Extraction Engine: Generate function/property accessor with expression body (whenever applicable)

#KT-6405 Fixed

idea/testData/refactoring/extractFunction/basic/localExtraction.kt.after

@@ -1,8 +1,6 @@
 fun foo(a: Int): Int {
     // SIBLING:
-    fun i(): Int {
-        return a + 10
-    }
+    fun i() = a + 10
 
     return i()
 }

idea/testData/refactoring/extractFunction/basic/noConflictWithInnerFunction.kt.after

@@ -1,9 +1,7 @@
 fun foo() {
     val a = 1
     // SIBLING:
-    fun b1(): Boolean {
-        return a > 0
-    }
+    fun b1() = a > 0
 
     if (b1()) {
         fun b(): Int { return 0 }

idea/testData/refactoring/extractFunction/basic/traitFunction.kt.after

@@ -3,7 +3,5 @@ trait T{
         return i()
     }
 
-    fun i(): Int {
-        return 1
-    }
+    fun i() = 1
 }

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInIfCondition.kt.after

@@ -8,6 +8,4 @@ fun foo(a: Int): Int {
     return if (b(a, b)) 1 else if (a - b < 0) 2 else b
 }
 
-private fun b(a: Int, b: Int): Boolean {
-    return a + b > 0
-}
+private fun b(a: Int, b: Int) = a + b > 0

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInIfElse.kt.after

@@ -8,6 +8,4 @@ fun foo(a: Int): Int {
     return if (a + b > 0) 1 else i(a, b)
 }
 
-private fun i(a: Int, b: Int): Int {
-    return if (a - b < 0) 2 else b
-}
+private fun i(a: Int, b: Int) = if (a - b < 0) 2 else b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInIfThen.kt.after

@@ -4,6 +4,4 @@ fun foo(a: Int): Int {
     return if (a + b > 0) i() else if (a - b < 0) 2 else b
 }
 
-private fun i(): Int {
-    return 1
-}
+private fun i() = 1

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInWhenBranch.kt.after

@@ -10,6 +10,4 @@ fun foo(a: Int): Int {
     }
 }
 
-private fun i(b: Int): Int {
-    return b
-}
+private fun i(b: Int) = b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInWhenCondition.kt.after

@@ -8,6 +8,4 @@ fun foo(a: Int): Int {
     }
 }
 
-private fun i(): Int {
-    return 0
-}
+private fun i() = 0

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExprInWhenSubject.kt.after

@@ -12,6 +12,4 @@ fun foo(a: Int): Int {
     }
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalExpressionBodyFunction.kt.after

@@ -5,6 +5,4 @@
 // SIBLING:
 fun foo(a: Int, b: Int): Int = i(a, b)
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/evalIfExpr.kt.after

@@ -8,6 +8,4 @@ fun foo(a: Int): Int {
     return i(a, b) 
 }
 
-private fun i(a: Int, b: Int): Int {
-    return if (a + b > 0) 1 else if (a - b < 0) 2 else b
-}
+private fun i(a: Int, b: Int) = if (a + b > 0) 1 else if (a - b < 0) 2 else b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/simpleEvalExpr.kt.after

@@ -8,6 +8,4 @@ fun foo(a: Int): Int {
     return i(a, b)
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/trailingLambdaEmptyArgList.kt.after

@@ -5,6 +5,4 @@ fun foo(t: Array<Int>) {
     t.check(function())
 }
 
-private fun function(): (Int) -> Boolean {
-    return { it + 1 > 1 }
-}
+private fun function() = { it + 1 > 1 }

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/trailingLambdaNoArgList.kt.after

@@ -5,6 +5,4 @@ fun foo(t: Array<Int>) {
     t.check(function())
 }
 
-private fun function(): (Int) -> Boolean {
-    return { it + 1 > 1 }
-}
+private fun function() = { it + 1 > 1 }

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/trailingLambdaNonEmptyArgList.kt.after

