Introduce "Useless call on not-null type" inspection #KT-18386 Fixed

Supported functions: orEmpty(), isNullOrEmpty(), isNullOrBlank()
2017-06-16 17:14:59 +03:00
parent 8c21ff66a4
commit 0f4ae3b727
21 changed files with 322 additions and 0 deletions
@@ -0,0 +1,8 @@
+<html>
+<body>
+This inspection reports calls on not-null receiver that make sense only for nullable receiver, e.g.
+<pre><code>
+listOf(1).orEmpty()
+</code></pre>
+</body>
+</html>
@@ -2242,6 +2242,14 @@
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.collections.UselessCallOnNotNullInspection"
+                     displayName="Useless call on not-null type"
+                     groupName="Kotlin"
+                     enabledByDefault="true"
+                     level="WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.inspections.collections
+
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.idea.core.replaced
+import org.jetbrains.kotlin.psi.KtQualifiedExpression
+
+class RemoveUselessCallFix : LocalQuickFix {
+
+    override fun getName() = "Remove useless call"
+
+    override fun getFamilyName() = name
+
+    override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+        (descriptor.psiElement as? KtQualifiedExpression)?.let {
+            it.replaced(it.receiverExpression)
+        }
+    }
+}
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.inspections.collections
+
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.idea.core.replaced
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.psi.KtQualifiedExpression
+import org.jetbrains.kotlin.psi.KtSafeQualifiedExpression
+import org.jetbrains.kotlin.psi.createExpressionByPattern
+
+class RenameUselessCallFix(val newName: String) : LocalQuickFix {
+    override fun getName() = "Rename useless call to '$newName'"
+
+    override fun getFamilyName() = name
+
+    override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+        (descriptor.psiElement as? KtQualifiedExpression)?.let {
+            val factory = KtPsiFactory(it)
+            val sign = if (it is KtSafeQualifiedExpression) "?." else "."
+            it.replaced(factory.createExpressionByPattern("$0$sign$newName()", it.receiverExpression))
+        }
+    }
+}
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.inspections.collections
+
+import com.intellij.codeInspection.IntentionWrapper
+import com.intellij.codeInspection.ProblemHighlightType
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.openapi.util.TextRange
+import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.inspections.AbstractKotlinInspection
+import org.jetbrains.kotlin.idea.quickfix.ReplaceWithDotCallFix
+import org.jetbrains.kotlin.psi.KtCallExpression
+import org.jetbrains.kotlin.psi.KtQualifiedExpression
+import org.jetbrains.kotlin.psi.KtSafeQualifiedExpression
+import org.jetbrains.kotlin.psi.KtVisitorVoid
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
+import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.callUtil.getType
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameOrNull
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.TypeUtils
+
+class UselessCallOnNotNullInspection : AbstractKotlinInspection() {
+
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): PsiElementVisitor {
+        return object : KtVisitorVoid() {
+            override fun visitQualifiedExpression(expression: KtQualifiedExpression) {
+                super.visitQualifiedExpression(expression)
+                val selector = expression.selectorExpression as? KtCallExpression ?: return
+                val calleeExpression = selector.calleeExpression ?: return
+                if (calleeExpression.text !in names) return
+
+                val context = expression.analyze(BodyResolveMode.PARTIAL)
+                val resolvedCall = expression.getResolvedCall(context) ?: return
+                val conversion = fqNames[resolvedCall.resultingDescriptor.fqNameOrNull()?.asString()] ?: return
+                val newName = conversion.replacementName
+
+                val safeExpression = expression as? KtSafeQualifiedExpression
+                val notNullType = expression.receiverExpression.getType(context)?.let { TypeUtils.isNullableType(it) } == false
+                if (newName != null && (notNullType || safeExpression != null)) {
+                    val descriptor = holder.manager.createProblemDescriptor(
+                            expression,
+                            TextRange(expression.operationTokenNode.startOffset - expression.startOffset,
+                                      calleeExpression.endOffset - expression.startOffset),
+                            "Call on not-null type may be reduced",
+                            ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                            isOnTheFly,
+                            RenameUselessCallFix(newName)
+                    )
+                    holder.registerProblem(descriptor)
+                }
+                else if (notNullType) {
+                    val descriptor = holder.manager.createProblemDescriptor(
+                            expression,
+                            TextRange(expression.operationTokenNode.startOffset - expression.startOffset,
