json patch dto conversion

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

@@ -23,6 +23,7 @@ import org.evomaster.core.search.gene.numeric.IntegerGene
 import org.evomaster.core.search.gene.numeric.LongGene
 import org.evomaster.core.search.gene.placeholder.CycleObjectGene
 import org.evomaster.core.search.gene.jsonpatch.JsonPatchDocumentGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchPathValueGene
 import org.evomaster.core.search.gene.regex.RegexGene
 import org.evomaster.core.search.gene.string.Base64StringGene
 import org.evomaster.core.search.gene.string.StringGene
@@ -119,18 +120,36 @@ class DtoWriter(
             gene is ObjectGene -> calculateDtoFromObject(gene, actionName)
             gene is ArrayGene<*> -> calculateDtoFromArray(gene, actionName)
             gene is FixedMapGene<*, *> -> calculateDtoFromFixedMapGene(gene, actionName)
-            // TODO: a JsonPatchDocumentGene is currently skipped from DTO collection. Once we decide
-            //  how a JSON Patch document should be rendered when a test case is written (it is not a
-            //  regular object/array DTO but an RFC 6902 array of operations), this should build and
-            //  emit the corresponding DTO instead of returning.
-            gene is JsonPatchDocumentGene -> return
+            gene is JsonPatchDocumentGene -> calculateDtoFromJsonPatch(gene)
             isPrimitiveGene(gene) -> return
             else -> {
                 throw IllegalStateException("Gene $gene is not supported for DTO payloads for action: $actionName")
             }
         }
     }
 
+    // Registers the shared JsonPatchOperation DTO and collects nested DTOs for object/array values.
+    private fun calculateDtoFromJsonPatch(gene: JsonPatchDocumentGene) {
+        val dtoName = GeneToDto.JSON_PATCH_OPERATION_DTO
+        val dtoClass = dtoCollector.computeIfAbsent(dtoName) { DtoClass(it) }
+        dtoClass.addField(GeneToDto.FIELD_OP, DtoField(GeneToDto.FIELD_OP, "String"))
+        dtoClass.addField(GeneToDto.FIELD_PATH, DtoField(GeneToDto.FIELD_PATH, "String"))
+        dtoClass.addField(GeneToDto.FIELD_FROM, DtoField(GeneToDto.FIELD_FROM, "String"))
+        dtoClass.addField(GeneToDto.FIELD_VALUE, DtoField(GeneToDto.FIELD_VALUE, anyType()))
+        dtoCollector[dtoName] = dtoClass
+
+        gene.operations.filterIsInstance<JsonPatchPathValueGene>().forEach { operation ->
+            when (val valueGene = operation.pathValueChoice.activeGene().second.getLeafGene()) {
+                is ObjectGene -> calculateDtoFromObject(valueGene, GeneToDto.FIELD_VALUE)
+                is ArrayGene<*> -> calculateDtoFromArray(valueGene, GeneToDto.FIELD_VALUE)
+            }
+        }
+    }
+
+    private fun anyType(): String {
+        return if (outputFormat.isJava()) "Object" else "Any"
+    }
+
     private fun calculateDtoFromFixedMapGene(gene: FixedMapGene<*, *>, actionName: String) {
         val dtoName = TestWriterUtils.safeVariableName(actionName)
         val dtoClass = dtoCollector.computeIfAbsent(dtoName) { DtoClass(dtoName) }

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

@@ -12,6 +12,11 @@ import org.evomaster.core.search.gene.collection.PairGene
 import org.evomaster.core.search.gene.datetime.DateGene
 import org.evomaster.core.search.gene.datetime.DateTimeGene
 import org.evomaster.core.search.gene.datetime.TimeGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchDocumentGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchFromPathGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchOperationGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchPathOnlyGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchPathValueGene
 import org.evomaster.core.search.gene.numeric.DoubleGene
 import org.evomaster.core.search.gene.numeric.FloatGene
 import org.evomaster.core.search.gene.numeric.IntegerGene
@@ -36,6 +41,15 @@ class GeneToDto(
     val outputFormat: OutputFormat
 ) {
 
