indent using list start position before first list item

Author: saschanaz

src/services/formatting/smartIndenter.ts

@@ -72,6 +72,12 @@ namespace ts.formatting {
                 }
             }
 
+            const containerList = getListByPosition(position, precedingToken.parent);
+            // use list position if the preceding token is before any list items
+            if (containerList && !rangeContainsRange(containerList, precedingToken)) {
+                return getActualIndentationForListStartLine(containerList, sourceFile, options) + options.indentSize;
+            }
+
             // try to find node that can contribute to indentation and includes 'position' starting from 'precedingToken'
             // if such node is found - compute initial indentation for 'position' inside this node
             let previous: Node;
@@ -342,6 +348,13 @@ namespace ts.formatting {
             }
         }
 
+        function getActualIndentationForListStartLine(list: NodeArray<Node>, sourceFile: SourceFile, options: EditorSettings): number {
+            if (!list) {
+                return Value.Unknown;
+            }
+            return findColumnForFirstNonWhitespaceCharacterInLine(sourceFile.getLineAndCharacterOfPosition(list.pos), sourceFile, options);
+        }
+
         function getActualIndentationForListItem(node: Node, sourceFile: SourceFile, options: EditorSettings): number {
             const containingList = getContainingList(node, sourceFile);
             return containingList ? getActualIndentationFromList(containingList) : Value.Unknown;