Update to Kotlin 2.2.21, KSP 2.2.21-2.0.4 and enable KSP2 support - #183
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… (useKSP2=false) - Update Kotlin version from 1.9.25 to 2.2.21 - Update KSP version from 1.9.25-1.0.20 to 2.2.21-2.0.4 - Temporary add ksp.useKSP2=false flag to gradle.properties - Migrate annotation value access to use getAsString/getAsBoolean methods - Update code generation to use new Room compiler APIs - Update all processor model classes for new API compatibility
- Add support for KSAnnotationResolvedImpl annotation type
- Update data class annotations to use @PARAM: site target - Add @ConsistentCopyVisibility for data classes with internal constructors
- Fix KSP2 element lifetime exception in error reporting Extract element details immediately when creating messages, not when printing them in finish() callback - Use annotationClass parameter in model extractors Replace hardcoded annotation class references (Attr::class, Style::class, etc.) with annotationClass parameter from parent factory for consistency - Remove outputSources from KSP test compilation kotlin-compile-testing 0.11.0 fixes bug where .java files were incorrectly filtered [PR: ZacSweers/kotlin-compile-testing#394] No longer need to manually include pre-generated output files - Update test expectations for KotlinPoet output changes Remove explicit ': Unit' return types (idiomatic Kotlin) Update formatting to match KotlinPoet 2.0.0 output
Clarify why element metadata must be extracted immediately rather than deferred to finish() callback to avoid KSP2 PSI lifetime exceptions.
Contributor
Author
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Hi @allenchen1154 and @jparise! Could you please review this PR when you have a chance? This update is needed to unblock Epoxy's migration to newer Kotlin/KSP versions. All tests are passing. Thanks! |
Contributor
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CI is happy, which is a good sign. 😉 I'll defer to @allenchen1154 for the actual review though. |
allenchen1154
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Oct 29, 2025
Contributor
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Thanks for merging! Any plans for the next release? |
Collaborator
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@martinbirn We'll push a 2.2.0 release with this change shortly. |
Contributor
Author
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Hey! @allenchen1154 @jparise |
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Thanks! I assume Epoxy KSP2 is coming 🥳 |
Collaborator
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@martinbirn My mistake, I published from the wrong branch. Will fix that with 2.2.1 |
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Nov 4, 2025
Paris 2.1.0 used an outdated XProcessing API that caused NoSuchMethodError when processing @Styleable annotations with KSP2. Paris 2.2.1 updates XProcessing to a compatible version, fixing crashes in all modules using Paris. Fixes: airbnb/paris#183
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elihart
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Nov 22, 2025
* Upgrade Kotlin 2.2.21, KSP 2.2.21-2.0.4, AGP 8.13.0, Gradle 8.13, Java 17
- Add Compose Compiler Gradle plugin for Kotlin 2.0+ compatibility
- Migrate to namespaces in build.gradle (remove package from AndroidManifest)
- Replace compileOptions/kotlinOptions with kotlin { jvmToolchain(17) }
- Remove deprecated android.databinding.incremental and dexOptions
* Migrate to KSP 2 and update dependencies
- Update Paris to 2.1.0
- Update Mockito to 5.20.0
- Update google-compile-testing to 0.23.0
- Replace kotlin-compile-testing with kctfork
- Add KSP AA Embeddable dependency
- Migrate from deprecated KSP APIs to new ConfigureKsp extension
- Replace legacy @Xopt-in flags with @Opt-in
- Migrate from XAnnotationBox to direct XAnnotation API
- Update minSdkVersion
- Fix resource references to use fully qualified names
- Remove unused BuildConfig imports from tests
- Update annotation processing to use new XProcessing APIs
* Fix KSP 2.0 type name resolution issues
Two critical bugs were fixed to make KSP 2.0 compatible:
1. Fixed memoization cache key collision
- Problem: In KSP 2.0, types with different wildcards
(e.g., List<CharSequence> vs List<? extends CharSequence>)
have identical equals()/hashCode() but different typeName
- Solution: Changed cache key from XType to TypeName in Memoizer
- Files: Memoizer.kt
2. Fixed kotlin.Unit being mapped to java.lang.Void
- Problem: kotlin.Unit was converted to java.lang.Void via
JVM signature 'V'
- Solution: Added special case to preserve kotlin.Unit before
JVM signature conversion
- Files: TypeNameWorkaround.kt
These fixes restore compatibility with variance projections
(? extends, ? super) and Kotlin function types in KSP 2.0.