+    companion object {
+        // Shared DTO class name for all JSON Patch operations (RFC 6902).
+        const val JSON_PATCH_OPERATION_DTO = "JsonPatchOperation"
+        const val FIELD_OP = "op"
+        const val FIELD_PATH = "path"
+        const val FIELD_FROM = "from"
+        const val FIELD_VALUE = "value"
+    }
+
     private val log: Logger = LoggerFactory.getLogger(GeneToDto::class.java)
 
     private var dtoOutput: DtoOutput = if (outputFormat.isJava()) {
@@ -67,6 +81,7 @@ class GeneToDto(
             }
             is ChoiceGene<*> -> TestWriterUtils.safeVariableName(fallback)
             is FixedMapGene<*,*> -> TestWriterUtils.safeVariableName(fallback)
+            is JsonPatchDocumentGene -> JSON_PATCH_OPERATION_DTO
             else -> throw IllegalStateException("Gene $gene is not supported for DTO payloads for action: $fallback")
         }
     }
@@ -85,10 +100,84 @@ class GeneToDto(
             is ArrayGene<*> -> getArrayDtoCall(gene, dtoName, counters, null, capitalize)
             is ChoiceGene<*> -> getDtoCall(gene.activeGene(), dtoName, counters, capitalize)
             is FixedMapGene<*,*> -> getFixedMapGeneDtoCall(gene, dtoName, counters)
+            is JsonPatchDocumentGene -> getJsonPatchDtoCall(gene, counters)
             else -> throw RuntimeException("BUG: Gene $gene (with type ${this::class.java.simpleName}) should not be creating DTOs")
         }
     }
 
+    // Renders a JSON Patch document as a List<JsonPatchOperation>, one DTO per active operation.
+    private fun getJsonPatchDtoCall(gene: JsonPatchDocumentGene, counters: MutableList<Int>): DtoCall {
+        val listVarName = "list_${JSON_PATCH_OPERATION_DTO}_${counters.joinToString("_")}"
+        val result = mutableListOf<String>()
+        result.add(dtoOutput.getNewListStatement(JSON_PATCH_OPERATION_DTO, listVarName))
+
+        var operationCounter = 1
+        gene.operations.forEach { operation ->
+            val childCounter = mutableListOf<Int>().apply {
+                addAll(counters)
+                add(operationCounter++)
+            }
+            val operationCall = getJsonPatchOperationCall(operation, childCounter)
+            result.addAll(operationCall.objectCalls)
+            result.add(dtoOutput.getAddElementToListStatement(listVarName, operationCall.varName))
+        }
+
+        return DtoCall(listVarName, result)
+    }
+
+    // Renders a single RFC 6902 operation as a JsonPatchOperation DTO with only its relevant fields set.
+    private fun getJsonPatchOperationCall(operation: JsonPatchOperationGene, counters: MutableList<Int>): DtoCall {
+        val varName = "dto_${JSON_PATCH_OPERATION_DTO}_${counters.joinToString("_")}"
+        val result = mutableListOf<String>()
+        result.add(dtoOutput.getNewObjectStatement(JSON_PATCH_OPERATION_DTO, varName))
+        result.add(dtoOutput.getSetterStatement(varName, FIELD_OP, "\"${operation.operationName}\""))
+
+        when (operation) {
+            is JsonPatchPathOnlyGene -> {
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_PATH, renderLeafValue(operation.pathGene)))
+            }
+            is JsonPatchFromPathGene -> {
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_FROM, renderLeafValue(operation.fromGene)))
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_PATH, renderLeafValue(operation.pathGene)))
+            }
+            is JsonPatchPathValueGene -> {
+                val pair = operation.pathValueChoice.activeGene()
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_PATH, renderLeafValue(pair.first)))
+                setJsonPatchValue(varName, pair.second.getLeafGene(), counters, result)
+            }
+        }
+
+        return DtoCall(varName, result)
+    }
+
+    // Sets the "value" field: primitives are inlined as literals, objects/arrays delegate to DTO generation.
+    private fun setJsonPatchValue(
+        varName: String,
+        valueGene: Gene,
+        counters: MutableList<Int>,
+        result: MutableList<String>
+    ) {
+        when (valueGene) {
+            is ObjectGene -> {
+                val childCall = getDtoCall(valueGene, getDtoName(valueGene, FIELD_VALUE, true), counters, true)
+                result.addAll(childCall.objectCalls)
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_VALUE, childCall.varName))
+            }
+            is ArrayGene<*> -> {
+                val childCall = getArrayDtoCall(valueGene, getDtoName(valueGene, FIELD_VALUE, true), counters, FIELD_VALUE, true)
+                result.addAll(childCall.objectCalls)
+                result.add(dtoOutput.getSetterStatement(varName, FIELD_VALUE, childCall.varName))
+            }
+            else -> result.add(dtoOutput.getSetterStatement(varName, FIELD_VALUE, renderLeafValue(valueGene)))
+        }
+    }
+
+    // Returns the printable string representation of a gene's leaf value with its language-specific suffix.
+    private fun renderLeafValue(gene: Gene): String {
+        val leafGene = gene.getLeafGene()
+        return "${leafGene.getValueAsPrintableString(targetFormat = outputFormat)}${getValueSuffix(leafGene)}"
+    }
+
     private fun getObjectDtoCall(gene: ObjectGene, dtoName: String, counters: MutableList<Int>): DtoCall {
         val dtoVarName = "dto_${dtoName}_${counters.joinToString("_")}"
 