@@ -5,6 +5,4 @@ fun foo(t: Array<Int>) {
     t.check(1, 2, function())
 }
 
-private fun function(): (Int) -> Boolean {
-    return { it + 1 > 1 }
-}
+private fun function() = { it + 1 > 1 }

idea/testData/refactoring/extractFunction/controlFlow/evaluateExpression/trailingLambdaNonEmptyArgListWithNamedArgs.kt.after

@@ -5,6 +5,4 @@ fun foo(t: Array<Int>) {
     t.check(a = 1, b = 2, f = function())
 }
 
-private fun function(): (Int) -> Boolean {
-    return { it + 1 > 1 }
-}
+private fun function() = { it + 1 > 1 }

idea/testData/refactoring/extractFunction/controlFlow/throws/evalExpressionWithThrow.kt.after

@@ -11,6 +11,4 @@ fun foo(a: Int): Int {
     return t
 }
 
-private fun i(a: Int, b: Int): Int {
-    return if (a > 0) throw Exception("") else a + b
-}
+private fun i(a: Int, b: Int) = if (a > 0) throw Exception("") else a + b

idea/testData/refactoring/extractFunction/defaultContainer/anonymousObject.kt.after

@@ -5,9 +5,7 @@ class A {
                 return i()
             }
 
-            private fun i(): Int {
-                return a + b - 1
-            }
+            private fun i() = a + b - 1
         }
     }
 }

idea/testData/refactoring/extractFunction/defaultContainer/classFunction.kt.after

@@ -8,8 +8,6 @@ class A {
             return i(a, b)
         }
 
-        private fun i(a: Int, b: Int): Int {
-            return a + b - 1
-        }
+        private fun i(a: Int, b: Int) = a + b - 1
     }
 }

idea/testData/refactoring/extractFunction/defaultContainer/lambda.kt.after

@@ -9,7 +9,5 @@ class A {
         }.invoke()
     }
 
-    private fun i(a: Int, b: Int): Int {
-        return a + b - 1
-    }
+    private fun i(a: Int, b: Int) = a + b - 1
 }

idea/testData/refactoring/extractFunction/defaultContainer/localClass.kt.after

@@ -5,9 +5,7 @@ class A {
                 return i()
             }
 
-            private fun i(): Int {
-                return a + b - 1
-            }
+            private fun i() = a + b - 1
         }
 
         return L().invoke()

idea/testData/refactoring/extractFunction/defaultContainer/localFunction.kt.after

@@ -1,7 +1,5 @@
 fun foo(a: Int, b: Int): Int {
-    fun i(): Int {
-        return a + b - 1
-    }
+    fun i() = a + b - 1
 
     fun bar() {
         return i()

idea/testData/refactoring/extractFunction/defaultContainer/nestedLambda.kt.after

@@ -9,7 +9,5 @@ class A {
         }.invoke()
     }
 
-    private fun i(a: Int, b: Int): Int {
-        return a + b - 1
-    }
+    private fun i(a: Int, b: Int) = a + b - 1
 }

idea/testData/refactoring/extractFunction/defaultContainer/topLevelFunction.kt.after

@@ -6,6 +6,4 @@ fun foo(a: Int, b: Int): Int {
     return i(a, b)
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b - 1
-}
+private fun i(a: Int, b: Int) = a + b - 1

idea/testData/refactoring/extractFunction/delegation/delegationByExpression.kt.after

@@ -8,6 +8,4 @@ class A(a: Int, b: Int): T
 
 class B(a: Int, b: Int): T by A(i(a, b), a - b)
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/delegation/delegationByExpressionFull.kt.after

@@ -6,6 +6,4 @@ class A(a: Int, b: Int): T
 
 class B(t: T): T by t(t)
 
-private fun t(t: T): T {
-    return t
-}
+private fun t(t: T) = t

idea/testData/refactoring/extractFunction/delegation/delegationBySuperCall.kt.after

@@ -6,6 +6,4 @@ open class A(a: Int, b: Int)
 
 class B(a: Int, b: Int): A(i(a, b), a - b)
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/duplicates/insertAfterDuplicates.kt.after

@@ -3,7 +3,5 @@ class A {
     val x = i()
     val y = i()
 
