Add ObjectMapper unescaping ASCII control characters when using DTOs

core/src/main/kotlin/org/evomaster/core/output/dto/DtoOutput.kt

@@ -1,7 +1,5 @@
 package org.evomaster.core.output.dto
 
-import org.evomaster.core.output.Lines
-import org.evomaster.core.output.OutputFormat
 import java.nio.file.Path
 
 /**
@@ -12,12 +10,22 @@ import java.nio.file.Path
 interface DtoOutput {
 
     /**
+     * Writes a DTO class in the corresponding [org.evomaster.core.output.OutputFormat].
+     *
      * @param testSuitePath under which the java class must be written
      * @param testSuitePackage under which the java class must be written
-     * @param outputFormat forwarded to the [Lines] helper class and for setting the .java extension in the generated file
      * @param dtoClass to be written to filesystem
      */
-    fun writeClass(testSuitePath: Path, testSuitePackage: String, outputFormat: OutputFormat, dtoClass: DtoClass)
+    fun writeClass(testSuitePath: Path, testSuitePackage: String, dtoClass: DtoClass)
+
+    /**
+     * Writes an ObjectMapper class in the corresponding [org.evomaster.core.output.OutputFormat] for
+     * Jackson/RestAssured to use when serializing DTOs.
+     *
+     * @param testSuitePath under which the class must be written
+     * @param testSuitePackage under which the class must be written
+     */
+    fun writeObjectMapperClass(testSuitePath: Path, testSuitePackage: String)
 
     /**
      * @param dtoName that will be instantiated for payload

core/src/main/kotlin/org/evomaster/core/output/dto/DtoWriter.kt

@@ -49,25 +49,15 @@ class DtoWriter(
 
     fun write(testSuitePath: Path, testSuitePackage: String, solution: Solution<*>) {
         calculateDtos(solution)
+        val dtoOutput = when {
+            outputFormat.isJava() -> JavaDtoOutput(outputFormat)
+            outputFormat.isKotlin() -> KotlinDtoOutput(outputFormat)
+            else -> throw IllegalStateException("$outputFormat output format does not support DTOs as request payloads.")
+        }
         dtoCollector.forEach {
-            when {
-                outputFormat.isJava() -> JavaDtoOutput().writeClass(
-                    testSuitePath,
-                    testSuitePackage,
-                    outputFormat,
-                    it.value
-                )
-
-                outputFormat.isKotlin() -> KotlinDtoOutput().writeClass(
-                    testSuitePath,
-                    testSuitePackage,
-                    outputFormat,
-                    it.value
-                )
-
-                else -> throw IllegalStateException("$outputFormat output format does not support DTOs as request payloads.")
-            }
+            dtoOutput.writeClass(testSuitePath, testSuitePackage, it.value)
         }
+        dtoOutput.writeObjectMapperClass(testSuitePath, testSuitePackage)
     }
 
     fun containsDtos(): Boolean {

core/src/main/kotlin/org/evomaster/core/output/dto/GeneToDto.kt

@@ -31,9 +31,9 @@ class GeneToDto(
 ) {
 
     private var dtoOutput: DtoOutput = if (outputFormat.isJava()) {
-        JavaDtoOutput()
+        JavaDtoOutput(outputFormat)
     } else if (outputFormat.isKotlin()){
-        KotlinDtoOutput()
+        KotlinDtoOutput(outputFormat)
     } else {
         throw IllegalStateException("$outputFormat output format does not support DTOs as request payloads.")
     }

core/src/main/kotlin/org/evomaster/core/output/dto/JavaDtoOutput.kt

@@ -6,19 +6,28 @@ import org.evomaster.core.output.TestSuiteFileName
 import org.evomaster.core.utils.StringUtils
 import java.nio.file.Path
 
-class JavaDtoOutput: JvmDtoOutput() {
+class JavaDtoOutput(val outputFormat: OutputFormat): JvmDtoOutput() {
 
-    override fun writeClass(testSuitePath: Path, testSuitePackage: String, outputFormat: OutputFormat, dtoClass: DtoClass) {
+    override fun writeClass(testSuitePath: Path, testSuitePackage: String, dtoClass: DtoClass) {
         val dtoFilename = TestSuiteFileName(appendDtoPackage(dtoClass.name))
         val lines = Lines(outputFormat)
         setPackage(lines, testSuitePackage)
         addImports(lines)
-        initClass(lines, dtoFilename.getClassName())
+        initDtoClass(lines, dtoFilename.getClassName())
         addClassContent(lines, dtoClass)
         closeClass(lines)
         saveToDisk(lines.toString(), getTestSuitePath(testSuitePath, dtoFilename, outputFormat))
     }
 