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

@@ -128,11 +128,13 @@ abstract class HttpWsTestCaseWriter : ApiTestCaseWriter() {
         val bodyParam = call.parameters.find { p -> p is BodyParam } as BodyParam?
         if (bodyParam != null && bodyParam.isJson() && payloadIsValidJson(bodyParam)) {
             val primaryGene = bodyParam.primaryGene()
-            if (primaryGene.getWrappedGene(JsonPatchDocumentGene::class.java) != null) {
-                return ""
+            val actionName = call.getName()
+            val jsonPatchGene = primaryGene.getWrappedGene(JsonPatchDocumentGene::class.java)
+            if (jsonPatchGene != null) {
+                // A JSON Patch document is rendered as a List<JsonPatchOperation> DTO (RFC 6902).
+                return generateDtoCall(jsonPatchGene, actionName, lines).varName
             }
             val choiceGene = primaryGene.getWrappedGene(ChoiceGene::class.java)
-            val actionName = call.getName()
             if (choiceGene != null) {
                 // We only generate DTOs for ChoiceGene objects that contain either an ObjectGene or ArrayGene in their
                 // genes. This check is necessary since when using `example` and `default` entries,

core/src/test/kotlin/org/evomaster/core/output/TestCaseWriterTest.kt

@@ -27,8 +27,11 @@ import org.evomaster.core.search.gene.UUIDGene
 import org.evomaster.core.search.gene.collection.EnumGene
 import org.evomaster.core.search.gene.numeric.IntegerGene
 import org.evomaster.core.search.gene.string.StringGene
+import org.evomaster.core.output.dto.GeneToDto
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchDocumentGene
 import org.evomaster.core.search.gene.utils.GeneUtils
 import org.evomaster.core.search.gene.wrapper.OptionalGene
+import org.evomaster.core.search.service.Randomness
 import org.evomaster.core.sql.schema.TableId
 import org.junit.jupiter.api.Assertions.*
 import org.junit.jupiter.api.Test
@@ -1641,6 +1644,40 @@ public void test() throws Exception {
         }
     }
 
