KT-20883: Add more details to MissingDocumentationInspection message

#KT-20883 fixed

idea/src/META-INF/plugin.xml

@@ -1869,7 +1869,7 @@
                      language="kotlin"
     />
 
-    <localInspection implementationClass="org.jetbrains.kotlin.idea.kdoc.KDocMissingDocumentationInspection"
+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.kdoc.KDocMissingDocumentationInspection"
                      displayName="Missing KDoc comments for public declarations"
                      groupPath="Kotlin"
                      groupName="Other problems"

idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt

@@ -138,17 +138,7 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
         return object : KtVisitorVoid() {
             override fun visitDeclaration(declaration: KtDeclaration) {
                 if (declaration !is KtNamedDeclaration) return
-                val name = declaration.name ?: return
-                val message = when (declaration) {
-                    is KtClass -> "Class ''$name'' is never used"
-                    is KtObjectDeclaration -> "Object ''$name'' is never used"
-                    is KtNamedFunction -> "Function ''$name'' is never used"
-                    is KtSecondaryConstructor -> "Constructor is never used"
-                    is KtProperty, is KtParameter -> "Property ''$name'' is never used"
-                    is KtTypeParameter -> "Type parameter ''$name'' is never used"
-                    is KtTypeAlias -> "Type alias ''$name'' is never used"
-                    else -> return
-                }
+                val message = declaration.describe()?.let { "$it is never used" } ?: return
 
                 if (!ProjectRootsUtil.isInProjectSource(declaration)) return
 

idea/src/org/jetbrains/kotlin/idea/inspections/describeDeclaration.kt

@@ -0,0 +1,33 @@
+/*
+ * 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
+
+import org.jetbrains.kotlin.psi.*
+
+/**
+ * @returns string description of declaration, like Function ''name''
+ */
+fun KtNamedDeclaration.describe(): String? = when (this) {
+    is KtClass -> "Class ''$name''"
+    is KtObjectDeclaration -> "Object ''$name''"
+    is KtNamedFunction -> "Function ''$name''"
+    is KtSecondaryConstructor -> "Constructor"
+    is KtProperty, is KtParameter -> "Property ''$name''"
+    is KtTypeParameter -> "Type parameter ''$name''"
+    is KtTypeAlias -> "Type alias ''$name''"
+    else -> null
+}

idea/src/org/jetbrains/kotlin/idea/inspections/kdoc/KDocMissingDocumentationInspection.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
+ * 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.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.idea.kdoc
+package org.jetbrains.kotlin.idea.inspections.kdoc
 
 import com.intellij.codeInsight.FileModificationService
 import com.intellij.codeInspection.LocalQuickFix
@@ -30,7 +30,9 @@ import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
 import org.jetbrains.kotlin.idea.core.unblockDocument
 import org.jetbrains.kotlin.idea.inspections.AbstractKotlinInspection
+import org.jetbrains.kotlin.idea.inspections.describe
 import org.jetbrains.kotlin.idea.inspections.findExistingEditor
+import org.jetbrains.kotlin.idea.kdoc.KDocElementFactory
 import org.jetbrains.kotlin.kdoc.psi.impl.KDocSection
 import org.jetbrains.kotlin.psi.KtNamedDeclaration
 import org.jetbrains.kotlin.psi.KtPsiFactory
@@ -55,7 +57,8 @@ class KDocMissingDocumentationInspection() : AbstractKotlinInspection() {
                                            (descriptor as? CallableMemberDescriptor)?.overriddenDescriptors
                                                    ?.any { (it.source.getPsi() as? KtNamedDeclaration)?.docComment != null } ?: false
                     if (!hasDocumentation) {
-                        holder.registerProblem(nameIdentifier, "Missing documentation", AddDocumentationFix())
+                        val message = element.describe()?.let { "$it is missing documentation" } ?: "Missing documentation"
+                        holder.registerProblem(nameIdentifier, message, AddDocumentationFix())
                     }
                 }
             }

idea/testData/inspectionsLocal/kdocMissingDocumentation/.inspection

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.kdoc.KDocMissingDocumentationInspection

idea/testData/inspectionsLocal/kdocMissingDocumentation/simple.kt

@@ -0,0 +1,3 @@
+// PROBLEM: "Class ''A'' is missing documentation"
+
+class <caret>A

idea/testData/inspectionsLocal/kdocMissingDocumentation/simple.kt.after

@@ -0,0 +1,6 @@
+// PROBLEM: "Class ''A'' is missing documentation"
+
+/**
+ * <caret>
+ */
+class A

idea/testData/quickfix/kdocMissingDocumentation/.inspection

@@ -1 +1 @@
-org.jetbrains.kotlin.idea.kdoc.KDocMissingDocumentationInspection
+org.jetbrains.kotlin.idea.inspections.kdoc.KDocMissingDocumentationInspection

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -582,6 +582,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         }
     }
 
+    @TestMetadata("idea/testData/inspectionsLocal/kdocMissingDocumentation")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class KdocMissingDocumentation extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInKdocMissingDocumentation() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/kdocMissingDocumentation"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/kdocMissingDocumentation/simple.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/inspectionsLocal/leakingThis")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

idea/tests/org/jetbrains/kotlin/idea/kdoc/AbstractKDocHighlightingTest.java

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.idea.kdoc;
 
 import org.jetbrains.kotlin.idea.highlighter.AbstractHighlightingTest;
+import org.jetbrains.kotlin.idea.inspections.kdoc.KDocMissingDocumentationInspection;
 
 public abstract class AbstractKDocHighlightingTest extends AbstractHighlightingTest {
     @Override