Support implicit receiver in if-then intentions #KT-16069 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/ReplaceSubstringIntention.kt

@@ -19,7 +19,7 @@ package org.jetbrains.kotlin.idea.intentions
 import com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.evaluatesTo
-import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator
@@ -30,7 +30,7 @@ abstract class ReplaceSubstringIntention(text: String) : SelfTargetingRangeInten
     protected abstract fun applicabilityRangeInner(element: KtDotQualifiedExpression): TextRange?
 
     override fun applicabilityRange(element: KtDotQualifiedExpression): TextRange? {
-        if (element.receiverExpression.isStableVariable() && element.isMethodCall("kotlin.text.substring")) {
+        if (element.receiverExpression.isStable() && element.isMethodCall("kotlin.text.substring")) {
             return applicabilityRangeInner(element)
         }
         return null

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/IfThenUtils.kt

@@ -34,7 +34,9 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingContextUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.calls.callUtil.getType
+import org.jetbrains.kotlin.resolve.calls.resolvedCallUtil.getImplicitReceiverValue
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.TypeUtils
@@ -140,7 +142,8 @@ fun KtPostfixExpression.inlineBaseExpressionIfApplicableWithPrompt(editor: Edito
     (this.baseExpression as? KtNameReferenceExpression)?.inlineIfDeclaredLocallyAndOnlyUsedOnceWithPrompt(editor)
 }
 
-fun KtExpression.isStableVariable(context: BindingContext = this.analyze()): Boolean {
+fun KtExpression.isStable(context: BindingContext = this.analyze()): Boolean {
+    if (this is KtConstantExpression || this is KtThisExpression) return true
     val descriptor = BindingContextUtils.extractVariableDescriptorFromReference(context, this)
     return descriptor is VariableDescriptor &&
            DataFlowValueFactory.isStableValue(descriptor, DescriptorUtils.getContainingModule(descriptor))
@@ -168,11 +171,17 @@ data class IfThenToSelectData(
                 (baseClause as KtDotQualifiedExpression).replaceFirstReceiver(
                         factory, newReceiver!!, safeAccess = true)
             }
-            else {
+            else if (hasImplicitReceiver()) {
+                factory.createExpressionByPattern("this?.$0", baseClause).insertSafeCalls(factory)
+            } else {
                 baseClause.insertSafeCalls(factory)
             }
         }
     }
+
+    internal fun hasImplicitReceiver(): Boolean {
+        return baseClause.getResolvedCall(context)?.getImplicitReceiverValue() != null
+    }
 }
 
 internal fun KtIfExpression.buildSelectTransformationData(): IfThenToSelectData? {
@@ -199,7 +208,6 @@ internal fun KtIfExpression.buildSelectTransformationData(): IfThenToSelectData?
             when (condition.isNegated) {
                 true -> elseClause to thenClause
                 false -> thenClause to elseClause
-                else -> return null
             }
         }
         else -> return null

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/DoubleBangToIfThenIntention.kt

@@ -31,7 +31,7 @@ import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.convertToIfNotNullExpression
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.convertToIfNullExpression
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.introduceValueForCondition
-import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtPostfixExpression
 import org.jetbrains.kotlin.psi.KtPsiFactory
@@ -56,7 +56,7 @@ class DoubleBangToIfThenIntention : SelfTargetingRangeIntention<KtPostfixExpress
         val defaultException = KtPsiFactory(element).createExpression("throw NullPointerException()")
 
         val isStatement = element.isUsedAsStatement(element.analyze())
-        val isStable = base.isStableVariable()
+        val isStable = base.isStable()
 
         val ifStatement = if (isStatement)
             element.convertToIfNullExpression(base, defaultException)

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/ElvisToIfThenIntention.kt

@@ -22,7 +22,7 @@ import com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.convertToIfNotNullExpression
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.introduceValueForCondition
-import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtBinaryExpression
 import org.jetbrains.kotlin.psi.KtPsiUtil
@@ -39,7 +39,7 @@ class ElvisToIfThenIntention : SelfTargetingRangeIntention<KtBinaryExpression>(K
         val left = KtPsiUtil.safeDeparenthesize(element.left!!)
         val right = KtPsiUtil.safeDeparenthesize(element.right!!)
 