-    private fun i(): Int {
-        return 1 + 1
-    }
+    private fun i() = 1 + 1
 }

idea/testData/refactoring/extractFunction/duplicates/insertBeforeDuplicates.kt.after

@@ -4,6 +4,4 @@ fun foo() {
     val y = i()
 }
 
-private fun i(): Int {
-    return 1 + 1
-}
+private fun i() = 1 + 1

idea/testData/refactoring/extractFunction/duplicates/nestedStrongMatch.kt.after

@@ -5,6 +5,4 @@ fun main(args: Array<String>) {
     val y = i()
 }
 
-private fun i(): Int {
-    return 1 + 1
-}
+private fun i() = 1 + 1

idea/testData/refactoring/extractFunction/duplicates/notNullAssertion.kt.after

@@ -11,6 +11,4 @@ fun foo(): Int {
     }
 }
 
-private fun i(s: String?): Int {
-    return s!!.length
-}
+private fun i(s: String?) = s!!.length

idea/testData/refactoring/extractFunction/duplicates/singleExpression.kt.after

@@ -24,6 +24,4 @@ fun bar() {
     i(f(), f())
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b * a
-}
+private fun i(a: Int, b: Int) = a + b * a

idea/testData/refactoring/extractFunction/initializers/accessors/memberProperty.kt.after

@@ -1,7 +1,5 @@
 class A(val a: Int, val b: Int) {
     val foo: Int get() = i() - 1
 
-    private fun i(): Int {
-        return a + b
-    }
+    private fun i() = a + b
 }

idea/testData/refactoring/extractFunction/initializers/accessors/memberPropertyWithLambda.kt.after

@@ -1,7 +1,5 @@
 class A(val a: Int, val b: Int) {
     val foo: Int get() = { i() - 1 }.invoke()
 
-    private fun i(): Int {
-        return a + b
-    }
+    private fun i() = a + b
 }

idea/testData/refactoring/extractFunction/initializers/accessors/topLevelProperty.kt.after

@@ -2,6 +2,4 @@ val a = 1
 val b = 1
 val foo: Int get() = i() - 1
 
-private fun i(): Int {
-    return a + b
-}
+private fun i() = a + b

idea/testData/refactoring/extractFunction/initializers/accessors/topLevelPropertyWithLambda.kt.after

@@ -2,6 +2,4 @@ val a = 1
 val b = 1
 val foo: Int get() = { i() - 1 }.invoke()
 
-private fun i(): Int {
-    return a + b
-}
+private fun i() = a + b

idea/testData/refactoring/extractFunction/initializers/classes/classInitializer.kt.after

@@ -5,7 +5,5 @@ class A(val a: Int, b: Int) {
         println(i(b) - 1)
     }
 
-    private fun i(b: Int): Int {
-        return a + b
-    }
+    private fun i(b: Int) = a + b
 }

idea/testData/refactoring/extractFunction/initializers/classes/classInitializerWithLambda.kt.after

@@ -5,7 +5,5 @@ class A(val a: Int, b: Int) {
         println({ i(b) - 1 }.invoke())
     }
 
-    private fun i(b: Int): Int {
-        return a + b
-    }
+    private fun i(b: Int) = a + b
 }

idea/testData/refactoring/extractFunction/initializers/classes/classParameters.kt.after

@@ -3,6 +3,4 @@
 val n = 1
 class A(val a: Int, val b: Int = i(a))
 
-private fun i(a: Int): Int {
-    return a + n
-}
+private fun i(a: Int) = a + n

idea/testData/refactoring/extractFunction/initializers/classes/classParametersWithLambda.kt.after

@@ -3,6 +3,4 @@
 val n = 1
 class A(val a: Int, val b: Int = { i(a) }.invoke())
 
-private fun i(a: Int): Int {
-    return a + n
-}
+private fun i(a: Int) = a + n

idea/testData/refactoring/extractFunction/initializers/functions/localFunction.kt.after

