Fix false positive "Unused import directive" for imports under several alias

#KT-30949 Fixed

compiler/psi/src/org/jetbrains/kotlin/psi/KtFile.kt

@@ -175,7 +175,7 @@ open class KtFile(viewProvider: FileViewProvider, val isCompiled: Boolean) :
         importDirectives.firstOrNull { name == it.aliasName }
 
     fun findAliasByFqName(fqName: FqName): KtImportAlias? = importDirectives.firstOrNull {
-        fqName == it.importedFqName
+        it.alias != null && fqName == it.importedFqName
     }?.alias
 
     @Deprecated("") // getPackageFqName should be used instead

idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt

@@ -42,7 +42,6 @@ import org.jetbrains.kotlin.resolve.ImportPath
 import org.jetbrains.kotlin.resolve.descriptorUtil.getImportableDescriptor
 import org.jetbrains.kotlin.resolve.scopes.HierarchicalScope
 import org.jetbrains.kotlin.resolve.scopes.utils.*
-import java.util.*
 
 class KotlinImportOptimizer : ImportOptimizer {
     override fun supports(file: PsiFile?) = file is KtFile
@@ -74,6 +73,12 @@ class KotlinImportOptimizer : ImportOptimizer {
 
     private class CollectUsedDescriptorsVisitor(file: KtFile) : KtVisitorVoid() {
         private val currentPackageName = file.packageFqName
+        private val withAlias: Set<FqName> = file.importDirectives
+            .asSequence()
+            .filter { it.alias != null && it.aliasName != it.importPath?.fqName?.shortName()?.asString() }
+            .mapNotNull(KtImportDirective::importedFqName)
+            .toSet()
+
         private val descriptorsToImport = HashSet<DeclarationDescriptor>()
         private val abstractRefs = ArrayList<OptimizedImportsBuilder.AbstractReference>()
 
@@ -107,7 +112,7 @@ class KotlinImportOptimizer : ImportOptimizer {
                     val importableFqName = target.importableFqName ?: continue
                     val parentFqName = importableFqName.parent()
                     if (target is PackageViewDescriptor && parentFqName == FqName.ROOT) continue // no need to import top-level packages
-                    if (target !is PackageViewDescriptor && parentFqName == currentPackageName) continue
+                    if (target !is PackageViewDescriptor && parentFqName == currentPackageName && importableFqName !in withAlias) continue
 
                     if (!reference.canBeResolvedViaImport(target, bindingContext)) continue
 

idea/testData/editor/optimizeImports/common/ConflictWithAlias.dependency.kt

@@ -0,0 +1 @@
+const val name = 42

idea/testData/editor/optimizeImports/common/ConflictWithAlias.kt

@@ -0,0 +1,4 @@
+import name
+import name as names
+
+val a = name

idea/testData/editor/optimizeImports/common/ConflictWithAlias.kt.after

@@ -0,0 +1,4 @@
+import name
+import name as names
+
+val a = name

idea/testData/editor/optimizeImports/common/ConflictWithAlias2.dependency.kt

@@ -0,0 +1,5 @@
+package duration
+
+val Int.hours: Int get() = TODO()
+val Int.minutes: Int get() = TODO()
+val Int.seconds: Int get() = TODO()

idea/testData/editor/optimizeImports/common/ConflictWithAlias2.kt

@@ -0,0 +1,11 @@
+import duration.*
+import duration.hours as hour
+import duration.minutes as minute
+import duration.minutes as minutes
+import duration.seconds as second
+import duration.seconds as seconds
+
+fun main() {
+    val totalDuration = 1.hour - 30.minutes + 1.second
+    println(totalDuration)
+}

idea/testData/editor/optimizeImports/common/ConflictWithAlias2.kt.after

@@ -0,0 +1,8 @@
+import duration.minutes
+import duration.hours as hour
+import duration.seconds as second
+
+fun main() {
+    val totalDuration = 1.hour - 30.minutes + 1.second
+    println(totalDuration)
+}

idea/testData/editor/optimizeImports/common/ConflictWithAlias2.kt.log

@@ -0,0 +1,13 @@
+Additional checking of reference Getter: hour
+Additional checking of reference KtSimpleNameReference: hour
+Changed resolve of KtSimpleNameReference: hour
+Additional checking of reference Getter: second
+Additional checking of reference KtSimpleNameReference: second
+Changed resolve of KtSimpleNameReference: second
+Trying to build import list again with import rules: +duration.hours as hour, +duration.seconds as second
+Additional checking of reference Getter: hour
+Additional checking of reference KtSimpleNameReference: hour
+Changed resolve of KtSimpleNameReference: hour
+Additional checking of reference Getter: second
+Additional checking of reference KtSimpleNameReference: second
+Changed resolve of KtSimpleNameReference: second

idea/testData/inspections/unusedImport/noUnusedImportForImportsWithSameName.Dependency.kt

@@ -0,0 +1 @@
+const val name = 42

idea/testData/inspections/unusedImport/noUnusedImportForImportsWithSameName.kt

@@ -0,0 +1,4 @@
+import name
+import name as names
+
+val a = name

idea/tests/org/jetbrains/kotlin/idea/imports/JsOptimizeImportsTestGenerated.java

@@ -64,6 +64,16 @@ public class JsOptimizeImportsTestGenerated extends AbstractJsOptimizeImportsTes
             runTest("idea/testData/editor/optimizeImports/common/ComponentFunction.kt");
         }
 
+        @TestMetadata("ConflictWithAlias.kt")
+        public void testConflictWithAlias() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ConflictWithAlias.kt");
+        }
+
+        @TestMetadata("ConflictWithAlias2.kt")
+        public void testConflictWithAlias2() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ConflictWithAlias2.kt");
+        }
+
         @TestMetadata("CurrentPackage.kt")
         public void testCurrentPackage() throws Exception {
             runTest("idea/testData/editor/optimizeImports/common/CurrentPackage.kt");

idea/tests/org/jetbrains/kotlin/idea/imports/JvmOptimizeImportsTestGenerated.java

@@ -257,6 +257,16 @@ public class JvmOptimizeImportsTestGenerated extends AbstractJvmOptimizeImportsT
             runTest("idea/testData/editor/optimizeImports/common/ComponentFunction.kt");
         }
 
+        @TestMetadata("ConflictWithAlias.kt")
+        public void testConflictWithAlias() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ConflictWithAlias.kt");
+        }
+
+        @TestMetadata("ConflictWithAlias2.kt")
+        public void testConflictWithAlias2() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ConflictWithAlias2.kt");
+        }
+
         @TestMetadata("CurrentPackage.kt")
         public void testCurrentPackage() throws Exception {
             runTest("idea/testData/editor/optimizeImports/common/CurrentPackage.kt");