Remove redundant let in "Safe access to if-then" #KT-13515 Fixed

2018-07-25 12:27:38 +03:00
parent 443b1834bc
commit 7e8521d9dc
12 changed files with 122 additions and 7 deletions
@@ -21,16 +21,24 @@ import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.core.replaced
+import org.jetbrains.kotlin.idea.intentions.ReplaceSingleLineLetIntention
 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.isStableSimpleExpression
+import org.jetbrains.kotlin.idea.intentions.callExpression
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.collectDescendantsOfType
 import org.jetbrains.kotlin.psi.psiUtil.findDescendantOfType
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsStatement
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode

-class SafeAccessToIfThenIntention : SelfTargetingRangeIntention<KtSafeQualifiedExpression>(KtSafeQualifiedExpression::class.java, "Replace safe access expression with 'if' expression"), LowPriorityAction {
+class SafeAccessToIfThenIntention : SelfTargetingRangeIntention<KtSafeQualifiedExpression>(
+    KtSafeQualifiedExpression::class.java,
+    "Replace safe access expression with 'if' expression"
+), LowPriorityAction {
    override fun applicabilityRange(element: KtSafeQualifiedExpression): TextRange? {
        if (element.selectorExpression == null) return null
        return element.operationTokenNode.textRange
@@ -57,14 +65,33 @@ class SafeAccessToIfThenIntention : SelfTargetingRangeIntention<KtSafeQualifiedE
            isAssignment = true
        }

-        if (!receiverIsStable) {
-            val valueToExtract = if (isAssignment)
-                ((ifExpression.then as? KtBinaryExpression)?.left as? KtDotQualifiedExpression)?.receiverExpression
-            else
-                (ifExpression.then as? KtDotQualifiedExpression)?.receiverExpression
+        val isRedundantLetCallRemoved = ifExpression.removeRedundantLetCallIfPossible(editor)

+        if (!receiverIsStable) {
+            val valueToExtract = when {
+                isAssignment ->
+                    ((ifExpression.then as? KtBinaryExpression)?.left as? KtDotQualifiedExpression)?.receiverExpression
+                isRedundantLetCallRemoved -> {
+                    val context = ifExpression.analyze(BodyResolveMode.PARTIAL)
+                    val descriptor = (ifExpression.condition as? KtBinaryExpression)?.left?.getResolvedCall(context)?.resultingDescriptor
+                    ifExpression.then?.findDescendantOfType<KtNameReferenceExpression> {
+                        it.getReferencedNameAsName() == descriptor?.name && it.getResolvedCall(context)?.resultingDescriptor == descriptor
+                    }
+                }
+                else ->
+                    (ifExpression.then as? KtDotQualifiedExpression)?.receiverExpression
+            }
            if (valueToExtract != null) ifExpression.introduceValueForCondition(valueToExtract, editor)
        }
-
    }
+
+    private fun KtIfExpression.removeRedundantLetCallIfPossible(editor: Editor?): Boolean {
+        val callExpression = (then as? KtQualifiedExpression)?.callExpression ?: return false
+        if (callExpression.calleeExpression?.text != "let") return false
+        val replaceSingleLineLetIntention = ReplaceSingleLineLetIntention()
+        if (!replaceSingleLineLetIntention.isApplicableTo(callExpression)) return false
+        replaceSingleLineLetIntention.applyTo(callExpression, editor)
+        return true
+    }
+
 }
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return value<caret>?.let { it + 1 }
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return if (value != null) value + 1 else null
+}
@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return value<caret>?.let { baz(it) }
+}
+
+fun baz(i: Int) = i + i
@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return if (value != null) baz(value) else null
+}
+
+fun baz(i: Int) = i + i
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun foo(a: Int, b: Int?): Int? {
+    return b<caret>?.let { a + b }
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun foo(a: Int, b: Int?): Int? {
+    return if (b != null) b.let { a + b } else null
+}
@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return value<caret>?.let {
+        println()
+        it + 1
+    }
+}
@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+
+fun foo(value: Int?): Int? {
+    return if (value != null) value.let {
+        println()
+        it + 1
+    } else null
+}
@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+
+var a: String? = "A"
+fun main(args: Array<String>) {
+    a<caret>?.let { it.length + 1 }
+}
@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+var a: String? = "A"
+fun main(args: Array<String>) {
+    val a1 = a
+    if (a1 != null) a1.length + 1
+}
@@ -2796,6 +2796,31 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                runTest("idea/testData/intentions/branched/safeAccessToIfThen/equality.kt");
            }

+            @TestMetadata("let.kt")
+            public void testLet() throws Exception {
+                runTest("idea/testData/intentions/branched/safeAccessToIfThen/let.kt");
+            }
+
+            @TestMetadata("let2.kt")
+            public void testLet2() throws Exception {
+                runTest("idea/testData/intentions/branched/safeAccessToIfThen/let2.kt");
+            }
+
+            @TestMetadata("let3.kt")
+            public void testLet3() throws Exception {
+                runTest("idea/testData/intentions/branched/safeAccessToIfThen/let3.kt");
+            }
+
+            @TestMetadata("letNotRedundant.kt")
+            public void testLetNotRedundant() throws Exception {
+                runTest("idea/testData/intentions/branched/safeAccessToIfThen/letNotRedundant.kt");
+            }
+
+            @TestMetadata("letTopLevelVar.kt")
+            public void testLetTopLevelVar() throws Exception {
+                runTest("idea/testData/intentions/branched/safeAccessToIfThen/letTopLevelVar.kt");
+            }
+
            @TestMetadata("localValAsReceiver.kt")
            public void testLocalValAsReceiver() throws Exception {
                runTest("idea/testData/intentions/branched/safeAccessToIfThen/localValAsReceiver.kt");