[kotlin] Add "'StringBuilder.append(CharArray, offset, len)' call on the JVM" inspection

^KTIJ-22712 Fixed closes https://github.com/JetBrains/intellij-community/pull/2152 GitOrigin-RevId: e8762a92a3f18685e91bb7aa007ccf731266f239
2026-09-27 10:03:11 +07:00 · 2022-09-10 13:07:22 +00:00
parent be952fc946
commit 266b0d7e7d
14 changed files with 189 additions and 0 deletions
@@ -2496,3 +2496,5 @@ inspection.message.sealed.object.can.be.converted.to.data.object='sealed' sub-ob
 serializable.object.must.be.marked.with.data=Serializable 'object' must be marked with 'data' to properly support serialization
 convert.to.data.object=Convert to 'data object' (may change semantic)
 inspection.convert.object.to.data.object.display.name=Convert 'object' to 'data object'
+
+inspection.replace.with.string.builder.append.range.display.name='StringBuilder.append(CharArray, offset, len)' call on the JVM
@@ -0,0 +1,22 @@
+<html>
+<body>
+Reports a <code>StringBuilder.append(CharArray, offset, len)</code> function call on the JVM platform that should be replaced with a <code>StringBuilder.appendRange(CharArray, startIndex, endIndex)</code> function call.
+<p>The <code>append</code> function behaves differently on the JVM, JS and Native platforms, so using the <code>appendRange</code> function is recommended.</p>
+<p><b>Example:</b></p>
+<pre><code>
+  fun f(charArray: CharArray, offset: Int, len: Int): String {
+      return buildString {
+          append(charArray, offset, len)
+      }
+  }
+</code></pre>
+<p>After the quick-fix is applied:</p>
+<pre><code>
+  fun f(charArray: CharArray, offset: Int, len: Int): String {
+      return buildString {
+          appendRange(charArray, offset, offset + len)
+      }
+  }
+</code></pre>
+</body>
+</html>
@@ -0,0 +1,77 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.idea.inspections
+
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
+import org.jetbrains.kotlin.idea.base.facet.platform.platform
+import org.jetbrains.kotlin.idea.base.resources.KotlinBundle
+import org.jetbrains.kotlin.idea.caches.resolve.resolveToCall
+import org.jetbrains.kotlin.idea.codeinsight.api.classic.inspections.AbstractKotlinInspection
+import org.jetbrains.kotlin.idea.refactoring.fqName.fqName
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.platform.jvm.isJvm
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.types.typeUtil.isInt
+
+class ReplaceWithStringBuilderAppendRangeInspection : AbstractKotlinInspection() {
+    companion object {
+        private const val appendFunctionName = "append"
+        private const val appendRangeFunctionName = "appendRange"
+        private val appendFunctionFqName = FqName("java.lang.StringBuilder.append")
+        private val charArrayFqName = FqName("kotlin.CharArray")
+    }
+
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): KtVisitorVoid =
+        callExpressionVisitor(fun(callExpression: KtCallExpression) {
+            if (!callExpression.platform.isJvm()) return
+            val calleeExpression = callExpression.calleeExpression ?: return
+            if (calleeExpression.text != appendFunctionName) return
+            if (callExpression.valueArguments.size != 3) return
+
+            val descriptor = callExpression.resolveToCall()?.resultingDescriptor ?: return
+            if (descriptor.fqNameSafe != appendFunctionFqName) return
+
+            val params = descriptor.valueParameters
+            if (params.size != 3 || !params[0].isCharArray() || !params[1].isInt() || !params[2].isInt()) return
+
+            holder.registerProblem(
+                calleeExpression,
+                KotlinBundle.message("replace.with.0", appendRangeFunctionName),
+                ReplaceFix(appendRangeFunctionName)
+            )
+        })
+
+    private fun ValueParameterDescriptor.isCharArray(): Boolean = type.fqName == charArrayFqName
+
+    private fun ValueParameterDescriptor.isInt(): Boolean = type.isInt()
+
+    private class ReplaceFix(private val functionName: String) : LocalQuickFix {
+        override fun getName(): String = KotlinBundle.message("replace.with.0", functionName)
+
+        override fun getFamilyName(): String = name
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            val calleeExpression = descriptor.psiElement as? KtExpression ?: return
+            val callExpression = calleeExpression.parent as? KtCallExpression ?: return
+
+            val args = callExpression.valueArguments
+            val secondArg = args.getOrNull(1)?.getArgumentExpression() ?: return
+            val thirdArg = args.getOrNull(2)?.getArgumentExpression() ?: return
+
+            val psiFactory = KtPsiFactory(callExpression)
+            calleeExpression.replace(psiFactory.createCalleeExpression(functionName))
+            if (secondArg is KtConstantExpression && thirdArg is KtConstantExpression) {
+                thirdArg.replace(psiFactory.createExpression(secondArg.text.toInt().plus(thirdArg.text.toInt()).toString()))
+            } else {
+                thirdArg.replace(psiFactory.createExpressionByPattern("$0 + $1", secondArg, thirdArg))
+            }
+        }
+
+        private fun KtPsiFactory.createCalleeExpression(functionName: String): KtExpression =
+            (createExpression("$functionName()") as KtCallExpression).calleeExpression!!
+    }
+}
@@ -13277,6 +13277,34 @@ public abstract class LocalInspectionTestGenerated extends AbstractLocalInspecti
        }
    }

