From 231455576dc6fbd8ea8cfe04a18fec755ba4dce1 Mon Sep 17 00:00:00 2001
From: Jon Schneider <jkschneider@gmail.com>
Date: Mon, 6 Feb 2017 13:46:59 -0800
Subject: [PATCH] Fix optional empty parentheses after annotation with no
 parameters

---
 .../rewrite/parse/OracleJdkParserVisitor.kt      | 16 +++++++++++++---
 .../com/netflix/rewrite/ast/AnnotationTest.kt    | 12 ++++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/rewrite-core/src/main/kotlin/com/netflix/rewrite/parse/OracleJdkParserVisitor.kt b/rewrite-core/src/main/kotlin/com/netflix/rewrite/parse/OracleJdkParserVisitor.kt
index b94894f..4dcd9cf 100644
--- a/rewrite-core/src/main/kotlin/com/netflix/rewrite/parse/OracleJdkParserVisitor.kt
+++ b/rewrite-core/src/main/kotlin/com/netflix/rewrite/parse/OracleJdkParserVisitor.kt
@@ -73,7 +73,17 @@ class OracleJdkParserVisitor(val path: Path, val source: String): TreePathScanne
             }
 
             Tr.Annotation.Arguments(args, format(argsPrefix))
-        } else null
+        } else {
+            val remaining = source.substring(cursor, node.endPos())
+
+            // NOTE: technically, if there is code like this, we have a bug, but seems exceedingly unlikely:
+            // @MyAnnotation /* Comment () that contains parentheses */ ()
+
+            if(remaining.contains("(") && remaining.contains(")")) {
+                val parenPrefix = sourceBefore("(")
+                Tr.Annotation.Arguments(listOf(Tr.Empty(format(sourceBefore(")")))), format(parenPrefix))
+            } else null
+        }
 
         return Tr.Annotation(name, args, node.type(), fmt)
     }
@@ -1178,7 +1188,7 @@ class OracleJdkParserVisitor(val path: Path, val source: String): TreePathScanne
      * and if not found in the remaining source, the empty String. If <code>stop</code> is reached before
      * <code>untilDelim</code> return the empty String.
      */
-    private fun sourceBefore(untilDelim: String, stop: Char? = null): String {
+    private fun sourceBefore(untilDelim: String, stop: Char? = null, stopIndex: Int? = null): String {
         val delimIndex = positionOfNext(untilDelim, stop)
         if(delimIndex < 0) {
             return "" // unable to find this delimiter
@@ -1189,7 +1199,7 @@ class OracleJdkParserVisitor(val path: Path, val source: String): TreePathScanne
         return prefix
     }
 
-    private fun positionOfNext(untilDelim: String, stop: Char? = null): Int {
+    private fun positionOfNext(untilDelim: String, stop: Char? = null, stopIndex: Int? = null): Int {
         var delimIndex = cursor
         var inMultiLineComment = false
         var inSingleLineComment = false
diff --git a/rewrite-core/src/test/kotlin/com/netflix/rewrite/ast/AnnotationTest.kt b/rewrite-core/src/test/kotlin/com/netflix/rewrite/ast/AnnotationTest.kt
index 2f8c29f..14d3e13 100644
--- a/rewrite-core/src/test/kotlin/com/netflix/rewrite/ast/AnnotationTest.kt
+++ b/rewrite-core/src/test/kotlin/com/netflix/rewrite/ast/AnnotationTest.kt
@@ -46,6 +46,18 @@ abstract class AnnotationTest(p: Parser): Parser by p {
         assertEquals("@SuppressWarnings(\"ALL\")", ann.printTrimmed())
     }
 
+    @Test
+    fun preserveOptionalEmptyParentheses() {
+        val a = parse("""
+            |@Deprecated ( )
+            |public class A {}
+        """)
+
+        val ann = a.classes[0].annotations[0]
+
+        assertEquals("@Deprecated ( )", ann.printTrimmed())
+    }
+
     @Test
     fun default() {
         val a = parse("""