-        val leftIsStable = left.isStableVariable()
+        val leftIsStable = left.isStable()
 
         val ifStatement = element.convertToIfNotNullExpression(left, left, right)
 

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToDoubleBangIntention.kt

@@ -38,7 +38,7 @@ class IfThenToDoubleBangIntention : SelfTargetingRangeIntention<KtIfExpression>(
 
         val matchesAsStatement = element.isUsedAsStatement(context) && (baseClause?.isNullExpressionOrEmptyBlock() ?: true)
         if (!matchesAsStatement &&
-            !(baseClause?.evaluatesTo(receiverExpression) ?: false && receiverExpression.isStableVariable())) return null
+            !(baseClause?.evaluatesTo(receiverExpression) ?: false && receiverExpression.isStable())) return null
 
         var text = "Replace 'if' expression with '!!' expression"
         if (!throwExpression.throwsNullPointerExceptionWithNoArguments()) {

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt

@@ -49,13 +49,15 @@ class IfThenToElvisIntention : SelfTargetingOffsetIndependentIntention<KtIfExpre
     private fun IfThenToSelectData.clausesReplaceableByElvis(): Boolean {
         if (baseClause == null || negatedClause == null || negatedClause.isNullOrBlockExpression()) return false
         if (negatedClause is KtThrowExpression && negatedClause.throwsNullPointerExceptionWithNoArguments()) return false
-        return baseClause.evaluatesTo(receiverExpression) ||
+
+        return receiverExpression is KtThisExpression && hasImplicitReceiver() ||
+               baseClause.evaluatesTo(receiverExpression) ||
                baseClause.hasFirstReceiverOf(receiverExpression) && !baseClause.hasNullableType(context)
     }
 
     override fun isApplicableTo(element: KtIfExpression): Boolean {
         val ifThenToSelectData = element.buildSelectTransformationData() ?: return false
-        if (!ifThenToSelectData.receiverExpression.isStableVariable(ifThenToSelectData.context)) return false
+        if (!ifThenToSelectData.receiverExpression.isStable(ifThenToSelectData.context)) return false
 
         val type = element.getType(ifThenToSelectData.context) ?: return false
         if (KotlinBuiltIns.isUnit(type)) return false

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToSafeAccessIntention.kt

@@ -39,7 +39,7 @@ class IfThenToSafeAccessIntention : SelfTargetingOffsetIndependentIntention<KtIf
 
     override fun isApplicableTo(element: KtIfExpression): Boolean {
         val ifThenToSelectData = element.buildSelectTransformationData() ?: return false
-        if (!ifThenToSelectData.receiverExpression.isStableVariable(ifThenToSelectData.context)) return false
+        if (!ifThenToSelectData.receiverExpression.isStable(ifThenToSelectData.context)) return false
         if (ifThenToSelectData.baseClause !is KtDotQualifiedExpression) {
             if (ifThenToSelectData.condition is KtIsExpression) {
                 text = "Replace 'if' expression with safe cast expression"
@@ -73,6 +73,7 @@ class IfThenToSafeAccessIntention : SelfTargetingOffsetIndependentIntention<KtIf
         baseClause == null -> false
         negatedClause == null && baseClause.isUsedAsExpression(context) -> false
         negatedClause != null && !negatedClause.isNullExpression() -> false
-        else -> baseClause.evaluatesTo(receiverExpression) || baseClause.hasFirstReceiverOf(receiverExpression)
+        else -> baseClause.evaluatesTo(receiverExpression) || baseClause.hasFirstReceiverOf(receiverExpression) ||
+                receiverExpression is KtThisExpression && hasImplicitReceiver()
     }
 }

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/MergeWhenIntention.kt

@@ -23,7 +23,7 @@ import com.intellij.psi.util.PsiTreeUtil
 import org.jetbrains.kotlin.idea.core.appendElement
 import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
-import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.matches
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.toRange
 import org.jetbrains.kotlin.psi.*
@@ -36,7 +36,7 @@ class MergeWhenIntention : SelfTargetingRangeIntention<KtWhenExpression>(KtWhenE
         val subject1 = element.subjectExpression
         val subject2 = next.subjectExpression
         if (!subject1.matches(subject2)) return null
-        if (subject1 != null && !subject1.isStableVariable()) return null
+        if (subject1 != null && !subject1.isStable()) return null
 
         val entries1 = element.entries
         val entries2 = next.entries

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/SafeAccessToIfThenIntention.kt

@@ -23,7 +23,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.convertToIfNotNullExpression
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.introduceValueForCondition
-import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsStatement
 
@@ -37,7 +37,7 @@ class SafeAccessToIfThenIntention : SelfTargetingRangeIntention<KtSafeQualifiedE
         val receiver = KtPsiUtil.safeDeparenthesize(element.receiverExpression)
         val selector = element.selectorExpression!!
 
