From 02fec6e4a56fa9b96f0729862117ed5705147f53 Mon Sep 17 00:00:00 2001
From: Simon Ogorodnik <Simon.Ogorodnik@jetbrains.com>
Date: Tue, 18 Apr 2017 20:38:25 +0300
Subject: [PATCH] Add fine check of type inference when adding <> in completion

Add check if type inferred via type parameter of upper bound
 of extension receiver or value argument
 #KT-16161 fixed
---
 .../kotlin/idea/completion/InsertHandlerProvider.kt  |  7 +++++--
 .../handlers/basic/TypeInferedFromWrapperType.kt     | 12 ++++++++++++
 .../basic/TypeInferedFromWrapperType.kt.after        | 12 ++++++++++++
 .../BasicCompletionHandlerTestGenerated.java         |  6 ++++++
 4 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt
 create mode 100644 idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt.after

diff --git a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/InsertHandlerProvider.kt b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/InsertHandlerProvider.kt
index b08911a174e..c9a3d98a5b8 100644
--- a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/InsertHandlerProvider.kt
+++ b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/InsertHandlerProvider.kt
@@ -26,8 +26,8 @@ import org.jetbrains.kotlin.idea.core.ExpectedInfo
 import org.jetbrains.kotlin.idea.core.fuzzyType
 import org.jetbrains.kotlin.idea.util.CallType
 import org.jetbrains.kotlin.idea.util.fuzzyReturnType
-import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
 import org.jetbrains.kotlin.resolve.calls.util.getValueParametersCountFromFunctionType
+import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
 import org.jetbrains.kotlin.types.KotlinType
 import java.util.*
 
@@ -94,8 +94,11 @@ class InsertHandlerProvider(
 
         fun addPotentiallyInferred(type: KotlinType) {
             val descriptor = type.constructor.declarationDescriptor as? TypeParameterDescriptor
-            if (descriptor != null && descriptor in typeParameters) {
+            if (descriptor != null && descriptor in typeParameters && descriptor !in potentiallyInferred) {
                 potentiallyInferred.add(descriptor)
+                // Add possible inferred by type-arguments of upper-bound of parameter
+                // e.g. <T, C: Iterable<T>>, so T inferred from C
+                descriptor.upperBounds.filter { it.arguments.isNotEmpty() }.forEach(::addPotentiallyInferred)
             }
 
             if (type.isFunctionType && getValueParametersCountFromFunctionType(type) <= 1) {
diff --git a/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt b/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt
new file mode 100644
index 00000000000..be1703aeee5
--- /dev/null
+++ b/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt
@@ -0,0 +1,12 @@
+class Cn<T>
+
+fun <T, C: Cn<T>> C.some(arg: (T) -> Unit): C {
+    return this
+}
+
+fun main(args: Array<String>) {
+    val x = Cn<String>()
+    x.<caret>
+}
+
+//ELEMENT: some
diff --git a/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt.after b/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt.after
new file mode 100644
index 00000000000..7a28ebbad82
--- /dev/null
+++ b/idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt.after
@@ -0,0 +1,12 @@
+class Cn<T>
+
+fun <T, C: Cn<T>> C.some(arg: (T) -> Unit): C {
+    return this
+}
+
+fun main(args: Array<String>) {
+    val x = Cn<String>()
+    x.some {  }
+}
+
+//ELEMENT: some
diff --git a/idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/BasicCompletionHandlerTestGenerated.java b/idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/BasicCompletionHandlerTestGenerated.java
index 77500a77006..18d7e51acdc 100644
--- a/idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/BasicCompletionHandlerTestGenerated.java
+++ b/idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/BasicCompletionHandlerTestGenerated.java
@@ -216,6 +216,12 @@ public class BasicCompletionHandlerTestGenerated extends AbstractBasicCompletion
         doTest(fileName);
     }
 
+    @TestMetadata("TypeInferedFromWrapperType.kt")
+    public void testTypeInferedFromWrapperType() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/basic/TypeInferedFromWrapperType.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("TypeParameter.kt")
     public void testTypeParameter() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/basic/TypeParameter.kt");