@@ -3,9 +3,7 @@
 // PARAM_DESCRIPTOR: value-parameter val a: kotlin.Int defined in bar.foo
 // PARAM_DESCRIPTOR: value-parameter val b: kotlin.Int defined in bar.foo
 fun bar(n: Int) {
-    fun i(a: Int, b: Int): Int {
-        return a + b - n
-    }
+    fun i(a: Int, b: Int) = a + b - n
 
     fun foo(a: Int, b: Int) = i(a, b) - 1
 }

idea/testData/refactoring/extractFunction/initializers/functions/localFunctionWithLambda.kt.after

@@ -3,9 +3,7 @@
 // PARAM_DESCRIPTOR: value-parameter val a: kotlin.Int defined in bar.foo
 // PARAM_DESCRIPTOR: value-parameter val b: kotlin.Int defined in bar.foo
 fun bar(n: Int) {
-    fun i(a: Int, b: Int): Int {
-        return a + b - n
-    }
+    fun i(a: Int, b: Int) = a + b - n
 
     fun foo(a: Int, b: Int) = { i(a, b) - 1 }.invoke()
 }

idea/testData/refactoring/extractFunction/initializers/functions/memberFunction.kt.after

@@ -5,7 +5,5 @@
 class A(val n: Int) {
     fun foo(a: Int, b: Int) = i(a, b) - 1
 
-    private fun i(a: Int, b: Int): Int {
-        return a + b - n
-    }
+    private fun i(a: Int, b: Int) = a + b - n
 }

idea/testData/refactoring/extractFunction/initializers/functions/memberFunctionParameters.kt.after

@@ -3,7 +3,5 @@
 class A(val n: Int) {
     fun foo(a: Int, b: Int = i(a)) = a + b - n - 1
 
-    private fun i(a: Int): Int {
-        return a + n
-    }
+    private fun i(a: Int) = a + n
 }

idea/testData/refactoring/extractFunction/initializers/functions/memberFunctionParametersWithLambda.kt.after

@@ -3,7 +3,5 @@
 class A(val n: Int) {
     fun foo(a: Int, b: Int = { i(a) }.invoke()) = a + b - n - 1
 
-    private fun i(a: Int): Int {
-        return a + n
-    }
+    private fun i(a: Int) = a + n
 }

idea/testData/refactoring/extractFunction/initializers/functions/memberFunctionWithLambda.kt.after

@@ -5,7 +5,5 @@
 class A(val n: Int) {
     fun foo(a: Int, b: Int) = { i(a, b) - 1 }.invoke()
 
-    private fun i(a: Int, b: Int): Int {
-        return a + b - n
-    }
+    private fun i(a: Int, b: Int) = a + b - n
 }

idea/testData/refactoring/extractFunction/initializers/functions/topLevelFunction.kt.after

@@ -4,6 +4,4 @@
 // PARAM_DESCRIPTOR: value-parameter val b: kotlin.Int defined in foo
 fun foo(a: Int, b: Int) = i(a, b) - 1
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/initializers/functions/topLevelFunctionParameters.kt.after

@@ -3,6 +3,4 @@
 val n = 1
 fun foo(a: Int, b: Int = i(a)) = a + b - 1
 
-private fun i(a: Int): Int {
-    return a + n
-}
+private fun i(a: Int) = a + n

idea/testData/refactoring/extractFunction/initializers/functions/topLevelFunctionParametersWithLambda.kt.after

@@ -3,6 +3,4 @@
 val n = 1
 fun foo(a: Int, b: Int = { i(a) }) = a + b - 1
 
-private fun i(a: Int): Int {
-    return a + n
-}
+private fun i(a: Int) = a + n

idea/testData/refactoring/extractFunction/initializers/functions/topLevelFunctionWithLambda.kt.after

@@ -4,6 +4,4 @@
 // PARAM_DESCRIPTOR: value-parameter val b: kotlin.Int defined in foo
 fun foo(a: Int, b: Int) = { i(a, b) - 1 }.invoke()
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/initializers/properties/localProperty.kt.after

@@ -6,6 +6,4 @@ fun bar(a: Int, b: Int) {
     val foo = i(a, b) - 1
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/initializers/properties/localPropertyWithLambda.kt.after

@@ -6,6 +6,4 @@ fun bar(a: Int, b: Int) {
     val foo = { i(a, b) - 1 }.invoke()
 }
 
