Unused symbol: handling of import as alias not only for objects / enums #KT-11933 Fixed

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

@@ -244,6 +244,9 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
 
             val import = ref.element.getParentOfType<KtImportDirective>(false)
             if (import != null) {
+                if (import.aliasName != null && import.aliasName != declaration.name) {
+                    return false
+                }
                 // check if we import member(s) from object or enum and search for their usages
                 if (declaration is KtObjectDeclaration || (declaration is KtClass && declaration.isEnum())) {
                     if (import.isAllUnder) {
@@ -251,9 +254,6 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
                                                    as? KtClassOrObject ?: return true
                         return importedFrom.declarations.none { it is KtNamedDeclaration && hasNonTrivialUsages(it) }
                     }
-                    else if (import.aliasName != null && import.aliasName != declaration.name) {
-                        return false
-                    }
                     else {
                         if (import.importedFqName != declaration.fqName) {
                             val importedDeclaration = import.importedReference?.getQualifiedElementSelector()?.mainReference?.resolve() as? KtNamedDeclaration

idea/testData/quickfix/removeUnused/usedClassAsAlias.kt

@@ -0,0 +1,10 @@
+// "Safe delete 'Imported'" "false"
+// ACTION: Create test
+// ACTION: Move 'ImportedClass' to separate file
+import ImportedClass as ClassAlias
+
+class <caret>ImportedClass
+
+fun use() {
+    ClassAlias().hashCode()
+}

idea/testData/quickfix/removeUnused/usedFunAsAlias.kt

@@ -0,0 +1,11 @@
+// "Safe delete 'useMe'" "false"
+// ACTION: Convert function to property
+// ACTION: Convert to block body
+// ACTION: Create test
+// ACTION: Specify return type explicitly
+
+import useMe as used
+
+fun <caret>useMe() = 0
+
+fun foo() = used()

idea/testData/quickfix/removeUnused/usedObjectAsAliasMulti.before.Dependency.kt

@@ -0,0 +1,5 @@
+import Imported as Alias
+
+fun foo() {
+    Alias.hashCode()
+}

idea/testData/quickfix/removeUnused/usedObjectAsAliasMulti.before.Main.kt

@@ -0,0 +1,3 @@
+// "Safe delete 'Imported'" "false"
+// ACTION: Create test
+object <caret>Imported

idea/testData/quickfix/removeUnused/usedVarAsAlias.kt

@@ -0,0 +1,9 @@
+// "Safe delete 'usedVar'" "false"
+// ACTION: Specify type explicitly
+import usedVar as used
+
+var <caret>usedVar = 0
+
+fun foo() {
+    used++
+}

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

@@ -1529,6 +1529,21 @@ public class QuickFixMultiFileTestGenerated extends AbstractQuickFixMultiFileTes
 
     }
 
+    @TestMetadata("idea/testData/quickfix/removeUnused")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RemoveUnused extends AbstractQuickFixMultiFileTest {
+        public void testAllFilesPresentInRemoveUnused() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/removeUnused"), Pattern.compile("^(\\w+)\\.((before\\.Main\\.\\w+)|(test))$"), true);
+        }
+
+        @TestMetadata("usedObjectAsAliasMulti.before.Main.kt")
+        public void testUsedObjectAsAliasMulti() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/usedObjectAsAliasMulti.before.Main.kt");
+            doTestWithExtraFile(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/suppress")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

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

@@ -6856,11 +6856,29 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             doTest(fileName);
         }
 
+        @TestMetadata("usedClassAsAlias.kt")
+        public void testUsedClassAsAlias() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/usedClassAsAlias.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("usedFunAsAlias.kt")
+        public void testUsedFunAsAlias() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/usedFunAsAlias.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("usedObjectAsAlias.kt")
         public void testUsedObjectAsAlias() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/usedObjectAsAlias.kt");
             doTest(fileName);
         }
+
+        @TestMetadata("usedVarAsAlias.kt")
+        public void testUsedVarAsAlias() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/removeUnused/usedVarAsAlias.kt");
+            doTest(fileName);
+        }
     }
 
     @TestMetadata("idea/testData/quickfix/removeUnusedReceiver")