+    @Test
+    fun testJsonPatchBodyRenderedAsDto() {
+        val format = OutputFormat.KOTLIN_JUNIT_5
+        val baseUrlOfSut = "baseUrlOfSut"
+
+        val schema = ObjectGene("body", listOf(StringGene("name"), IntegerGene("age")))
+        val typeGene = EnumGene("contentType", listOf("application/json-patch+json")).apply { index = 0 }
+        val bodyParam = BodyParam(gene = JsonPatchDocumentGene("patch", schema), typeGene = typeGene)
+
+        val action = RestCallAction("1", HttpVerb.PATCH, RestPath("/items/1"), mutableListOf(bodyParam))
+        val individual = RestIndividual(mutableListOf(action), SampleType.RANDOM)
+        TestUtils.doInitializeIndividualForTesting(individual, Randomness().apply { updateSeed(42L) })
+
+        val fitnessVal = FitnessValue(0.0)
+        val result = RestCallResult(action.getLocalId()).apply { setStatusCode(200) }
+        val ei = EvaluatedIndividual(fitnessVal, individual, listOf(result))
+
+        val config = getConfig(format)
+        config.dtoForRequestPayload = true
+        config.problemType = EMConfig.ProblemType.REST
+
+        val test = TestCase(test = ei, name = "test")
+        val writer = RestTestCaseWriter(config, PartialOracles())
+        val output = writer.convertToCompilableTestCode(test, baseUrlOfSut).toString()
+
+        // The JSON Patch body must be rendered as a DTO list, not as a raw JSON string.
+        assertTrue(output.contains("list_${GeneToDto.JSON_PATCH_OPERATION_DTO}_"),
+            "Expected DTO list variable in generated output")
+        assertTrue(output.contains(".body(list_${GeneToDto.JSON_PATCH_OPERATION_DTO}_"),
+            "Expected DTO variable passed as body argument")
+        assertFalse(output.contains("{\"op\":"),
+            "Body must not contain raw JSON string representation of a patch operation")
+    }
+
     @Test
     fun testInActiveBodyParamInTest(){
         val stringGene = StringGene("stringGene")