+    @RunWith(JUnit3RunnerWithInners.class)
+    @TestMetadata("testData/inspectionsLocal/replaceWithStringBuilderAppendRange")
+    public static class ReplaceWithStringBuilderAppendRange extends AbstractLocalInspectionTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+        }
+
+        @TestMetadata("constantArgument.kt")
+        public void testConstantArgument() throws Exception {
+            runTest("testData/inspectionsLocal/replaceWithStringBuilderAppendRange/constantArgument.kt");
+        }
+
+        @TestMetadata("hasReceiver.kt")
+        public void testHasReceiver() throws Exception {
+            runTest("testData/inspectionsLocal/replaceWithStringBuilderAppendRange/hasReceiver.kt");
+        }
+
+        @TestMetadata("precedence.kt")
+        public void testPrecedence() throws Exception {
+            runTest("testData/inspectionsLocal/replaceWithStringBuilderAppendRange/precedence.kt");
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            runTest("testData/inspectionsLocal/replaceWithStringBuilderAppendRange/simple.kt");
+        }
+    }
+
    @RunWith(JUnit3RunnerWithInners.class)
    @TestMetadata("testData/inspectionsLocal/restrictReturnStatementTargetMigration")
    public static class RestrictReturnStatementTargetMigration extends AbstractLocalInspectionTest {
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.ReplaceWithStringBuilderAppendRangeInspection
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray): String {
+    return buildString {
+        <caret>append(charArray, 2, 4)
+    }
+}
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray): String {
+    return buildString {
+        appendRange(charArray, 2, 6)
+    }
+}
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray, offset: Int, len: Int): String {
+    return buildString {
+        this.append<caret>(charArray, offset, len)
+    }
+}
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray, offset: Int, len: Int): String {
+    return buildString {
+        this.appendRange(charArray, offset, offset + len)
+    }
+}
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray, a: Int, b: Int, c: Int, d: Int): String {
+    return buildString {
+        <caret>append(charArray, a - b, c - d)
+    }
+}
@@ -0,0 +1,6 @@
+// WITH_STDLIB
+fun test(charArray: CharArray, a: Int, b: Int, c: Int, d: Int): String {
+    return buildString {
+        appendRange(charArray, a - b, a - b + (c - d))
+    }
+}
@@ -0,0 +1,7 @@
+// FIX: Replace with 'appendRange'
+// WITH_STDLIB
+fun test(charArray: CharArray, offset: Int, len: Int): String {
+    return buildString {
+        <caret>append(charArray, offset, len)
+    }
+}
@@ -0,0 +1,7 @@
+// FIX: Replace with 'appendRange'
+// WITH_STDLIB
+fun test(charArray: CharArray, offset: Int, len: Int): String {
+    return buildString {
+        appendRange(charArray, offset, offset + len)
+    }
+}
@@ -2914,6 +2914,15 @@
                     level="WEAK WARNING"
                     language="kotlin"
                     key="inspection.replace.readline.with.readln.display.name" bundle="messages.KotlinBundle"/>
+
+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.ReplaceWithStringBuilderAppendRangeInspection"
+                     groupPath="Kotlin"
+                     groupBundle="messages.KotlinBundle" groupKey="group.names.other.problems"
+                     enabledByDefault="true"
+                     level="WARNING"
+                     language="kotlin"
+                     key="inspection.replace.with.string.builder.append.range.display.name" bundle="messages.KotlinBundle"/>
+
  </extensions>

 </idea-plugin>
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.ReplaceWithStringBuilderAppendRangeInspection`