBuilder.addLine("${exec.insertValue("parsedJson.read(\"\\\$$property\")")};")

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/MethodBodyBuilder.groovy

@@ -91,6 +91,12 @@ abstract class MethodBodyBuilder {
 	 */
 	protected abstract String getResponseBodyPropertyComparisonString(String property, Pattern value)
 
+	/**
+	 * Builds the code that for the given {@code property} will match it to
+	 * the given {@link ExecutionProperty} value
+	 */
+	protected abstract String getResponseBodyPropertyComparisonString(String property, ExecutionProperty value)
+
 	/**
 	 * Appends to the {@link BlockBuilder} the assertion for the given body element
 	 */

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SpockMessagingMethodBodyBuilder.groovy

@@ -53,7 +53,12 @@ class SpockMessagingMethodBodyBuilder extends MessagingMethodBodyBuilder {
 
 	@Override
 	protected String getResponseBodyPropertyComparisonString(String property, Pattern value) {
-		return null
+		return ""
+	}
+
+	@Override
+	protected String getResponseBodyPropertyComparisonString(String property, ExecutionProperty value) {
+		return ""
 	}
 
 	@Override

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SpockMethodRequestProcessingBodyBuilder.groovy

@@ -60,6 +60,11 @@ abstract class SpockMethodRequestProcessingBodyBuilder extends RequestProcessing
 		return "responseBody$property ${patternComparison(value)}"
 	}
 
+	@Override
+	protected String getResponseBodyPropertyComparisonString(String property, ExecutionProperty value) {
+		return value.insertValue("responseBody${property}")
+	}
+
 	@Override
 	protected void processBodyElement(BlockBuilder blockBuilder, String property, ExecutionProperty exec) {
 		blockBuilder.addLine("${exec.insertValue("parsedJson.read('\\\$$property')")}")

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/JaxRsClientMethodBuilderSpec.groovy

@@ -766,6 +766,29 @@ class JaxRsClientMethodBuilderSpec extends Specification implements WireMockStub
 			test.contains("assertThat(responseBody).matches(\".*\");")
 	}
 
+	@Issue('#150')
+	def "should support custom method execution in response"() {
+		given:
+			Contract contractDsl = Contract.make {
+				request {
+					method 'GET'
+					url '/get'
+				}
+				response {
+					status 200
+					status 200
+					body(value(stub("HELLO FROM STUB"), server(execute('foo($it)'))))
+				}
+			}
+			MethodBodyBuilder builder = new JaxRsClientJUnitMethodBodyBuilder(contractDsl, properties)
+			BlockBuilder blockBuilder = new BlockBuilder(" ")
+		when:
+			builder.then(blockBuilder)
+			def test = blockBuilder.toString()
+		then:
+			test.contains("foo(responseBody);")
+	}
+
 	private String stripped(String string) {
 		return string.stripMargin().stripIndent().replace('\t', '').replace('\n', '').replace(' ','')
 	}

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/MockMvcMethodBodyBuilderSpec.groovy

@@ -1645,4 +1645,27 @@ World.'''"""
 			test.contains("responseBody ==~ java.util.regex.Pattern.compile('.*')")
 	}
 
+	@Issue('#150')
+	def "should support custom method execution in response"() {
+		given:
+		Contract contractDsl = Contract.make {
+			request {
+				method 'GET'
+				url '/get'
+			}
+			response {
+				status 200
+				status 200
+				body(value(stub("HELLO FROM STUB"), server(execute('foo($it)'))))
+			}
+		}
+			MethodBodyBuilder builder = new MockMvcSpockMethodRequestProcessingBodyBuilder(contractDsl, properties)
+			BlockBuilder blockBuilder = new BlockBuilder(" ")
+		when:
+			builder.then(blockBuilder)
+			def test = blockBuilder.toString()
+		then:
+			test.contains("foo(responseBody)")
+	}
+
 }