+    override fun writeObjectMapperClass(testSuitePath: Path, testSuitePackage: String) {
+        val mapperFilename = TestSuiteFileName(appendDtoPackage(customControlCharMapperFactory))
+        val lines = Lines(outputFormat)
+        setPackage(lines, testSuitePackage)
+        addMapperImports(lines)
+        addMapperContentClass(lines)
+        saveToDisk(lines.toString(), getTestSuitePath(testSuitePath, mapperFilename, outputFormat))
+    }
+
     override fun getNewObjectStatement(dtoName: String, dtoVarName: String): String {
         return "$dtoName $dtoVarName = new $dtoName();"
     }
@@ -35,7 +44,7 @@ class JavaDtoOutput: JvmDtoOutput() {
         return "$listVarName.add($value);"
     }
 
-    private fun initClass(lines: Lines, dtoFilename: String) {
+    private fun initDtoClass(lines: Lines, dtoFilename: String) {
         lines.add("@JsonInclude(JsonInclude.Include.NON_NULL)")
         lines.add("public class $dtoFilename {")
         lines.addEmpty()
@@ -81,4 +90,56 @@ class JavaDtoOutput: JvmDtoOutput() {
             lines.addEmpty()
         }
     }
+
+    private fun addMapperContentClass(lines: Lines) {
+        lines.add("public class $customControlCharMapperFactory implements Jackson2ObjectMapperFactory {")
+        lines.addEmpty()
+        lines.indented {
+            lines.add("@Override")
+            lines.add("public ObjectMapper create(Type cls, String charset) {")
+            lines.indented {
+                lines.add("ObjectMapper mapper = new ObjectMapper();")
+                lines.add("mapper.registerModule(new Jdk8Module());")
+                lines.add("mapper.getFactory().setCharacterEscapes(new NoEscapeControlChars());")
+                lines.add("return mapper;")
+            }
+            lines.add("}")
+        }
+        lines.addEmpty()
+        lines.add("}")
+        lines.addEmpty()
+        lines.add("class NoEscapeControlChars extends CharacterEscapes {")
+        lines.addEmpty()
+        lines.indented {
+            lines.add("private final int[] escapes;")
+            lines.addEmpty()
+            lines.add("public NoEscapeControlChars() {")
+            lines.indented {
+                lines.add("int[] std = CharacterEscapes.standardAsciiEscapesForJSON();")
+                lines.add("escapes = java.util.Arrays.copyOf(std, std.length);")
+                lines.add("for (int i = 0; i < 0x20; i++) {")
+                    lines.indented {
+                        lines.add("escapes[i] = CharacterEscapes.ESCAPE_NONE;")
+                    }
+                lines.add("}")
+            }
+            lines.add("}")
+            lines.addEmpty()
+            lines.add("@Override")
+            lines.add("public int[] getEscapeCodesForAscii() {")
+            lines.indented {
+                lines.add("return escapes;")
+            }
+            lines.add("}")
+            lines.addEmpty()
+            lines.add("@Override")
+            lines.add("public SerializableString getEscapeSequence(int ch) {")
+            lines.indented {
+                lines.add("return null;")
+            }
+            lines.add("}")
+            lines.addEmpty()
+        }
+        lines.add("}")
+    }
 }

core/src/main/kotlin/org/evomaster/core/output/dto/JvmDtoOutput.kt

@@ -8,6 +8,8 @@ import java.nio.file.Path
 
 abstract class JvmDtoOutput: DtoOutput {
 
+    val customControlCharMapperFactory = "CustomControlCharMapperFactory"
+
     protected fun setPackage(lines: Lines, suitePackage: String) {
         val pkgPrefix = if (suitePackage.isNotEmpty()) "$suitePackage." else ""
         lines.addStatement("package ${pkgPrefix}dto")
@@ -23,6 +25,17 @@ abstract class JvmDtoOutput: DtoOutput {
         lines.addEmpty()
     }
 
+    protected fun addMapperImports(lines: Lines) {
+        lines.addStatement("import com.fasterxml.jackson.core.SerializableString")
+        lines.addStatement("import com.fasterxml.jackson.core.io.CharacterEscapes")
+        lines.addStatement("import com.fasterxml.jackson.databind.ObjectMapper")
+        lines.addStatement("import com.fasterxml.jackson.datatype.jdk8.Jdk8Module")
+        lines.addEmpty()
+        lines.addStatement("import io.restassured.path.json.mapper.factory.Jackson2ObjectMapperFactory")
+        lines.addStatement("import java.lang.reflect.Type")
+        lines.addEmpty()
+    }
+
     protected fun appendDtoPackage(name: String): String {
         return "dto.$name"
     }

core/src/main/kotlin/org/evomaster/core/output/dto/KotlinDtoOutput.kt

@@ -5,17 +5,26 @@ import org.evomaster.core.output.OutputFormat
 import org.evomaster.core.output.TestSuiteFileName
 import java.nio.file.Path
 
-class KotlinDtoOutput: JvmDtoOutput() {
+class KotlinDtoOutput(val outputFormat: OutputFormat): JvmDtoOutput() {
 
