Unwrap NestedServletException in codegen #2586 (#2587)

* Make tests throwing `NestedServletException` fail, print cause stacktrace

* Make exception collection only skip exceptions inside `assertThrows`

Author: IlyaMuravjov

utbot-framework-api/src/main/kotlin/org/utbot/framework/plugin/api/util/SpringModelUtils.kt

@@ -173,6 +173,12 @@ object SpringModelUtils {
     private val objectMapperClassId = ClassId("com.fasterxml.jackson.databind.ObjectMapper")
     private val cookieClassId = ClassId("javax.servlet.http.Cookie")
 
+    // as of Spring 6.0 `NestedServletException` is deprecated in favor of standard `ServletException` nesting
+    val nestedServletExceptionClassIds = listOf(
+        ClassId("org.springframework.web.util.NestedServletException"),
+        ClassId("jakarta.servlet.ServletException")
+    )
+
     private val requestAttributesMethodId = MethodId(
         classId = mockHttpServletRequestBuilderClassId,
         name = "requestAttr",

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/domain/context/CgContext.kt

@@ -296,26 +296,8 @@ interface CgContextOwner {
         return block()
     }
 
-    fun addExceptionIfNeeded(exception: ClassId) {
-        if (exception !is BuiltinClassId) {
-            require(exception isSubtypeOf Throwable::class.id) {
-                "Class $exception which is not a Throwable was passed"
-            }
-
-            val isUnchecked = !exception.jClass.isCheckedException
-            val alreadyAdded =
-                collectedExceptions.any { existingException -> exception isSubtypeOf existingException }
-
-            if (isUnchecked || alreadyAdded) return
-
-            collectedExceptions
-                .removeIf { existingException -> existingException isSubtypeOf exception }
-        }
-
-        if (collectedExceptions.add(exception)) {
-            importIfNeeded(exception)
-        }
-    }
+    fun addExceptionIfNeeded(exception: ClassId)
+    fun <T> runWithoutCollectingExceptions(block: () -> T): T
 
     fun createGetClassExpression(id: ClassId, codegenLanguage: CodegenLanguage): CgGetClass =
         when (codegenLanguage) {
@@ -624,6 +606,40 @@ class CgContext(
         mockFrameworkUsed = false
     }
 
+    // number of times collection of exceptions was suspended
+    private var exceptionCollectionSuspensionDepth = 0
+
+    override fun <T> runWithoutCollectingExceptions(block: () -> T): T {
+        exceptionCollectionSuspensionDepth++
+        return try {
+            block()
+        } finally {
+            exceptionCollectionSuspensionDepth--
+        }
+    }
+
+    override fun addExceptionIfNeeded(exception: ClassId) {
+        if (exceptionCollectionSuspensionDepth > 0) return
+        if (exception !is BuiltinClassId) {
+            require(exception isSubtypeOf Throwable::class.id) {
+                "Class $exception which is not a Throwable was passed"
+            }
+
+            val isUnchecked = !exception.jClass.isCheckedException
+            val alreadyAdded =
+                collectedExceptions.any { existingException -> exception isSubtypeOf existingException }
+
+            if (isUnchecked || alreadyAdded) return
+
+            collectedExceptions
+                .removeIf { existingException -> existingException isSubtypeOf exception }
+        }
+
+        if (collectedExceptions.add(exception)) {
+            importIfNeeded(exception)
+        }
+    }
+
     override var currentTestSetId: Int = -1
 
     override var currentExecutionId: Int = -1

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/services/access/CgCallableAccessManager.kt

@@ -1,8 +1,6 @@
 package org.utbot.framework.codegen.services.access
 
 import kotlinx.collections.immutable.PersistentList
-import org.utbot.framework.codegen.domain.Junit5
-import org.utbot.framework.codegen.domain.TestNg
 import org.utbot.framework.codegen.domain.builtin.any
 import org.utbot.framework.codegen.domain.builtin.anyOfClass
 import org.utbot.framework.codegen.domain.builtin.getMethodId
@@ -47,7 +45,6 @@ import org.utbot.framework.plugin.api.ConstructorId
 import org.utbot.framework.plugin.api.ExecutableId
 import org.utbot.framework.plugin.api.FieldId
 import org.utbot.framework.plugin.api.MethodId
-import org.utbot.framework.plugin.api.UtExplicitlyThrownException
 import org.utbot.framework.plugin.api.util.exceptions
 import org.utbot.framework.plugin.api.util.extensionReceiverParameterIndex
 import org.utbot.framework.plugin.api.util.humanReadableName
@@ -160,16 +157,6 @@ class CgCallableAccessManagerImpl(val context: CgContext) : CgCallableAccessMana
             addExceptionIfNeeded(Throwable::class.id)
         }
 
-        val methodIsToCallAndThrowsExplicitly = methodId == currentExecutableToCall
-                && currentExecution?.result is UtExplicitlyThrownException
-        val frameworkSupportsAssertThrows = testFramework == Junit5 || testFramework == TestNg
-
-        //If explicit exception is wrapped with assertThrows,
-        // no "throws" in test method signature is required.
-        if (methodIsToCallAndThrowsExplicitly && frameworkSupportsAssertThrows) {
-            return
-        }
-
         methodId.method.exceptionTypes.forEach { addExceptionIfNeeded(it.id) }
     }
 

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/services/framework/TestFrameworkManager.kt

