Fix detection of bad catch-clauses and try-statements

pkg/analysis_server/lib/src/services/completion/statement/statement_completion.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library services.src.completion.statement;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
@@ skipping 155 matching lines @@
     // If the source was changed between the constructor and running
     // this asynchronous method, it is not safe to use the unit.
     if (analysisContext.getModificationStamp(source) != fileStamp) {
       return NO_COMPLETION;
     }
     node = new NodeLocator(selectionOffset).searchWithin(unit);
     if (node == null) {
       return NO_COMPLETION;
     }
     // TODO(messick): This needs to work for declarations.
-    node = node.getAncestor((n) => n is Statement);
+    AstNode newNode = node.getAncestor((n) => n is Statement);
+    if (newNode is Block) {
+      Block blockNode = newNode;
+      if (blockNode.statements.isNotEmpty) {
+        node = blockNode.statements[blockNode.statements.length - 1];

[scheglov, 2017/04/24 18:52:33]

blockNode.statements.last

+      } else {
+        newNode = node.getAncestor((n) => n is CatchClause);
+        if (newNode != null) {
+          node = newNode.parent;
+        } else {
+          node = node.getAncestor((n) => n is Statement).parent;
+        }
+      }
+    } else {
+      node = newNode;
+    }
     if (_isEmptyStatement(node)) {
       node = node.parent;
     }
     for (engine.AnalysisError error in statementContext.errors) {
       if (error.offset >= node.offset &&
           error.offset <= node.offset + node.length) {
         if (error.errorCode is! HintCode) {
           errors.add(error);
         }
       }
@@ skipping 468 matching lines @@
         // keywordSpace
         sb = new SourceBuilder(file, tryNode.tryKeyword.end + 1);
       } else {
         // keywordOnly
         sb = new SourceBuilder(file, tryNode.tryKeyword.end);
         sb.append(' ');
       }
       _appendEmptyBraces(sb, true);
       _insertBuilder(sb);
       sb = null;
-    } else if ((catchNode = _firstInvalidCatch(tryNode.catchClauses)) != null) {
+    } else if ((catchNode = _findInvalidCatch(tryNode.catchClauses)) != null) {
       if (catchNode.onKeyword != null) {
         if (catchNode.exceptionType.length == 0) {
           String src = utils.getNodeText(catchNode);
           if (src.startsWith(new RegExp(r'on[ \t]+'))) {
             if (src.startsWith(new RegExp(r'on[ \t][ \t]+'))) {
               // onSpaces
               exitPosition = new Position(file, catchNode.onKeyword.end + 1);
               sb = new SourceBuilder(file, catchNode.onKeyword.end + 2);
               addSpace = false;
             } else {
@@ skipping 73 matching lines @@
         errors.firstWhere((err) => err.errorCode == code, orElse: () => null);
     if (error != null) {
       if (partialMatch != null) {
         return error.message.contains(partialMatch) ? error : null;
       }
       return error;
     }
     return null;
   }
 
-  CatchClause _firstInvalidCatch(NodeList<CatchClause> list) {
-    return list.firstWhere((e) {
-      bool found = false;
-      for (var error in errors) {
-        if (error.offset >= e.offset && error.offset <= e.end) {
-          if (error.errorCode is! HintCode) {
-            found = true;
-            break;
-          }
-        }
-      }
-      return found;
-    }, orElse: () => null);
+  CatchClause _findInvalidCatch(NodeList<CatchClause> list) {
+    return list.firstWhere(
+        (catchClause) =>
+            selectionOffset >= catchClause.offset &&
+            selectionOffset <= catchClause.end,
+        orElse: () => null);
   }
 
   LinkedEditGroup _getLinkedPosition(String groupId) {
     LinkedEditGroup group = linkedPositionGroups[groupId];
     if (group == null) {
       group = new LinkedEditGroup.empty();
       linkedPositionGroups[groupId] = group;
     }
     return group;
   }
@@ skipping 74 matching lines @@
   final Token keyword;
   final Token leftParenthesis, rightParenthesis;
   final Expression condition;
   final Statement block;
 
   _KeywordConditionBlockStructure(this.keyword, this.leftParenthesis,
       this.condition, this.rightParenthesis, this.block);
 
   int get offset => keyword.offset;
 }