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Fixed old StrictNullChecks to throw exceptions similar to those thrown by new StrictNullChecks #1020

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Merged
merged 3 commits into from
Jul 12, 2025
+36 −30
Merged

Fixed old StrictNullChecks to throw exceptions similar to those thrown by new StrictNullChecks #1020

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3da5530
Fixed to throw exceptions similar to thrown by the new StrictNullChecks
k163377 Jul 12, 2025
4eb5562
Fix test
k163377 Jul 12, 2025
14cc112
Update release notes wrt #1020
k163377 Jul 12, 2025
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1 change: 1 addition & 0 deletions release-notes/CREDITS-2.x
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Expand Up @@ -18,6 +18,7 @@ Contributors:
# 2.20.0 (not yet released)

WrongWrong (@k163377)
* #1020: Fixed old StrictNullChecks to throw exceptions similar to those thrown by new StrictNullChecks
* #1018: Use MethodHandle in processing related to value class
* #969: Cleanup of deprecated contents
* #967: Update settings for 2.20
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3 changes: 3 additions & 0 deletions release-notes/VERSION-2.x
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Expand Up @@ -17,6 +17,9 @@ Co-maintainers:
------------------------------------------------------------------------

2.20.0 (not yet released)
#1020: Exceptions thrown by the old StrictNullChecks are now the similar to the new StrictNullChecks.
This means that the old StrictNullChecks will no longer throw MissingKotlinParameterException.
See PR for what is thrown and how error messages change.
#1018: Improved handling of `value class` has improved performance for both serialization and deserialization.
In particular, for serialization, proper caching has improved throughput by a factor of 2 or more in the general cases.
Also, replacing function execution by reflection with `MethodHandle` improved throughput by several percent for both serialization and deserialization.
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48 changes: 25 additions & 23 deletions src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinValueInstantiator.kt
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Expand Up @@ -11,6 +11,7 @@ import com.fasterxml.jackson.databind.deser.ValueInstantiator
import com.fasterxml.jackson.databind.deser.ValueInstantiators
import com.fasterxml.jackson.databind.deser.impl.PropertyValueBuffer
import com.fasterxml.jackson.databind.deser.std.StdValueInstantiator
import com.fasterxml.jackson.databind.exc.InvalidNullException
import java.lang.reflect.TypeVariable
import kotlin.reflect.KType
import kotlin.reflect.KTypeProjection
Expand Down Expand Up @@ -103,31 +104,32 @@ internal class KotlinValueInstantiator(
} else if (strictNullChecks) {
val arguments = paramType.arguments

var paramTypeStr: String? = null
var itemType: KType? = null

if (propType.isCollectionLikeType && arguments.markedNonNullAt(0) && (paramVal as Collection<*>).any { it == null }) {
paramTypeStr = "collection"
itemType = arguments[0].type
}

if (propType.isMapLikeType && arguments.markedNonNullAt(1) && (paramVal as Map<*, *>).any { it.value == null }) {
paramTypeStr = "map"
itemType = arguments[1].type
}

if (propType.isArrayType && arguments.markedNonNullAt(0) && (paramVal as Array<*>).any { it == null }) {
paramTypeStr = "array"
itemType = arguments[0].type
// To make the behavior the same as deserialization of each element using NullsFailProvider,
// first wrapWithPath with paramVal and key.
val ex = when {
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Copilot AI Jul 12, 2025

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[nitpick] The when block that builds InvalidNullException contains repeated patterns for collection and array cases. Consider extracting a helper function to handle index-based null checks and exception wrapping to reduce duplication and improve readability.

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propType.isCollectionLikeType && arguments.markedNonNullAt(0) -> {
(paramVal as Collection<*>).indexOf(null).takeIf { it >= 0 }?.let {
InvalidNullException.from(ctxt, jsonProp.fullName, jsonProp.type)
.wrapWithPath(paramVal, it)
}
}
propType.isMapLikeType && arguments.markedNonNullAt(1) -> {
(paramVal as Map<*, *>).entries.find { (_, v) -> v == null }?.let { (k, _) ->
InvalidNullException.from(ctxt, jsonProp.fullName, jsonProp.type)
.wrapWithPath(paramVal, k.toString())
}
}
propType.isArrayType && arguments.markedNonNullAt(0) -> {
(paramVal as Array<*>).indexOf(null).takeIf { it >= 0 }?.let {
InvalidNullException.from(ctxt, jsonProp.fullName, jsonProp.type)
.wrapWithPath(paramVal, it)
}
}
else -> null
}

if (paramTypeStr != null && itemType != null) {
throw MissingKotlinParameterException(
parameter = paramDef,
processor = ctxt.parser,
msg = "Instantiation of $itemType $paramType failed for JSON property ${jsonProp.name} due to null value in a $paramType that does not allow null values"
).wrapWithPath(this.valueClass, jsonProp.name)
}
// Then, wrapWithPath with this property.
ex?.let { throw it.wrapWithPath(this.valueClass, jsonProp.name) }
}

bucket[paramDef] = paramVal
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14 changes: 7 additions & 7 deletions src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/StrictNullChecksTestOld.kt
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@@ -1,7 +1,7 @@
package com.fasterxml.jackson.module.kotlin.test

import com.fasterxml.jackson.databind.exc.InvalidNullException
import com.fasterxml.jackson.module.kotlin.KotlinFeature
import com.fasterxml.jackson.module.kotlin.MissingKotlinParameterException
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
import com.fasterxml.jackson.module.kotlin.readValue
import org.junit.jupiter.api.Assertions.assertArrayEquals
Expand Down Expand Up @@ -32,7 +32,7 @@ class StrictNullChecksTestOld {

@Test
fun testListOfInt() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{"samples":[1, null]}"""
mapper.readValue<ClassWithListOfInt>(json)
}
Expand Down Expand Up @@ -62,7 +62,7 @@ class StrictNullChecksTestOld {

@Test
fun testArrayOfInt() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{"samples":[1, null]}"""
mapper.readValue<ClassWithArrayOfInt>(json)
}
Expand Down Expand Up @@ -92,7 +92,7 @@ class StrictNullChecksTestOld {

@Test
fun testMapOfStringToIntWithNullValue() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{ "samples": { "key": null } }"""
mapper.readValue<ClassWithMapOfStringToInt>(json)
}
Expand Down Expand Up @@ -121,7 +121,7 @@ class StrictNullChecksTestOld {
@Disabled // this is a hard problem to solve and is currently not addressed
@Test
fun testListOfGenericWithNullValue() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{"samples":[1, null]}"""
mapper.readValue<TestClass<List<Int>>>(json)
}
Expand All @@ -137,7 +137,7 @@ class StrictNullChecksTestOld {
@Disabled // this is a hard problem to solve and is currently not addressed
@Test
fun testMapOfGenericWithNullValue() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{ "samples": { "key": null } }"""
mapper.readValue<TestClass<Map<String, Int>>>(json)
}
Expand All @@ -153,7 +153,7 @@ class StrictNullChecksTestOld {
@Disabled // this is a hard problem to solve and is currently not addressed
@Test
fun testArrayOfGenericWithNullValue() {
assertThrows<MissingKotlinParameterException> {
assertThrows<InvalidNullException> {
val json = """{"samples":[1, null]}"""
mapper.readValue<TestClass<Array<Int>>>(json)
}
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