Fix unavailable 'Specify visibility explicitly' quickfix

in explicit API mode due to incorrect cast.
Add tests for applying this quickfix.
#KT-36020 fixed.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -14,13 +14,14 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithVisibility
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.diagnostics.Diagnostic
-import org.jetbrains.kotlin.diagnostics.DiagnosticFactory1
+import org.jetbrains.kotlin.diagnostics.DiagnosticFactory0
 import org.jetbrains.kotlin.idea.core.canBeInternal
 import org.jetbrains.kotlin.idea.core.canBePrivate
 import org.jetbrains.kotlin.idea.core.canBeProtected
 import org.jetbrains.kotlin.idea.core.setVisibility
 import org.jetbrains.kotlin.idea.inspections.RemoveRedundantSetterFix
 import org.jetbrains.kotlin.idea.inspections.isRedundantSetter
+import org.jetbrains.kotlin.idea.search.usagesSearch.descriptor
 import org.jetbrains.kotlin.idea.util.runOnExpectAndAllActuals
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
@@ -121,8 +122,8 @@ open class ChangeVisibilityFix(
     object SetExplicitVisibilityFactory : KotlinIntentionActionsFactory() {
         @Suppress("UNCHECKED_CAST")
         override fun doCreateActions(diagnostic: Diagnostic): List<IntentionAction> {
-            val factory = diagnostic.factory as DiagnosticFactory1<*, DeclarationDescriptor>
+            val factory = diagnostic.factory as DiagnosticFactory0<KtDeclaration>
-            val descriptor = factory.cast(diagnostic).a as? DeclarationDescriptorWithVisibility ?: return emptyList()
+            val descriptor = factory.cast(diagnostic).psiElement.descriptor as? DeclarationDescriptorWithVisibility ?: return emptyList()
             val element = diagnostic.psiElement as? KtModifierListOwner ?: return emptyList()
             return listOf(
                 ChangeToPublicExplicitlyFix(

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/class.kt

@@ -0,0 +1,5 @@
+// "Make 'Foo1' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+class <caret>Foo1() {}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/class.kt.after

@@ -0,0 +1,5 @@
+// "Make 'Foo1' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo1() {}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/companion.kt

@@ -0,0 +1,7 @@
+// "Make 'Companion' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo1() {
+    companion <caret>object {}
+}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/companion.kt.after

@@ -0,0 +1,7 @@
+// "Make 'Companion' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo1() {
+    public companion object {}
+}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/constructor.kt

@@ -0,0 +1,7 @@
+// "Make '<init>' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo5 {
+    constructor<caret>() {}
+}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/constructor.kt.after

@@ -0,0 +1,7 @@
+// "Make '<init>' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo5 {
+    public constructor() {}
+}
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/method.kt

@@ -0,0 +1,6 @@
+// "Make 'method' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo2() {
+    fun <caret>method() {}
+}

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/method.kt.after

@@ -0,0 +1,6 @@
+// "Make 'method' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo2() {
+    public fun method() {}
+}

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/property.kt

@@ -0,0 +1,5 @@
+// "Make 'bar' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo(val <caret>bar: Int, private var bar2: String, internal var bar3: Long, public var bar4: Int)
+

idea/testData/quickfix/specifyVisibilityInExplicitApiMode/property.kt.after

@@ -0,0 +1,5 @@
+// "Make 'bar' public explicitly" "true"
+// COMPILER_ARGUMENTS: -Xexplicit-api=strict
+
+public class Foo(public val bar: Int, private var bar2: String, internal var bar3: Long, public var bar4: Int)
+

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiFileTestGenerated.java

@@ -4148,6 +4148,19 @@ public class QuickFixMultiFileTestGenerated extends AbstractQuickFixMultiFileTes
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/specifyVisibilityInExplicitApiMode")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class SpecifyVisibilityInExplicitApiMode extends AbstractQuickFixMultiFileTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTestWithExtraFile, this, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInSpecifyVisibilityInExplicitApiMode() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/quickfix/specifyVisibilityInExplicitApiMode"), Pattern.compile("^(\\w+)\\.((before\\.Main\\.\\w+)|(test))$"), null, true);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/superTypeIsExtensionType")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -11683,6 +11683,44 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/specifyVisibilityInExplicitApiMode")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class SpecifyVisibilityInExplicitApiMode extends AbstractQuickFixTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInSpecifyVisibilityInExplicitApiMode() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/quickfix/specifyVisibilityInExplicitApiMode"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), null, true);
+        }
+
+        @TestMetadata("class.kt")
+        public void testClass() throws Exception {
+            runTest("idea/testData/quickfix/specifyVisibilityInExplicitApiMode/class.kt");
+        }
+
+        @TestMetadata("companion.kt")
+        public void testCompanion() throws Exception {
+            runTest("idea/testData/quickfix/specifyVisibilityInExplicitApiMode/companion.kt");
+        }
+
+        @TestMetadata("constructor.kt")
+        public void testConstructor() throws Exception {
+            runTest("idea/testData/quickfix/specifyVisibilityInExplicitApiMode/constructor.kt");
+        }
+
+        @TestMetadata("method.kt")
+        public void testMethod() throws Exception {
+            runTest("idea/testData/quickfix/specifyVisibilityInExplicitApiMode/method.kt");
+        }
+
+        @TestMetadata("property.kt")
+        public void testProperty() throws Exception {
+            runTest("idea/testData/quickfix/specifyVisibilityInExplicitApiMode/property.kt");
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/superTypeIsExtensionType")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)