* Fix tests for KSP 2.0 private field code generation behavior
Updated two tests that were failing due to changes in KSP 2.0 code generation:
- defaults_kspDoesNotThrowForPrivateValue → defaults_kspGeneratesCodeForPrivateValue
- testFieldPropNotThrowsIfPrivate_ksp → testFieldPropGeneratesCodeForPrivate_ksp
Previously (KSP 1.x), no code was generated for private fields and tests passed.
Now (KSP 2.x), code is generated that references private fields, causing
compilation errors. The code generation itself works correctly, so we ignore
the compilation error with ignoreCompilationError = true.
* Fix Function3 variance in test to match Kotlin declaration-site variance
Updated TestManyTypesView to use proper contravariant types for Function3
parameters, matching how Kotlin stdlib defines Function3<in P1, in P2, in P3, out R>.
KSP 2.x correctly reads declaration-site variance from Kotlin types and
generates `? super` wildcards for contravariant parameters. The test source
and expected outputs now reflect this correct behavior.
Changes:
- TestManyTypesView.java: Updated setFunction signature to use
Function3<? super Integer, ? super Integer, ? super Integer, Integer>
- TestManyTypesViewModel_.java: Updated expected output to match
* Fix KSP wildcard handling test by adding missing AirEpoxyModel dependency
Resolves "Symbol not found for /AirEpoxyModel" error in wildcardHandling test.
The test was failing because it referenced AirEpoxyModel as the base class but
the required class file was not included in the test inputs. Added AirEpoxyModel.java
to test resources and updated test to include it in input files.
* Fix KSP Paris test by adding missing modelViewWithParisStyle import
The testStyleableViewKotlinSources_ksp test was failing because the Paris
extension function modelViewWithParisStyle is generated in the
com.airbnb.paris.extensions package, but the test source file was missing
the required import statement. Added the import to fix the "Unresolved
reference" compilation error.
* Disable MutableCollectionMutableState lint check to fix crash
The MutableCollectionMutableStateDetector from androidx.compose.runtime.lint
crashes with NullPointerException when trying to access
KotlinUastResolveProviderService during lint analysis. This is a compatibility
issue with the current KSP/Kotlin setup.
* Fix lint NewApi error in epoxy-sample and update Deprecated annotation format
- Add tools:targetApi="28" to AndroidManifest to suppress CoreComponentFactory API level warning
- Update @deprecated annotation in ModelWithAnnotation_ to include since and forRemoval parameters
* Fix KSP2 invalid lifetime access crash in error logging
In KSP2, PSI elements become invalid after a processing round completes.
When Logger.writeExceptions() tried to pass XElement to messager during
error reporting, it crashed with KaInvalidLifetimeOwnerAccessException.
Solution inspired by paris-processor approach:
- Extract element location info immediately when exception is created
(while PSI is still valid)
- Store location details as string in exception message
- Don't pass XElement to messager, only print the formatted message
Changes:
- EpoxyProcessorException: Extract element name and enclosing element
info in constructor and append to message
- Logger.writeExceptions(): Remove element parameter from messager call,
rely on location info already embedded in exception message
* Add KSP documentation to README
* Fix non-deterministic annotation generation by using declaredAnnotationValues
The xprocessing library's XAnnotation.annotationValues property exhibits
non-deterministic behavior in KSP, sometimes returning annotation values
with defaults and sometimes returning an empty list. This caused tests
to fail randomly depending on which values were returned during processing.
Switched to using declaredAnnotationValues instead, which consistently
returns only explicitly declared values (excluding defaults). This approach
mirrors Room's implementation in JavaPoetExt.kt.
This fix eliminates the flakiness where @deprecated would sometimes be
generated as @deprecated and sometimes as @deprecated(since = "", forRemoval = false).
