test case and possible fix for messaging when type resolution fails due to invalid syntax of a generic property (#1527)

moshi-kotlin-codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorProvider.kt

@@ -87,9 +87,9 @@ private class JsonClassSymbolProcessor(
 
       if (!jsonClassAnnotation.generateAdapter) continue
 
-      val originatingFile = type.containingFile!!
-      val adapterGenerator = adapterGenerator(logger, resolver, type) ?: return emptyList()
       try {
+        val originatingFile = type.containingFile!!
+        val adapterGenerator = adapterGenerator(logger, resolver, type) ?: return emptyList()
         val preparedAdapter = adapterGenerator
           .prepare(generateProguardRules) { spec ->
             spec.toBuilder()

moshi-kotlin-codegen/src/test/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorTest.kt

@@ -538,6 +538,24 @@ class JsonClassSymbolProcessorTest {
     assertThat(result.messages).contains("JsonQualifier @UpperCase must have RUNTIME retention")
   }
 
+  @Test
+  fun invalidGenericSyntaxErrorMessaging() {
+    val result = compile(
+      kotlin(
+        "source.kt",
+        """
+          package test
+          import com.squareup.moshi.JsonClass
+
+          @JsonClass(generateAdapter = true)
+          data class ElementEnvelope(val elements: List)
+          """,
+      ),
+    )
+    assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.COMPILATION_ERROR)
+    assertThat(result.messages).contains("Error preparing ElementEnvelope")
+  }
+
   @Test
   fun `TypeAliases with the same backing type should share the same adapter`() {
     val result = compile(