From c178298ff4d3249c416cc5458418bf1cd5f11239 Mon Sep 17 00:00:00 2001
From: Andreas Rossbacher <andreas.rossbacher@airbnb.com>
Date: Wed, 8 Apr 2026 17:13:00 -0700
Subject: [PATCH] Fix flaky KSP error for @DeepLink methods in Kotlin objects

XProcessing's isStatic() for KSP relies on annotation type resolution
to detect @JvmStatic. This can intermittently fail during incremental
compilation with KSP2's Analysis API, causing methods in Kotlin object
declarations to appear non-static.

Add a fallback check in verifyMethod() that also accepts methods whose
enclosing type is a Kotlin object, since all methods in objects are
effectively static in JVM bytecode regardless of @JvmStatic.
---
 .../deeplinkdispatch/DeepLinkProcessor.kt     | 10 ++-
 .../DeepLinkProcessorKspTest.kt               | 70 +++++++++++++++++++
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/deeplinkdispatch-processor/src/main/java/com/airbnb/deeplinkdispatch/DeepLinkProcessor.kt b/deeplinkdispatch-processor/src/main/java/com/airbnb/deeplinkdispatch/DeepLinkProcessor.kt
index 792df3ee..16f90ab7 100644
--- a/deeplinkdispatch-processor/src/main/java/com/airbnb/deeplinkdispatch/DeepLinkProcessor.kt
+++ b/deeplinkdispatch-processor/src/main/java/com/airbnb/deeplinkdispatch/DeepLinkProcessor.kt
@@ -344,7 +344,15 @@ class DeepLinkProcessor(
     private fun validClassElement(classElement: XTypeElement) = classElement.isActivity() || classElement.isHandler()
 
     private fun verifyMethod(methodElement: XMethodElement) {
-        if (!methodElement.isStatic()) {
+        // XProcessing's isStatic() for KSP relies on annotation type resolution to detect
+        // @JvmStatic. This resolution can intermittently fail during incremental compilation
+        // with KSP2's Analysis API, causing isStatic() to return false for methods that are
+        // actually @JvmStatic inside a Kotlin object. As a workaround, we also accept methods
+        // whose enclosing type is a Kotlin object or companion object, since all methods in
+        // these types are effectively static in the JVM bytecode.
+        val enclosingElement = methodElement.enclosingElement
+        val isInKotlinObject = enclosingElement is XTypeElement && enclosingElement.isKotlinObject()
+        if (!methodElement.isStatic() && !isInKotlinObject) {
             throw DeepLinkProcessorException(
                 element = methodElement,
                 errorMessage = "Only static methods can be annotated with @${DEEP_LINK_CLASS.simpleName}",
diff --git a/deeplinkdispatch-processor/src/test/java/com/airbnb/deeplinkdispatch/DeepLinkProcessorKspTest.kt b/deeplinkdispatch-processor/src/test/java/com/airbnb/deeplinkdispatch/DeepLinkProcessorKspTest.kt
index 0b95ead3..25b13f01 100644
--- a/deeplinkdispatch-processor/src/test/java/com/airbnb/deeplinkdispatch/DeepLinkProcessorKspTest.kt
+++ b/deeplinkdispatch-processor/src/test/java/com/airbnb/deeplinkdispatch/DeepLinkProcessorKspTest.kt
@@ -1449,4 +1449,74 @@ class DeepLinkProcessorKspTest : BaseDeepLinkProcessorTest() {
             )
         }
     }
+
+    /**
+     * Verifies that methods inside a Kotlin `object` with @JvmStatic compile successfully.
+     * This exercises the isInKotlinObject fallback in verifyMethod(), which works around
+     * intermittent KSP annotation resolution failures where isStatic() returns false
+     * for @JvmStatic methods in object declarations.
+     */
+    @Test
+    fun testMethodInKotlinObjectWithJvmStaticCompiles() {
+        val kotlinObjectSource =
+            Source.KotlinSource(
+                "com/example/SampleDeepLinks.kt",
+                """
+                 package com.example
+                 import android.content.Context
+                 import android.content.Intent
+                 import com.airbnb.deeplinkdispatch.DeepLink
+
+                 object SampleDeepLinks {
+                     @DeepLink("airbnb://example.com/deepLink")
+                     @JvmStatic
+                     fun intentForDeepLink(context: Context): Intent = Intent()
+                 }
+                 """,
+            )
+        val results =
+            listOf(
+                compileIncremental(
+                    sourceFiles = listOf(kotlinObjectSource, module, fakeBaseDeeplinkDelegateJava),
+                    useKsp = true,
+                ),
+            )
+        results.forEach { result ->
+            assertThat(result.result.exitCode)
+                .isEqualTo(KotlinCompilation.ExitCode.OK)
+        }
+    }
+
+    /**
+     * Verifies that a non-static method (no @JvmStatic) in a plain class still fails.
+     */
+    @Test
+    fun testNonStaticMethodInClassStillFails() {
+        val nonStaticSource =
+            Source.KotlinSource(
+                "com/example/SampleActivity.kt",
+                """
+                 package com.example
+                 import android.content.Context
+                 import android.content.Intent
+                 import com.airbnb.deeplinkdispatch.DeepLink
+
+                 class SampleActivity : android.app.Activity() {
+                     @DeepLink("airbnb://example.com/deepLink")
+                     fun intentFromNoStatic(context: Context): Intent = Intent()
+                 }
+                 """,
+            )
+        val results =
+            listOf(
+                compileIncremental(
+                    sourceFiles = listOf(nonStaticSource, module, fakeBaseDeeplinkDelegateJava),
+                    useKsp = true,
+                ),
+            )
+        assertCompileError(
+            results = results,
+            errorMessage = "Only static methods can be annotated",
+        )
+    }
 }