core/src/test/kotlin/org/evomaster/core/output/dto/DtoWriterJsonPatchTest.kt

@@ -0,0 +1,107 @@
+package org.evomaster.core.output.dto
+
+import org.evomaster.core.TestUtils
+import org.evomaster.core.output.OutputFormat
+import org.evomaster.core.output.Termination
+import org.evomaster.core.output.naming.RestActionTestCaseUtils.getEvaluatedIndividualWith
+import org.evomaster.core.output.naming.RestActionTestCaseUtils.getRestCallAction
+import org.evomaster.core.problem.api.param.Param
+import org.evomaster.core.problem.enterprise.SampleType
+import org.evomaster.core.problem.rest.data.HttpVerb
+import org.evomaster.core.problem.rest.data.RestCallResult
+import org.evomaster.core.problem.rest.data.RestIndividual
+import org.evomaster.core.problem.rest.param.BodyParam
+import org.evomaster.core.search.EvaluatedIndividual
+import org.evomaster.core.search.FitnessValue
+import org.evomaster.core.search.Solution
+import org.evomaster.core.search.gene.ObjectGene
+import org.evomaster.core.search.gene.collection.ArrayGene
+import org.evomaster.core.search.gene.collection.EnumGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchDocumentGene
+import org.evomaster.core.search.gene.jsonpatch.JsonPatchPathValueGene
+import org.evomaster.core.search.gene.numeric.IntegerGene
+import org.evomaster.core.search.gene.string.StringGene
+import org.evomaster.core.search.service.Randomness
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import java.nio.file.Paths
+import java.util.Collections.singletonList
+
+class DtoWriterJsonPatchTest {
+
+    private val outputTestSuitePath = Paths.get("./target/dto-writer-json-patch-test")
+    private val testPackage = "test.package"
+
+    private fun jsonPatchBodyParam(): Param {
+        val schema = ObjectGene("body", listOf(StringGene("name"), IntegerGene("age")))
+        val typeGene = EnumGene("contentType", listOf("application/json-patch+json")).apply { index = 0 }
+        return BodyParam(gene = JsonPatchDocumentGene("patch", schema), typeGene = typeGene)
+    }
+
+    private fun jsonPatchSolution(): Solution<*> {
+        val action = getRestCallAction("/items/{id}", HttpVerb.PATCH, mutableListOf(jsonPatchBodyParam()))
+        val eIndividual = getEvaluatedIndividualWith(action)
+        return Solution(singletonList(eIndividual), "", "", Termination.NONE, emptyList(), emptyList())
+    }
+
+    @Test
+    fun collectsJsonPatchOperationDtoWithAllFields() {
+        val dtoWriter = DtoWriter(OutputFormat.KOTLIN_JUNIT_5)
+        dtoWriter.write(outputTestSuitePath, testPackage, jsonPatchSolution())
+
+        val dtos = dtoWriter.getCollectedDtos()
+        val operationDto = dtos[GeneToDto.JSON_PATCH_OPERATION_DTO]
+        assertNotNull(operationDto, "Expected a ${GeneToDto.JSON_PATCH_OPERATION_DTO} DTO to be collected")
+
+        val fields = operationDto!!.fieldsMap
+        assertEquals(DtoField(GeneToDto.FIELD_OP, "String"), fields[GeneToDto.FIELD_OP])
+        assertEquals(DtoField(GeneToDto.FIELD_PATH, "String"), fields[GeneToDto.FIELD_PATH])
+        assertEquals(DtoField(GeneToDto.FIELD_FROM, "String"), fields[GeneToDto.FIELD_FROM])
+        // value is the generic object type since a JSON Patch value can be any JSON value
+        assertEquals(DtoField(GeneToDto.FIELD_VALUE, "Any"), fields[GeneToDto.FIELD_VALUE])
+    }
+
+    @Test
+    fun valueFieldIsObjectForJavaOutput() {
+        val dtoWriter = DtoWriter(OutputFormat.JAVA_JUNIT_5)
+        dtoWriter.write(outputTestSuitePath, testPackage, jsonPatchSolution())
+
+        val operationDto = dtoWriter.getCollectedDtos()[GeneToDto.JSON_PATCH_OPERATION_DTO]
+        assertNotNull(operationDto)
+        assertEquals(DtoField(GeneToDto.FIELD_VALUE, "Object"), operationDto!!.fieldsMap[GeneToDto.FIELD_VALUE])
+    }
+
+    @Test
+    fun collectsNestedObjectDtoWhenValueIsArrayOfObjects() {
+        // Schema where the only patchable field is an array of objects:
+        // every add/replace/test operation will have an ArrayGene<ObjectGene> as its value gene,
+        // so calculateDtoFromJsonPatch must visit calculateDtoFromArray for those operations.
+        val tagSchema = ObjectGene("Tag", listOf(StringGene("label")), refType = "Tag")
+        val schema = ObjectGene("body", listOf(ArrayGene("tags", tagSchema)))
+        val typeGene = EnumGene("contentType", listOf("application/json-patch+json")).apply { index = 0 }
+        val bodyParam = BodyParam(gene = JsonPatchDocumentGene("patch", schema), typeGene = typeGene)
+
+        val action = getRestCallAction("/items/{id}", HttpVerb.PATCH, mutableListOf(bodyParam))
+        val individual = RestIndividual(mutableListOf(action), SampleType.RANDOM)
+        TestUtils.doInitializeIndividualForTesting(individual, Randomness().apply { updateSeed(42L) })
+
+        val result = RestCallResult(action.getLocalId()).apply { setStatusCode(200) }
+        val ei = EvaluatedIndividual<RestIndividual>(FitnessValue(0.0), individual, listOf(result))
+        val solution = Solution(singletonList(ei), "", "", Termination.NONE, emptyList(), emptyList())
+
+        val dtoWriter = DtoWriter(OutputFormat.KOTLIN_JUNIT_5)
+        dtoWriter.write(outputTestSuitePath, testPackage, solution)
+        val dtos = dtoWriter.getCollectedDtos()
+
+        assertNotNull(dtos[GeneToDto.JSON_PATCH_OPERATION_DTO])
+
+        val patchGene = bodyParam.primaryGene() as JsonPatchDocumentGene
+        val pathValueOps = patchGene.operations.filterIsInstance<JsonPatchPathValueGene>()
+        assertTrue(pathValueOps.isNotEmpty(), "Seed 42L must produce at least one add/replace/test operation")
+        // All add/replace/test operations carry an ArrayGene<ObjectGene> value in this schema;
+        // the nested Tag DTO must therefore be collected.
+        assertNotNull(dtos["Tag"], "Nested Tag DTO must be collected for operations with array-of-objects value")
+    }
+}