Fix Aliases as TypeArgument

interop/ksp/src/main/kotlin/com/squareup/kotlinpoet/ksp/KsTypes.kt

@@ -15,6 +15,7 @@
  */
 package com.squareup.kotlinpoet.ksp
 
+import com.google.devtools.ksp.symbol.ClassKind
 import com.google.devtools.ksp.symbol.KSClassDeclaration
 import com.google.devtools.ksp.symbol.KSType
 import com.google.devtools.ksp.symbol.KSTypeAlias
@@ -63,6 +64,12 @@ internal fun KSType.toTypeName(
   }
   val type = when (val decl = declaration) {
     is KSClassDeclaration -> {
+      val arguments = if (decl.classKind == ClassKind.ANNOTATION_CLASS) {
+        arguments
+      } else {
+        typeArguments
+      }
+
       decl.toClassName().withTypeArguments(arguments.map { it.toTypeName(typeParamResolver) })
     }
     is KSTypeParameter -> typeParamResolver[decl.name.getShortName()]

interop/ksp/test-processor/src/test/kotlin/com/squareup/kotlinpoet/ksp/test/processor/TestProcessorTest.kt

@@ -438,6 +438,47 @@ class TestProcessorTest {
     )
   }
 
+  @Test
+  fun aliasAsTypeArgument() {
+    val compilation = prepareCompilation(
+      kotlin(
+        "Example.kt",
+        """
+           package test
+
+           import com.squareup.kotlinpoet.ksp.test.processor.ExampleAnnotation
+
+           typealias Alias997 = Map<String, Int>
+
+           @ExampleAnnotation
+           interface AliasAsTypeArgument {
+              fun bar(arg1: List<Alias997>)
+           }
+           """,
+      ),
+    )
+
+    val result = compilation.compile()
+    assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.OK)
+    val generatedFileText = File(compilation.kspSourcesDir, "kotlin/test/TestAliasAsTypeArgument.kt")
+      .readText()
+
+    assertThat(generatedFileText).isEqualTo(
+      """
+    package test
+
+    import kotlin.Unit
+    import kotlin.collections.List
+
+    public class AliasAsTypeArgument {
+      public fun bar(arg1: List<Alias997>): Unit {
+      }
+    }
+
+      """.trimIndent(),
+    )
+  }
+
   private fun prepareCompilation(vararg sourceFiles: SourceFile): KotlinCompilation {
     return KotlinCompilation()
       .apply {