From f4da6c2cc60bf02c9141abd594728b7d29ad16d1 Mon Sep 17 00:00:00 2001
From: Vyacheslav Gerasimov <vyacheslav.gerasimov@jetbrains.com>
Date: Tue, 29 Aug 2017 01:20:00 +0300
Subject: [PATCH] UAST: findAttributeValue returns default value when no
 declared value found

---
 .../uast/kotlin/declarations/KotlinUAnnotation.kt    | 12 +++++++++++-
 plugins/uast-kotlin/tests/KotlinUastApiTest.kt       |  8 ++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/declarations/KotlinUAnnotation.kt b/plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/declarations/KotlinUAnnotation.kt
index 5fac24f2852..e68e1e8d9b7 100644
--- a/plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/declarations/KotlinUAnnotation.kt
+++ b/plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/declarations/KotlinUAnnotation.kt
@@ -42,7 +42,7 @@ class KotlinUAnnotation(
     }
 
     override fun findAttributeValue(name: String?): UExpression? =
-            findDeclaredAttributeValue(name)
+            findDeclaredAttributeValue(name) ?: findAttributeDefaultValue(name ?: "value")
 
     override fun findDeclaredAttributeValue(name: String?): UExpression? {
         return attributeValues.find {
@@ -52,5 +52,15 @@ class KotlinUAnnotation(
         }?.expression
     }
 
+    private fun findAttributeDefaultValue(name: String): UExpression? {
+        val parameter = resolvedAnnotation
+                                ?.annotationClass
+                                ?.unsubstitutedPrimaryConstructor
+                                ?.valueParameters
+                                ?.find { it.name.asString() == name } ?: return null
+
+        val defaultValue = (parameter.source.getPsi() as? KtParameter)?.defaultValue ?: return null
+        return getLanguagePlugin().convertWithParent(defaultValue)
+    }
 }
 
diff --git a/plugins/uast-kotlin/tests/KotlinUastApiTest.kt b/plugins/uast-kotlin/tests/KotlinUastApiTest.kt
index 65feb55de6b..467cc501127 100644
--- a/plugins/uast-kotlin/tests/KotlinUastApiTest.kt
+++ b/plugins/uast-kotlin/tests/KotlinUastApiTest.kt
@@ -104,4 +104,12 @@ class KotlinUastApiTest : AbstractKotlinUastTest() {
             assertEquals("String", elvisExpression.getExpressionType()!!.presentableText)
         }
     }
+
+    @Test fun testFindAttributeDefaultValue() {
+        doTest("AnnotationParameters") { _, file ->
+            val witDefaultValue = file.findElementByText<UAnnotation>("@WithDefaultValue")
+            assertEquals(42, witDefaultValue.findAttributeValue("value")!!.evaluate())
+            assertEquals(42, witDefaultValue.findAttributeValue(null)!!.evaluate())
+        }
+    }
 }