-private fun i(a: Int, b: Int): Int {
-    return a + b
-}
+private fun i(a: Int, b: Int) = a + b

idea/testData/refactoring/extractFunction/initializers/properties/memberProperty.kt.after

@@ -3,7 +3,5 @@
 class A(val a: Int, b: Int) {
     val foo = i(b) - 1
 
-    private fun i(b: Int): Int {
-        return a + b
-    }
+    private fun i(b: Int) = a + b
 }

idea/testData/refactoring/extractFunction/initializers/properties/memberPropertyWithLambda.kt.after

@@ -3,7 +3,5 @@
 class A(val a: Int, b: Int) {
     val foo = { i(b) - 1 }.invoke()
 
-    private fun i(b: Int): Int {
-        return a + b
-    }
+    private fun i(b: Int) = a + b
 }

idea/testData/refactoring/extractFunction/initializers/properties/multiDeclaration.kt.after

@@ -4,6 +4,4 @@ fun foo() {
     val (a, b) = pair()
 }
 
-private fun pair(): Pair<Int, Int> {
-    return 1 to 2
-}
+private fun pair() = 1 to 2

idea/testData/refactoring/extractFunction/initializers/properties/topLevelProperty.kt.after

@@ -2,6 +2,4 @@ val a = 1
 val b = 1
 val foo = i() - 1
 
-private fun i(): Int {
-    return a + b
-}
+private fun i() = a + b

idea/testData/refactoring/extractFunction/initializers/properties/topLevelPropertyWithLambda.kt.after

@@ -2,6 +2,4 @@ val a = 1
 val b = 1
 val foo = { i() - 1 }.invoke()
 
-private fun i(): Int {
-    return a + b
-}
+private fun i() = a + b

idea/testData/refactoring/extractFunction/parameters/candidateTypes/flexibleTypesWithNull.kt.after

@@ -7,6 +7,4 @@ fun test() {
     val n = i(property)
 }
 
-private fun i(property: String?): Int? {
-    return property?.length()
-}
+private fun i(property: String?) = property?.length()

idea/testData/refactoring/extractFunction/parameters/candidateTypes/flexibleTypesWithoutNull.kt.after

@@ -7,6 +7,4 @@ fun test() {
     val n = i(property)
 }
 
-private fun i(property: String): Int {
-    return property.length()
-}
+private fun i(property: String) = property.length()

idea/testData/refactoring/extractFunction/parameters/extractThis/explicitLabeledThisInMember.kt.after

@@ -19,6 +19,4 @@ public class A(): Z() {
     }
 }
 
-private fun i(a1: A, b1: A.B): Int {
-    return a1.a + b1.b + a1.z + b1.z
-}
+private fun i(a1: A, b1: A.B) = a1.a + b1.b + a1.z + b1.z

idea/testData/refactoring/extractFunction/parameters/extractThis/explicitThisInExtension.kt.after

@@ -7,6 +7,4 @@ fun Z.foo(): Int {
     return i() + 1
 }
 
-private fun Z.i(): Int {
-    return this.a
-}
+private fun Z.i() = this.a

idea/testData/refactoring/extractFunction/parameters/extractThis/explicitThisInMember.kt.after

@@ -19,6 +19,4 @@ public class A(): Z() {
     }
 }
 
-private fun i(a1: A, b1: A.B): Int {
-    return a1.a + b1.b + b1.z
-}
+private fun i(a1: A, b1: A.B) = a1.a + b1.b + b1.z

idea/testData/refactoring/extractFunction/parameters/extractThis/implicitAndExplicitLabeledThisInMember.kt.after

@@ -19,6 +19,4 @@ public class A(): Z() {
     }
 }
 
-private fun i(a1: A, b1: A.B): Int {
-    return a1.a + b1.b + a1.z + b1.z
-}
+private fun i(a1: A, b1: A.B) = a1.a + b1.b + a1.z + b1.z

idea/testData/refactoring/extractFunction/parameters/extractThis/implicitAndExplicitThisInExtension.kt.after

