Optimize Imports shouldn't delete imports with unresolved parts

#KT-10512 Fixed

idea/ide-common/src/org/jetbrains/kotlin/idea/util/ImportsUtils.kt

@@ -19,10 +19,11 @@
 package org.jetbrains.kotlin.idea.imports
 
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.idea.resolve.ResolutionFacade
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtImportDirective
-import org.jetbrains.kotlin.psi.KtNameReferenceExpression
 import org.jetbrains.kotlin.psi.KtReferenceExpression
+import org.jetbrains.kotlin.psi.KtSimpleNameExpression
 import org.jetbrains.kotlin.psi.psiUtil.getQualifiedElementSelector
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorUtils
@@ -30,6 +31,7 @@ import org.jetbrains.kotlin.resolve.ImportPath
 import org.jetbrains.kotlin.resolve.bindingContextUtil.getReferenceTargets
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.getImportableDescriptor
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.KotlinType
 
 object ImportPathComparator : Comparator<ImportPath> {
@@ -94,5 +96,8 @@ fun KtReferenceExpression.getImportableTargets(bindingContext: BindingContext):
     return targets.map { it.getImportableDescriptor() }.toSet()
 }
 
-fun KtImportDirective.canResolve(): Boolean = (importedReference?.getQualifiedElementSelector() as? KtNameReferenceExpression)
-    ?.reference?.resolve() != null ?: false
+fun KtImportDirective.canResolve(facade: ResolutionFacade): Boolean {
+    return (importedReference?.getQualifiedElementSelector() as? KtSimpleNameExpression)?.let { nameExpression ->
+        nameExpression.getImportableTargets(facade.analyze(nameExpression, BodyResolveMode.PARTIAL)).isNotEmpty()
+    } ?: false
+}

idea/ide-common/src/org/jetbrains/kotlin/idea/util/OptimizedImportsBuilder.kt

@@ -87,8 +87,9 @@ class OptimizedImportsBuilder(
     private val importRules = HashSet<ImportRule>()
 
     fun buildOptimizedImports(): List<ImportPath>? {
+        val facade = file.getResolutionFacade()
         file.importDirectives
-            .filterNot(KtImportDirective::canResolve)
+            .filterNot { it.canResolve(facade) }
             .mapNotNull(KtImportDirective::getImportPath)
             .mapTo(importRules) { ImportRule.Add(it) }
 

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

@@ -0,0 +1,3 @@
+package pack1
+
+class Example

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

@@ -0,0 +1,8 @@
+import pack1.Class4
+import pack1.Example
+import pack2.*
+import pack3.Ggd
+
+fun method(a: Class4) {
+    Example()
+}

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

@@ -0,0 +1,8 @@
+import pack1.Class4
+import pack1.Example
+import pack2.*
+import pack3.Ggd
+
+fun method(a: Class4) {
+    Example()
+}

idea/testData/editor/optimizeImports/jvm/UnusedImports.kt.after

@@ -1,6 +1,7 @@
 import java.util.ArrayList
 import java.util.HashMap
 import kotlin.system.measureTimeMillis
+import kotlin.test.Asserter
 
 class Action {
     fun test() {

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

@@ -174,6 +174,11 @@ public class JsOptimizeImportsTestGenerated extends AbstractJsOptimizeImportsTes
             runTest("idea/testData/editor/optimizeImports/common/TwoConstructors.kt");
         }
 
+        @TestMetadata("UnresolvedImport.kt")
+        public void testUnresolvedImport() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/UnresolvedImport.kt");
+        }
+
         @TestMetadata("idea/testData/editor/optimizeImports/common/kt21515")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

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

@@ -367,6 +367,11 @@ public class JvmOptimizeImportsTestGenerated extends AbstractJvmOptimizeImportsT
             runTest("idea/testData/editor/optimizeImports/common/TwoConstructors.kt");
         }
 
+        @TestMetadata("UnresolvedImport.kt")
+        public void testUnresolvedImport() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/UnresolvedImport.kt");
+        }
+
         @TestMetadata("idea/testData/editor/optimizeImports/common/kt21515")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)