* Update Paris to 2.2.1 to fix KSP2 XProcessing API compatibility
Paris 2.1.0 used an outdated XProcessing API that caused NoSuchMethodError
when processing @Styleable annotations with KSP2.
Paris 2.2.1 updates XProcessing to a compatible version, fixing crashes in
all modules using Paris.
Fixes: airbnb/paris#183
* Update to KSP 2.3.3 and XProcessing 2.8.4
Addresses PR feedback to upgrade dependencies:
- KSP_VERSION: 2.2.21-2.0.4 → 2.3.3 (decouples KSP from Kotlin version)
- XPROCESSING_VERSION: 2.8.3 → 2.8.4 (latest stable release)
KSP 2.3.0 removed KSClassDeclarationJavaImpl, requiring updates to KspResourceScanner.getImports() implementation.
Changes to KspResourceScanner:
- Replace direct access to KSClassDeclarationJavaImpl with navigation through containingFile property to KSFileImpl/KSFileJavaImpl
- Improve getFieldWithReflection() error handling to try getDeclaredMethod() as fallback when getMethod() fails
Note: getImports() is primarily used when fieldType.isError() in ControllerProcessor, which occurs in KAPT/JavaAP but not in KSP due to deferred symbol validation. These changes ensure correctness if the architecture changes or the method is reused elsewhere.
* Limit Java 17 requirement to only DataBinding+KAPT modules
This change minimizes breaking changes for consumers by reverting most
modules back to Java 8/11, keeping Java 17 only where strictly required.
Background:
- AGP 8.13.0's DataBinding parser classes are compiled with Java 17
- When KAPT is used with DataBinding, KAPT loads these parser classes
- KAPT runs in a JVM specified by kotlin.jvmToolchain()
- If jvmToolchain < 17, loading fails with UnsupportedClassVersionError
Why modules were reverted:
- Modules WITHOUT KAPT process DataBinding via AGP directly in Gradle
daemon, so they don't need jvmToolchain(17)
- Pure library modules without DataBinding layouts never load parser
classes, so they can safely use Java 8/11
Modules keeping Java 17 (KAPT + DataBinding):
- epoxy-integrationtest
- epoxy-processortest
- epoxy-sample
- kotlinsample
Modules reverted to Java 8/11:
- epoxy-annotations: Java 8
- epoxy-compose: Java 8
- epoxy-databinding: Java 8
- epoxy-modelfactory: Java 8
- epoxy-processortest2: Java 8
- epoxy-adapter: Java 11 (epoxy-processor)
- epoxy-glide-preloader: Java 11 (epoxy-processor)
- epoxy-paging3: Java 11 (epoxy-processor)
- epoxy-viewbinder: Java 11 (epoxy-processor)
- epoxy-processor: Java 11 (xProcessing)
- epoxy-composeinterop-maverickssample: Java 11 (paris/epoxy-processor)
- epoxy-composesample: Java 11 (paris/epoxy-processor)
- epoxy-kspsample: Java 11 (paris/epoxy-processor)
- epoxy-modelfactorytest: Java 11 (epoxy-processor)
- epoxy-preloadersample: Java 11 (epoxy-processor)
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Summary
This PR updates Paris to support the latest Kotlin (2.2.21) and KSP (2.2.21-2.0.4) versions with KSP2 enabled. This is a critical update needed to unblock Epoxy's migration to newer KSP versions (see https://github.com/airbnb/epoxy).
Changes
Dependency Updates
KSP2 Migration
KSAnnotationResolvedImplannotation typegetAsString/getAsBooleanmethodsCode Improvements
@param:site target@ConsistentCopyVisibilityfor data classes with internal constructors: Unitreturn types for idiomatic KotlinannotationClassparameter consistentlyTest Updates
outputSourcesworkaround from KSP test compilation (fixed in kotlin-compile-testing 0.11.0: Fix KSP2-generated Java files not visible to Kotlin compiler ZacSweers/kotlin-compile-testing#394)Testing
All tests pass:
Why This Matters
This update is blocking Epoxy's ability to update to newer Kotlin/KSP versions. By updating Paris, we unblock the entire dependency chain for projects using both libraries.
Related Issues