-        val receiverIsStable = receiver.isStableVariable()
+        val receiverIsStable = receiver.isStable()
 
         val psiFactory = KtPsiFactory(element)
         val dotQualified = psiFactory.createExpressionByPattern("$0.$1", receiver, selector)

idea/src/org/jetbrains/kotlin/idea/quickfix/SurroundWithNullCheckFix.kt

@@ -23,17 +23,13 @@ import com.intellij.openapi.project.Project
 import org.jetbrains.kotlin.diagnostics.Diagnostic
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
-import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isStable
-import org.jetbrains.kotlin.idea.util.getResolutionScope
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.createSmartPointer
 import org.jetbrains.kotlin.psi.psiUtil.getLastParentOfTypeInRow
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfTypesAndPredicate
-import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsExpression
-import org.jetbrains.kotlin.resolve.calls.callUtil.getType
-import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.typeUtil.isNullabilityMismatch
 
@@ -120,9 +116,3 @@ class SurroundWithNullCheckFix(
         }
     }
 }
-
-private fun KtExpression.isStable(context: BindingContext = this.analyze()): Boolean {
-    val nullableType = this.getType(context) ?: return false
-    val containingDescriptor = this.getResolutionScope(context, this.getResolutionFacade()).ownerDescriptor
-    return DataFlowValueFactory.createDataFlowValue(this, nullableType, context, containingDescriptor).isStable
-}

idea/testData/intentions/branched/ifThenToDoubleBang/this.kt

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = if (this == <caret>null) throw NullPointerException() else this

idea/testData/intentions/branched/ifThenToDoubleBang/this.kt.after

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = this!!

idea/testData/intentions/branched/ifThenToElvis/implicitReceiver.kt

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = <caret>if (this == null) true else isEmpty()

idea/testData/intentions/branched/ifThenToElvis/implicitReceiver.kt.after

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = this?.isEmpty() ?: true

idea/testData/intentions/branched/ifThenToElvis/inspectionData/expected.xml

@@ -95,4 +95,12 @@
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
     <description>Replace 'if' expression with elvis expression</description>
   </problem>
+  <problem>
+    <file>implicitReceiver.kt</file>
+    <line>2</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/implicitReceiver.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>Replace 'if' expression with elvis expression</description>
+  </problem>
 </problems>

idea/testData/intentions/branched/ifThenToSafeAccess/implicitReceiver.kt

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = <caret>if (this == null) null else isEmpty()

idea/testData/intentions/branched/ifThenToSafeAccess/implicitReceiver.kt.after

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = this?.isEmpty()

idea/testData/intentions/branched/ifThenToSafeAccess/inspectionData/expected.xml

@@ -143,4 +143,12 @@
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?.'</problem_class>
     <description>Remove redundant 'if' expression</description>
   </problem>
+  <problem>
+    <file>implicitReceiver.kt</file>
+    <line>2</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/implicitReceiver.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?.'</problem_class>
+    <description>Remove redundant 'if' expression</description>
+  </problem>
 </problems>

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -1381,6 +1381,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("this.kt")
+            public void testThis() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToDoubleBang/this.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("throwByFqName.kt")
             public void testThrowByFqName() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToDoubleBang/throwByFqName.kt");
@@ -1510,6 +1516,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("implicitReceiver.kt")
+            public void testImplicitReceiver() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/implicitReceiver.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("isCheck.kt")
             public void testIsCheck() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToElvis/isCheck.kt");
@@ -1765,6 +1777,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("implicitReceiver.kt")
+            public void testImplicitReceiver() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToSafeAccess/implicitReceiver.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("isCheckSimple.kt")
             public void testIsCheckSimple() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/branched/ifThenToSafeAccess/isCheckSimple.kt");