Don't remove unused imports when there are unresolved symbols.

R=brianwilkerson@google.com, devoncarew@google.com

Bug: dart-lang/sdk#32124
Change-Id: If1b7b57bd98922768f28584325f668ba612c69d7
Reviewed-on: https://dart-review.googlesource.com/48705
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

Author: scheglov

pkg/analysis_server/lib/src/services/correction/organize_directives.dart

@@ -19,13 +19,18 @@ class DirectiveOrganizer {
   final List<AnalysisError> errors;
   final bool removeUnresolved;
   final bool removeUnused;
+
   String code;
   String endOfLine;
+  bool hasUnresolvedIdentifierError;
 
   DirectiveOrganizer(this.initialCode, this.unit, this.errors,
       {this.removeUnresolved: true, this.removeUnused: true}) {
     this.code = initialCode;
     this.endOfLine = getEOL(code);
+    this.hasUnresolvedIdentifierError = errors.any((error) {
+      return error.errorCode.isUnresolvedIdentifier;
+    });
   }
 
   /**
@@ -68,7 +73,7 @@ class DirectiveOrganizer {
   }
 
   /**
-   * Oraganize all [Directive]s.
+   * Organize all [Directive]s.
    */
   void _organizeDirectives() {
     List<_DirectiveInfo> directives = [];
@@ -99,11 +104,14 @@ class DirectiveOrganizer {
       StringBuffer sb = new StringBuffer();
       _DirectivePriority currentPriority = null;
       for (_DirectiveInfo directiveInfo in directives) {
-        if (removeUnresolved && _isUnresolvedUri(directiveInfo.directive)) {
-          continue;
-        }
-        if (removeUnused && _isUnusedImport(directiveInfo.directive)) {
-          continue;
+        if (!hasUnresolvedIdentifierError) {
+          UriBasedDirective directive = directiveInfo.directive;
+          if (removeUnresolved && _isUnresolvedUri(directive)) {
+            continue;
+          }
+          if (removeUnused && _isUnusedImport(directive)) {
+            continue;
+          }
         }
         if (currentPriority != directiveInfo.priority) {
           if (sb.length != 0) {

pkg/analysis_server/test/services/correction/organize_directives_test.dart

@@ -185,6 +185,27 @@ main() {
 }''', removeUnresolved: true, removeUnused: true);
   }
 
+  test_remove_unusedImports_hasUnresolvedError() async {
+    Future<void> check(String declaration) async {
+      String code = '''
+import 'dart:async';
+$declaration
+''';
+      await _computeUnitAndErrors(code);
+      _assertOrganize(code, removeUnused: true);
+    }
+
+    await check('main() { Unresolved v; }');
+    await check('main() { new Unresolved(); }');
+    await check('main() { const Unresolved(); }');
+    await check('main() { unresolvedFunction(); }');
+    await check('main() { print(unresolvedVariable); }');
+    await check('main() { unresolvedVariable = 0; }');
+    await check('main() { Unresolved.field = 0; }');
+    await check('class A extends Unresolved {}');
+    await check('List<Unresolved> v;');
+  }
+
   test_sort() async {
     await _computeUnitAndErrors(r'''
 library lib;