@@ -286,7 +286,9 @@ internal class TestNgManager(context: CgContext) : TestFrameworkManager(context)
 
     override fun expectException(exception: ClassId, block: () -> Unit) {
         require(testFramework is TestNg) { "According to settings, TestNg was expected, but got: $testFramework" }
-        val lambda = statementConstructor.lambda(testFramework.throwingRunnableClassId) { block() }
+        val lambda = statementConstructor.lambda(testFramework.throwingRunnableClassId) {
+            runWithoutCollectingExceptions(block)
+        }
         +assertions[assertThrows](exception.toExceptionClass(), lambda)
     }
 
@@ -474,7 +476,9 @@ internal class Junit5Manager(context: CgContext) : TestFrameworkManager(context)
 
     override fun expectException(exception: ClassId, block: () -> Unit) {
         require(testFramework is Junit5) { "According to settings, JUnit5 was expected, but got: $testFramework" }
-        val lambda = statementConstructor.lambda(testFramework.executableClassId) { block() }
+        val lambda = statementConstructor.lambda(testFramework.executableClassId) {
+            runWithoutCollectingExceptions(block)
+        }
         +assertions[assertThrows](exception.toExceptionClass(), lambda)
     }
 

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgMethodConstructor.kt

@@ -471,6 +471,18 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
             .map { it.escapeControlChars() }
             .toMutableList()
 
+        +CgMultilineComment(warningLine + collectNeededStackTraceLines(
+            exception,
+            executableToStartCollectingFrom = currentExecutableToCall!!
+        ))
+    }
+
+    protected open fun collectNeededStackTraceLines(
+        exception: Throwable,
+        executableToStartCollectingFrom: ExecutableId
+    ): List<String> {
+        val executableName = "${executableToStartCollectingFrom.classId.name}.${executableToStartCollectingFrom.name}"
+
         val neededStackTraceLines = mutableListOf<String>()
         var executableCallFound = false
         exception.stackTrace.reversed().forEach { stackTraceElement ->
@@ -485,7 +497,7 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
         if (!executableCallFound)
             logger.warn(exception) { "Failed to find executable call in stack trace" }
 
-        +CgMultilineComment(warningLine + neededStackTraceLines.reversed())
+        return neededStackTraceLines.reversed()
     }
 
     protected fun writeWarningAboutCrash() {
@@ -1819,6 +1831,9 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
         currentExecution = execution
         determineExecutionType()
         statesCache = EnvironmentFieldStateCache.emptyCacheFor(execution)
+//        modelToUsageCountInMethod = countUsages(ignoreAssembleOrigin = true) { counter ->
+//            execution.mapAllModels(counter)
+//        }
         return try {
             block()
         } finally {

utbot-spring-framework/src/main/kotlin/org/utbot/framework/codegen/generator/SpringCodeGenerator.kt

@@ -5,7 +5,9 @@ import org.utbot.framework.codegen.domain.models.CgMethodTestSet
 import org.utbot.framework.codegen.domain.models.builders.SimpleTestClassModelBuilder
 import org.utbot.framework.codegen.services.language.CgLanguageAssistant
 import org.utbot.framework.codegen.tree.CgCustomAssertConstructor
+import org.utbot.framework.codegen.tree.CgMethodConstructor
 import org.utbot.framework.codegen.tree.CgSpringIntegrationTestClassConstructor
+import org.utbot.framework.codegen.tree.CgSpringMethodConstructor
 import org.utbot.framework.codegen.tree.CgSpringUnitTestClassConstructor
 import org.utbot.framework.codegen.tree.CgSpringVariableConstructor
 import org.utbot.framework.codegen.tree.CgVariableConstructor
@@ -30,6 +32,9 @@ class SpringCodeGenerator(
                 // TODO decorate original `params.cgLanguageAssistant.getVariableConstructorBy(context)`
                 CgSpringVariableConstructor(context)
 
+            override fun getMethodConstructorBy(context: CgContext): CgMethodConstructor =
+                CgSpringMethodConstructor(context)
+
             override fun getCustomAssertConstructorBy(context: CgContext): CgCustomAssertConstructor =
                 params.cgLanguageAssistant.getCustomAssertConstructorBy(context)
                     .withCustomAssertForMockMvcResultActions()

utbot-spring-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgSpringMethodConstructor.kt

@@ -0,0 +1,27 @@
+package org.utbot.framework.codegen.tree
+
+import org.utbot.framework.codegen.domain.context.CgContext
+import org.utbot.framework.plugin.api.ExecutableId
+import org.utbot.framework.plugin.api.UtExecution
+import org.utbot.framework.plugin.api.util.SpringModelUtils.mockMvcPerformMethodId
+import org.utbot.framework.plugin.api.util.SpringModelUtils.nestedServletExceptionClassIds
+import org.utbot.framework.plugin.api.util.id
+
+class CgSpringMethodConstructor(context: CgContext) : CgMethodConstructor(context) {
+    override fun shouldTestPassWithException(execution: UtExecution, exception: Throwable): Boolean =
+        !isNestedServletException(exception) && super.shouldTestPassWithException(execution, exception)
+
+    override fun collectNeededStackTraceLines(
+        exception: Throwable,
+        executableToStartCollectingFrom: ExecutableId
+    ): List<String> =
+        // `mockMvc.perform` wraps exceptions from user code into NestedServletException, so we unwrap them back
+        exception.takeIf {
+            executableToStartCollectingFrom == mockMvcPerformMethodId && isNestedServletException(it)
+        }?.cause?.let { cause ->
+            super.collectNeededStackTraceLines(cause, currentExecutableUnderTest!!)
+        } ?: super.collectNeededStackTraceLines(exception, executableToStartCollectingFrom)
+
+    private fun isNestedServletException(exception: Throwable): Boolean =
+        exception::class.java.id in nestedServletExceptionClassIds
+}