Added rules for spacing around decorators, computing the undecorated start line of a node

src/compiler/utilities.ts

@@ -150,14 +150,20 @@ module ts {
         return !nodeIsMissing(node);
     }
 
-    export function getTokenPosOfNode(node: Node, sourceFile?: SourceFile): number {
+    export function getTokenPosOfNode(node: Node, sourceFile?: SourceFile, skipDecorators?: boolean): number {
         // With nodes that have no width (i.e. 'Missing' nodes), we actually *don't*
         // want to skip trivia because this will launch us forward to the next token.
         if (nodeIsMissing(node)) {
             return node.pos;
         }
 
-        return skipTrivia((sourceFile || getSourceFileOfNode(node)).text, node.pos);
+        let pos = node.pos;
+        if (skipDecorators && node.decorators) {
+            // Skip past decorators
+            pos = node.decorators.end;
+        }
+
+        return skipTrivia((sourceFile || getSourceFileOfNode(node)).text, pos);
     }
 
     export function getSourceTextOfNodeFromSourceFile(sourceFile: SourceFile, node: Node): string {

src/services/formatting/formatting.ts

@@ -328,8 +328,13 @@ module ts.formatting {
 
         if (formattingScanner.isOnToken()) {
             let startLine = sourceFile.getLineAndCharacterOfPosition(enclosingNode.getStart(sourceFile)).line;
+            let undecoratedStartLine = startLine;
+            if (enclosingNode.decorators) {
+                undecoratedStartLine = sourceFile.getLineAndCharacterOfPosition(enclosingNode.getStart(sourceFile, /*skipDecorators*/ true)).line;
+            }
+
             let delta = getOwnOrInheritedDelta(enclosingNode, options, sourceFile);
-            processNode(enclosingNode, enclosingNode, startLine, initialIndentation, delta);
+            processNode(enclosingNode, enclosingNode, startLine, undecoratedStartLine, initialIndentation, delta);
         }
 
         formattingScanner.close();
@@ -500,7 +505,7 @@ module ts.formatting {
             }
         }
 
-        function processNode(node: Node, contextNode: Node, nodeStartLine: number, indentation: number, delta: number) {
+        function processNode(node: Node, contextNode: Node, nodeStartLine: number, undecoratedNodeStartLine: number, indentation: number, delta: number) {
             if (!rangeOverlapsWithStartEnd(originalRange, node.getStart(sourceFile), node.getEnd())) {
                 return;
             }
@@ -526,7 +531,7 @@ module ts.formatting {
             forEachChild(
                 node,
                 child => {
-                    processChildNode(child, /*inheritedIndentation*/ Constants.Unknown, node, nodeDynamicIndentation, nodeStartLine, /*isListElement*/ false)
+                    processChildNode(child, /*inheritedIndentation*/ Constants.Unknown, node, nodeDynamicIndentation, nodeStartLine, undecoratedNodeStartLine, /*isListElement*/ false)
                 },
                 (nodes: NodeArray<Node>) => {
                     processChildNodes(nodes, node, nodeStartLine, nodeDynamicIndentation);
@@ -547,11 +552,17 @@ module ts.formatting {
                 parent: Node,
                 parentDynamicIndentation: DynamicIndentation,
                 parentStartLine: number,
+                undecoratedParentStartLine: number,
                 isListItem: boolean): number {
 
                 let childStartPos = child.getStart(sourceFile);
 
-                let childStart = sourceFile.getLineAndCharacterOfPosition(childStartPos);
+                let childStartLine = sourceFile.getLineAndCharacterOfPosition(childStartPos).line;
+
+                let undecoratedChildStartLine = childStartLine;
+                if (child.decorators) {
+                    undecoratedChildStartLine = sourceFile.getLineAndCharacterOfPosition(child.getStart(sourceFile, /*skipDecorators*/ true)).line;
+                }
 
                 // if child is a list item - try to get its indentation
                 let childIndentationAmount = Constants.Unknown;
@@ -594,9 +605,10 @@ module ts.formatting {
                     return inheritedIndentation;
                 }
 