+                                      calleeExpression.endOffset - expression.startOffset),
+                            "Useless call on not-null type",
+                            ProblemHighlightType.LIKE_UNUSED_SYMBOL,
+                            isOnTheFly,
+                            RemoveUselessCallFix()
+                    )
+                    holder.registerProblem(descriptor)
+                }
+                else if (safeExpression != null) {
+                    holder.registerProblem(
+                            safeExpression.operationTokenNode.psi,
+                            "This call is useless with ?.",
+                            ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                            IntentionWrapper(ReplaceWithDotCallFix(safeExpression), safeExpression.containingKtFile)
+                    )
+                }
+            }
+        }
+    }
+
+    companion object {
+        private data class Conversion(val replacementName: String? = null)
+
+        private val deleteConversion = Conversion()
+
+        private val fqNames = mapOf("kotlin.collections.orEmpty" to deleteConversion,
+                                    "kotlin.text.orEmpty" to deleteConversion,
+                                    "kotlin.text.isNullOrEmpty" to Conversion("isEmpty"),
+                                    "kotlin.text.isNullOrBlank" to Conversion("isBlank"))
+
+        private val names = fqNames.keys.mapTo(mutableSetOf()) { fqName -> fqName.takeLastWhile { it != '.' } }
+    }
+}
+
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.collections.UselessCallOnNotNullInspection
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int> = listOf(1)
+val list = list1<caret>.orEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int> = listOf(1)
+val list = list1
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int> = listOf(1)
+val list = list1.<caret>orEmpty().map { "$it" }
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int> = listOf(1)
+val list = list1.map { "$it" }
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s: String? = ""
+val blank = s<caret>?.isNullOrBlank()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s: String? = ""
+val blank = s?.isBlank()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s = ""
+val empty = s<caret>.isNullOrEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s = ""
+val empty = s.isEmpty()
@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+val s: String? = null
+val empty = s<caret>.isNullOrEmpty()
@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+val list: List<String>? = null
+val empty = list<caret>.orEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int>? = listOf(1)
+val list = list1<caret>?.orEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val list1: List<Int>? = listOf(1)
+val list = list1.orEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s = ""
+val s1 = s<caret>.orEmpty()
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+val s = ""
+val s1 = s
@@ -51,6 +51,72 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/collections")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class Collections extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInCollections() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/collections"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class UselessCallOnNotNull extends AbstractLocalInspectionTest {
+            public void testAllFilesPresentInUselessCallOnNotNull() throws Exception {
+                KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+            }
+
+            @TestMetadata("NotNullType.kt")
+            public void testNotNullType() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/NotNullType.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("NotNullTypeChain.kt")
+            public void testNotNullTypeChain() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/NotNullTypeChain.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("NullOrBlankSafe.kt")
+            public void testNullOrBlankSafe() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/NullOrBlankSafe.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("NullOrEmpty.kt")
+            public void testNullOrEmpty() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/NullOrEmpty.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("NullOrEmptyFake.kt")
+            public void testNullOrEmptyFake() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/NullOrEmptyFake.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("OrEmptyFake.kt")
+            public void testOrEmptyFake() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/OrEmptyFake.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("SafeCall.kt")
+            public void testSafeCall() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/SafeCall.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("String.kt")
+            public void testString() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/collections/uselessCallOnNotNull/String.kt");
+                doTest(fileName);
+            }
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/copyWithoutNamedArguments")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.collections.UselessCallOnNotNullInspection`