-    override fun writeClass(testSuitePath: Path, testSuitePackage: String, outputFormat: OutputFormat, dtoClass: DtoClass) {
+    override fun writeClass(testSuitePath: Path, testSuitePackage: String, dtoClass: DtoClass) {
         val dtoFilename = TestSuiteFileName(appendDtoPackage(dtoClass.name))
         val lines = Lines(outputFormat)
         setPackage(lines, testSuitePackage)
         addImports(lines)
-        declareClass(lines, dtoFilename.getClassName(), dtoClass)
+        declareDtoClass(lines, dtoFilename.getClassName(), dtoClass)
         saveToDisk(lines.toString(), getTestSuitePath(testSuitePath, dtoFilename, outputFormat))
     }
 
+    override fun writeObjectMapperClass(testSuitePath: Path, testSuitePackage: String) {
+        val mapperFilename = TestSuiteFileName(appendDtoPackage(customControlCharMapperFactory))
+        val lines = Lines(outputFormat)
+        setPackage(lines, testSuitePackage)
+        addMapperImports(lines)
+        addMapperContentClass(lines)
+        saveToDisk(lines.toString(), getTestSuitePath(testSuitePath, mapperFilename, outputFormat))
+    }
+
     override fun getNewObjectStatement(dtoName: String, dtoVarName: String): String {
         return "val $dtoVarName = $dtoName()"
     }
@@ -32,7 +41,7 @@ class KotlinDtoOutput: JvmDtoOutput() {
         return "$listVarName.add($value)"
     }
 
-    private fun declareClass(lines: Lines, dtoFilename: String, dtoClass: DtoClass) {
+    private fun declareDtoClass(lines: Lines, dtoFilename: String, dtoClass: DtoClass) {
         lines.add("@JsonInclude(JsonInclude.Include.NON_NULL)")
         lines.add("class $dtoFilename(")
         addVariables(lines, dtoClass)
@@ -49,4 +58,53 @@ class KotlinDtoOutput: JvmDtoOutput() {
         }
     }
 
+    private fun addMapperContentClass(lines: Lines) {
+        lines.add("class $customControlCharMapperFactory : Jackson2ObjectMapperFactory {")
+        lines.addEmpty()
+        lines.indented {
+            lines.add("override fun create(cls: Type, charset: String): ObjectMapper {")
+            lines.indented {
+                lines.add("val mapper = ObjectMapper()")
+                lines.add("mapper.registerModule(Jdk8Module())")
+                lines.add("mapper.factory.setCharacterEscapes(NoEscapeControlChars())")
+                lines.add("return mapper")
+            }
+            lines.add("}")
+        }
+        lines.addEmpty()
+        lines.add("}")
+        lines.addEmpty()
+        lines.add("class NoEscapeControlChars : CharacterEscapes() {")
+        lines.addEmpty()
+        lines.indented {
+            lines.add("private val escapes: IntArray")
+            lines.addEmpty()
+            lines.add("init {")
+            lines.indented {
+                lines.add("val std = CharacterEscapes.standardAsciiEscapesForJSON()")
+                lines.add("escapes = std.copyOf(std.size)")
+                lines.add("for (i in 0..0x1f) {")
+                lines.indented {
+                    lines.add("escapes[i] = CharacterEscapes.ESCAPE_NONE")
+                }
+                lines.add("}")
+            }
+            lines.add("}")
+            lines.addEmpty()
+            lines.add("override fun getEscapeCodesForAscii(): IntArray {")
+            lines.indented {
+                lines.add("return escapes")
+            }
+            lines.add("}")
+            lines.addEmpty()
+            lines.add("override fun getEscapeSequence(ch: Int): SerializableString? {")
+            lines.indented {
+                lines.add("return null")
+            }
+            lines.add("}")
+            lines.addEmpty()
+        }
+        lines.add("}")
+    }
+
 }

core/src/main/kotlin/org/evomaster/core/output/service/TestSuiteWriter.kt

@@ -439,6 +439,7 @@ class TestSuiteWriter {
                 val pkgPrefix = if (name.getPackage().isNotEmpty()) "${name.getPackage()}." else ""
                 addImport("${pkgPrefix}dto.*", lines)
                 addImport("java.util.ArrayList", lines)
+                addImport("io.restassured.config.ObjectMapperConfig", lines)
             }
 
             addImport("java.util.List", lines)
@@ -812,6 +813,17 @@ class TestSuiteWriter {
                     lines.indented {
                         lines.add(".jsonConfig(JsonConfig.jsonConfig().numberReturnType(JsonPathConfig.NumberReturnType.DOUBLE))")
                         lines.add(".redirect(redirectConfig().followRedirects(false))")
+                        if (config.dtoSupportedForPayload() && containsDtos) {
+                            lines.indented {
+                                lines.add(".objectMapperConfig(")
+                                lines.indented {
+                                    lines.add("ObjectMapperConfig.objectMapperConfig()")
+                                    val newQualifier = if (format.isJava()) "new" else ""
+                                    lines.add(".jackson2ObjectMapperFactory($newQualifier CustomControlCharMapperFactory())")
+                                }
+                                lines.add(")")
+                            }
+                        }
                     }
                     lines.appendSemicolon()
                 }