From bf4df4a9794fac085a2a2fba10b7b5bf1d69f354 Mon Sep 17 00:00:00 2001
From: Kyle Thomson <kylthoms@amazon.com>
Date: Tue, 18 Jul 2017 15:15:06 -0700
Subject: [PATCH] Enhance Java builder completion for superclasses and generics

---
 .../psi/filters/getters/BuilderCompletion.kt  |  9 ++++----
 ...icBuilderWithInterfaceAndGenerics-out.java | 23 +++++++++++++++++++
 ...StaticBuilderWithInterfaceAndGenerics.java | 23 +++++++++++++++++++
 .../completion/SmartTypeCompletionTest.java   |  1 +
 4 files changed, 52 insertions(+), 4 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics-out.java
 create mode 100644 java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics.java

diff --git a/java/java-impl/src/com/intellij/psi/filters/getters/BuilderCompletion.kt b/java/java-impl/src/com/intellij/psi/filters/getters/BuilderCompletion.kt
index 297dbaced577..48bc1eb73a1d 100644
--- a/java/java-impl/src/com/intellij/psi/filters/getters/BuilderCompletion.kt
+++ b/java/java-impl/src/com/intellij/psi/filters/getters/BuilderCompletion.kt
@@ -44,10 +44,11 @@ internal class BuilderCompletion(private val expectedType: PsiClassType, private
   }
 
   private fun methodsReturning(containingClass: PsiClass, returnedClass: PsiClass, isStatic: Boolean): Collection<List<PsiMethod>> {
-    return containingClass.methods
-      .filter { it.hasModifierProperty(PsiModifier.STATIC) == isStatic &&
-                returnedClass == PsiUtil.resolveClassInClassTypeOnly(it.returnType) &&
-                PsiUtil.isAccessible(it, place, null) }
+    return containingClass.allMethodsAndTheirSubstitutors
+      .filter { it.first.hasModifierProperty(PsiModifier.STATIC) == isStatic &&
+                returnedClass == PsiUtil.resolveClassInClassTypeOnly(it.second.substitute(it.first.returnType)) &&
+                PsiUtil.isAccessible(it.first, place, null) }
+      .map { it.first }
       .groupBy { it.name }
       .values
   }
diff --git a/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics-out.java b/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics-out.java
new file mode 100644
index 000000000000..a7fa402b315d
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics-out.java
@@ -0,0 +1,23 @@
+public class S {
+
+  {
+    Map m = Map.build()<caret>.get();
+  }
+
+}
+
+class Map {
+  static MapBuilder build() {}
+
+  interface BaseBuilder<T> {
+    T get();
+  }
+
+  interface MapBuilder extends BaseBuilder<Map> {
+
+  }
+
+  static class Builder implements MapBuilder {
+    Map get() {}
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics.java b/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics.java
new file mode 100644
index 000000000000..4d08bcf4b1b6
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/smartType/StaticBuilderWithInterfaceAndGenerics.java
@@ -0,0 +1,23 @@
+public class S {
+
+  {
+    Map m = bui<caret>
+  }
+
+}
+
+class Map {
+  static MapBuilder build() {}
+
+  interface BaseBuilder<T> {
+    T get();
+  }
+
+  interface MapBuilder extends BaseBuilder<Map> {
+
+  }
+
+  static class Builder implements MapBuilder {
+    Map get() {}
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
index 886fd3441442..907207497a9d 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
@@ -1249,6 +1249,7 @@ public class SmartTypeCompletionTest extends LightFixtureCompletionTestCase {
 
   public void testStaticBuilder() { doTest(); }
   public void testStaticBuilderWithArguments() { doTest(); }
+  public void testStaticBuilderWithInterfaceAndGenerics() { doTest(); }
 
   public void testStaticBuilderWithGenerics() {
     configureByTestName();