@@ -7,6 +7,4 @@ fun Z.foo(): Int {
     return i() + 1
 }
 
-private fun Z.i(): Int {
-    return this.a + a
-}
+private fun Z.i() = this.a + a

idea/testData/refactoring/extractFunction/parameters/extractThis/implicitThisInExtension.kt.after

@@ -7,6 +7,4 @@ fun Z.foo(): Int {
     return i() + 1
 }
 
-private fun Z.i(): Int {
-    return a
-}
+private fun Z.i() = a

idea/testData/refactoring/extractFunction/parameters/extractThis/implicitThisInMember.kt.after

@@ -19,6 +19,4 @@ public class A(): Z() {
     }
 }
 
-private fun i(a1: A, b1: A.B): Int {
-    return a1.a + b1.b + b1.z
-}
+private fun i(a1: A, b1: A.B) = a1.a + b1.b + b1.z

idea/testData/refactoring/extractFunction/parameters/extractThis/qualifiedThisAsArgument.kt.after

@@ -9,9 +9,7 @@ class A {
     fun B.foo() = i(this@A, this)
 }
 
-private fun i(a1: A, b: B): Int {
-    return a1.a + b.b
-}
+private fun i(a1: A, b: B) = a1.a + b.b
 
 class B {
     val b = 1

idea/testData/refactoring/extractFunction/parameters/it/innerIt.kt.after

@@ -9,6 +9,4 @@ fun foo(t: Array<Array<Int>>) {
     }
 }
 
-private fun i(it: Int): Int {
-    return it + 1
-}
+private fun i(it: Int) = it + 1

idea/testData/refactoring/extractFunction/parameters/it/lambdaWithIt.kt.after

@@ -9,6 +9,4 @@ fun foo(t: Array<Int>) {
     }
 }
 
-private fun b(t: Array<Int>): Boolean {
-    return t.check { it + 1 > 1 }
-}
+private fun b(t: Array<Int>) = t.check { it + 1 > 1 }

idea/testData/refactoring/extractFunction/parameters/it/outerIt.kt.after

@@ -9,6 +9,4 @@ fun foo(t: Array<Array<Int>>) {
     }
 }
 
-private fun b(it: Array<Int>): Boolean {
-    return it.check { it + 1 > 1 }
-}
+private fun b(it: Array<Int>) = it.check { it + 1 > 1 }

idea/testData/refactoring/extractFunction/parameters/it/simpleIt.kt.after

@@ -9,6 +9,4 @@ fun foo(t: Array<Int>) {
     }
 }
 
-private fun i(it: Int): Int {
-    return it + 1
-}
+private fun i(it: Int) = it + 1

idea/testData/refactoring/extractFunction/parameters/misc/multipleOccurrences.kt.after

@@ -9,6 +9,4 @@ fun foo(a: Int, b: Int, c: Int): Int {
     return i(a, b, c)
 }
 
-private fun i(a: Int, b: Int, c: Int): Int {
-    return (a + b * a - c) + b * c
-}
+private fun i(a: Int, b: Int, c: Int) = (a + b * a - c) + b * c

idea/testData/refactoring/extractFunction/parameters/misc/usagesInCallArgs.kt.after

@@ -13,9 +13,7 @@ public class A() {
     }
 }
 
-private fun i(a: A, t: Int, u: Int, x: Int): Int {
-    return a.bar(t - x, u + x)
-}
+private fun i(a: A, t: Int, u: Int, x: Int) = a.bar(t - x, u + x)
 
 fun foo(a: A, x: Int): Int {
     val t = 10

idea/testData/refactoring/extractFunction/typeParameters/simpleTypeParameter.kt.after

@@ -9,6 +9,4 @@ fun foo<V: Data>(v: V): Pair<Int, V> {
     return pair(v)
 }
 
-private fun <V : Data> pair(v: V): Pair<Int, V> {
-    return Pair(v.x + 10, v)
-}
+private fun <V : Data> pair(v: V) = Pair(v.x + 10, v)

idea/testData/refactoring/extractFunction/typeParameters/simpleTypeParameterWithConstraint.kt.after

@@ -10,6 +10,4 @@ fun foo<V: Data>(v: V): Pair<Int, V> where V: DataEx {
     return pair(v)
 }
 