-                let childIndentation = computeIndentation(child, childStart.line, childIndentationAmount, node, parentDynamicIndentation, parentStartLine);
+                let effectiveParentStartLine = child.kind === SyntaxKind.Decorator ? childStartLine : undecoratedParentStartLine;
+                let childIndentation = computeIndentation(child, childStartLine, childIndentationAmount, node, parentDynamicIndentation, effectiveParentStartLine);
 
-                processNode(child, childContextNode, childStart.line, childIndentation.indentation, childIndentation.delta);
+                processNode(child, childContextNode, childStartLine, undecoratedChildStartLine, childIndentation.indentation, childIndentation.delta);
 
                 childContextNode = node;
 
@@ -640,7 +652,7 @@ module ts.formatting {
 
                 let inheritedIndentation = Constants.Unknown;
                 for (let child of nodes) {
-                    inheritedIndentation = processChildNode(child, inheritedIndentation, node, listDynamicIndentation, startLine, /*isListElement*/ true)
+                    inheritedIndentation = processChildNode(child, inheritedIndentation, node, listDynamicIndentation, startLine, startLine, /*isListElement*/ true)
                 }
 
                 if (listEndToken !== SyntaxKind.Unknown) {

src/services/formatting/rules.ts

@@ -208,6 +208,10 @@ module ts.formatting {
         public SpaceAfterAnonymousFunctionKeyword: Rule;
         public NoSpaceAfterAnonymousFunctionKeyword: Rule;
 
+        // Insert space after @ in decorator
+        public SpaceBeforeAt: Rule;
+        public NoSpaceAfterAt: Rule;
+
         constructor() {
             ///
             /// Common Rules
@@ -344,6 +348,10 @@ module ts.formatting {
             // Remove spaces in empty interface literals. e.g.: x: {}
             this.NoSpaceBetweenEmptyInterfaceBraceBrackets = new Rule(RuleDescriptor.create1(SyntaxKind.OpenBraceToken, SyntaxKind.CloseBraceToken), RuleOperation.create2(new RuleOperationContext(Rules.IsSameLineTokenContext, Rules.IsObjectTypeContext), RuleAction.Delete));
 
+            // decorators
+            this.SpaceBeforeAt = new Rule(RuleDescriptor.create2(Shared.TokenRange.Any, SyntaxKind.AtToken), RuleOperation.create2(new RuleOperationContext(Rules.IsSameLineTokenContext), RuleAction.Space));
+            this.NoSpaceAfterAt = new Rule(RuleDescriptor.create3(SyntaxKind.AtToken, Shared.TokenRange.Any), RuleOperation.create2(new RuleOperationContext(Rules.IsSameLineTokenContext), RuleAction.Delete));
+
             // These rules are higher in priority than user-configurable rules.
             this.HighPriorityCommonRules =
             [
@@ -381,7 +389,9 @@ module ts.formatting {
                 this.NoSpaceBetweenCloseParenAndAngularBracket,
                 this.NoSpaceAfterOpenAngularBracket,
                 this.NoSpaceBeforeCloseAngularBracket,
-                this.NoSpaceAfterCloseAngularBracket
+                this.NoSpaceAfterCloseAngularBracket,
+                this.SpaceBeforeAt,
+                this.NoSpaceAfterAt,
             ];
 
             // These rules are lower in priority than user-configurable rules.

src/services/services.ts

@@ -19,7 +19,7 @@ module ts {
         getChildCount(sourceFile?: SourceFile): number;
         getChildAt(index: number, sourceFile?: SourceFile): Node;
         getChildren(sourceFile?: SourceFile): Node[];
-        getStart(sourceFile?: SourceFile): number;
+        getStart(sourceFile?: SourceFile, skipDecorators?: boolean): number;
         getFullStart(): number;
         getEnd(): number;
         getWidth(sourceFile?: SourceFile): number;
@@ -149,8 +149,8 @@ module ts {
             return getSourceFileOfNode(this);
         }
 
-        public getStart(sourceFile?: SourceFile): number {
-            return getTokenPosOfNode(this, sourceFile);
+        public getStart(sourceFile?: SourceFile, skipDecorators?: boolean): number {
+            return getTokenPosOfNode(this, sourceFile, skipDecorators);
         }
 
         public getFullStart(): number {