indent inside mapped type

Author: saschanaz

src/services/formatting/formatting.ts

@@ -488,14 +488,16 @@ namespace ts.formatting {
                         // open and close brace, 'else' and 'while' (in do statement) tokens has indentation of the parent
                         case SyntaxKind.OpenBraceToken:
                         case SyntaxKind.CloseBraceToken:
-                        case SyntaxKind.OpenBracketToken:
-                        case SyntaxKind.CloseBracketToken:
                         case SyntaxKind.OpenParenToken:
                         case SyntaxKind.CloseParenToken:
                         case SyntaxKind.ElseKeyword:
                         case SyntaxKind.WhileKeyword:
                         case SyntaxKind.AtToken:
                             return indentation;
+                        case SyntaxKind.OpenBracketToken:
+                        case SyntaxKind.CloseBracketToken:
+                            return (container.kind === SyntaxKind.MappedType) ?
+                                indentation + getEffectiveDelta(delta, container) : indentation;
                         default:
                             // if token line equals to the line of containing node (this is a first token in the node) - use node indentation
                             return nodeStartLine !== line ? indentation + getEffectiveDelta(delta, container) : indentation;

src/services/formatting/smartIndenter.ts

@@ -438,6 +438,7 @@ namespace ts.formatting {
                 case SyntaxKind.ModuleBlock:
                 case SyntaxKind.ObjectLiteralExpression:
                 case SyntaxKind.TypeLiteral:
+                case SyntaxKind.MappedType:
                 case SyntaxKind.TupleType:
                 case SyntaxKind.CaseBlock:
                 case SyntaxKind.DefaultClause:

tests/cases/fourslash/formattingMappedType.ts

@@ -0,0 +1,12 @@
+/// <reference path='fourslash.ts' />
+
+/////*generic*/type t  < T  > =   {
+/////*map*/   [   P   in   keyof    T  ]   :   T  [  P  ]
+////};
+
+
+format.document();
+goTo.marker("generic");
+verify.currentLineContentIs("type t<T> = {");
+goTo.marker("map");
+verify.currentLineContentIs("    [P in keyof T]: T[P]");