-private fun <V : Data> pair(v: V): Pair<Int, V> where V : DataEx {
-    return Pair(v.x + 10, v)
-}
+private fun <V : Data> pair(v: V) where V : DataEx = Pair(v.x + 10, v)

idea/testData/refactoring/extractFunction/typeParameters/typeParamInArgument.kt.after

@@ -9,6 +9,4 @@ class A<T> {
     }
 }
 
-private fun <T> i(d: Data<T>): Int {
-    return d.t + 1
-}
+private fun <T> i(d: Data<T>) = d.t + 1

idea/testData/refactoring/extractFunction/typeParameters/typeParametersAndConstraintsCombined1.kt.after

@@ -17,6 +17,4 @@ class A<T: Data>(val t: T) where T: DataEx {
     }
 }
 
-private fun <T : Data, U : Data, V : Data> i(a: A<T>, b: A.B<U>, v: V): Int where T : DataEx, U : DataExEx, V : DataEx {
-    return a.t.x + b.u.x + v.x
-}
+private fun <T : Data, U : Data, V : Data> i(a: A<T>, b: A.B<U>, v: V) where T : DataEx, U : DataExEx, V : DataEx = a.t.x + b.u.x + v.x

idea/testData/refactoring/extractFunction/typeParameters/typeParametersAndConstraintsCombined2.kt.after

@@ -14,7 +14,5 @@ class A<T: Data>(val t: T) where T: DataEx {
         }
     }
 
-    private fun <U : Data, V : Data> B<U>.i(v: V): Int where U : DataExEx, V : DataEx {
-        return t.x + u.x + v.x
-    }
+    private fun <U : Data, V : Data> B<U>.i(v: V) where U : DataExEx, V : DataEx = t.x + u.x + v.x
 }

idea/testData/refactoring/extractFunction/typeParameters/typeParametersAndConstraintsCombined3.kt.after

@@ -11,8 +11,6 @@ class A<T: Data>(val t: T) where T: DataEx {
             return i(v)
         }
 
-        private fun <V : Data> i(v: V): Int where V : DataEx {
-            return t.x + u.x + v.x
-        }
+        private fun <V : Data> i(v: V) where V : DataEx = t.x + u.x + v.x
     }
 }

idea/testData/refactoring/extractFunction/typeParameters/typeParametersCombined1.kt.after

@@ -15,6 +15,4 @@ class A<T: Data>(val t: T) {
     }
 }
 
-private fun <T : Data, U : Data, V : Data> i(a: A<T>, b: A.B<U>, v: V): Int {
-    return a.t.x + b.u.x + v.x
-}
+private fun <T : Data, U : Data, V : Data> i(a: A<T>, b: A.B<U>, v: V) = a.t.x + b.u.x + v.x

idea/testData/refactoring/extractFunction/typeParameters/typeParametersCombined2.kt.after

@@ -12,7 +12,5 @@ class A<T: Data>(val t: T) {
         }
     }
 
-    private fun <U : Data, V : Data> B<U>.i(v: V): Int {
-        return t.x + u.x + v.x
-    }
+    private fun <U : Data, V : Data> B<U>.i(v: V) = t.x + u.x + v.x
 }

idea/testData/refactoring/extractFunction/typeParameters/typeParametersCombined3.kt.after

@@ -9,8 +9,6 @@ class A<T: Data>(val t: T) {
             return i(v)
         }
 
-        private fun <V : Data> i(v: V): Int {
-            return t.x + u.x + v.x
-        }
+        private fun <V : Data> i(v: V) = t.x + u.x + v.x
     }
 }

idea/testData/refactoring/extractFunction/typeParameters/typeParametersCombinedAndThis.kt.after

@@ -12,6 +12,4 @@ class A<T: Data>(val t: T) where T: DataEx {
     }
 }
 
-private fun <T : Data, V : Data> A<T>.i(v: V): Int where T : DataEx {
-    return t.x + v.x
-}
+private fun <T : Data, V : Data> A<T>.i(v: V) where T : DataEx = t.x + v.x