Emit leading comments for '}' of the function block

Fixes #503

Author: sheetalkamat

src/compiler/emitter.ts

@@ -330,6 +330,8 @@ module ts {
             /** Emit Trailing comments of the node */
             var emitTrailingComments = compilerOptions.removeComments ? (node: Node) => { } : emitTrailingDeclarationComments;
 
+            var emitLeadingCommentsOfPosition = compilerOptions.removeComments ? (pos: number) => { } : emitLeadingCommentsOfLocalPosition;
+
             var detachedCommentsInfo: { nodePos: number; detachedCommentEndPos: number }[];
             /** Emit detached comments of the node */
             var emitDetachedComments = compilerOptions.removeComments ? (node: TextRange) => { } : emitDetachedCommentsAtPosition;
@@ -1390,12 +1392,14 @@ module ts {
                         write(";");
                         emitTrailingComments(node.body);
                     }
-                    decreaseIndent();
                     writeLine();
                     if (node.body.kind === SyntaxKind.FunctionBlock) {
+                        emitLeadingCommentsOfPosition((<Block>node.body).statements.end);
+                        decreaseIndent();
                         emitToken(SyntaxKind.CloseBraceToken, (<Block>node.body).statements.end);
                     }
                     else {
+                        decreaseIndent();
                         emitStart(node.body);
                         write("}");
                         emitEnd(node.body);
@@ -2077,23 +2081,34 @@ module ts {
                 }
             }
 
+            function hasDetachedComments(pos: number) {
+                return detachedCommentsInfo !== undefined && detachedCommentsInfo[detachedCommentsInfo.length - 1].nodePos === pos;
+            }
+
+            function getLeadingCommentsWithoutDetachedComments() {
+                // get the leading comments from detachedPos
+                var leadingComments = getLeadingComments(currentSourceFile.text, detachedCommentsInfo[detachedCommentsInfo.length - 1].detachedCommentEndPos);
+                if (detachedCommentsInfo.length - 1) {
+                    detachedCommentsInfo.pop();
+                }
+                else {
+                    detachedCommentsInfo = undefined;
+                }
+
+                return leadingComments;
+            }
+
             function emitLeadingDeclarationComments(node: Node) {
                 // Emit the leading comments only if the parent's pos doesnt match because parent should take care of emitting these comments
                 if (node.parent.kind === SyntaxKind.SourceFile || node.pos !== node.parent.pos) {
                     var leadingComments: Comment[];
-                    if (detachedCommentsInfo === undefined || detachedCommentsInfo[detachedCommentsInfo.length - 1].nodePos !== node.pos) {
-                        // get the leading comments from the node
-                        leadingComments = getLeadingCommentsOfNode(node, currentSourceFile);
+                    if (hasDetachedComments(node.pos)) {
+                        // get comments without detached comments
+                        leadingComments = getLeadingCommentsWithoutDetachedComments();
                     }
                     else {
-                        // get the leading comments from detachedPos
-                        leadingComments = getLeadingComments(currentSourceFile.text, detachedCommentsInfo[detachedCommentsInfo.length - 1].detachedCommentEndPos);
-                        if (detachedCommentsInfo.length - 1) {
-                            detachedCommentsInfo.pop();
-                        }
-                        else {
-                            detachedCommentsInfo = undefined;
-                        }
+                        // get the leading comments from the node
+                        leadingComments = getLeadingCommentsOfNode(node, currentSourceFile);
                     }
                     emitNewLineBeforeLeadingComments(node, leadingComments, writer);
                     // Leading comments are emitted at /*leading comment1 */space/*leading comment*/space
@@ -2110,6 +2125,21 @@ module ts {
                 }
             }
 
+            function emitLeadingCommentsOfLocalPosition(pos: number) {
+                var leadingComments: Comment[];
+                if (hasDetachedComments(pos)) {
+                    // get comments without detached comments
+                    leadingComments = getLeadingCommentsWithoutDetachedComments();
+                }
+                else {
+                    // get the leading comments from the node
+                    leadingComments = getLeadingComments(currentSourceFile.text, pos);
+                }
+                emitNewLineBeforeLeadingComments({ pos: pos, end: pos }, leadingComments, writer);
+                // Leading comments are emitted at /*leading comment1 */space/*leading comment*/space
+                emitComments(leadingComments, /*trailingSeparator*/ true, writer, writeComment);
+            }
+
             function emitDetachedCommentsAtPosition(node: TextRange) {
                 var leadingComments = getLeadingComments(currentSourceFile.text, node.pos);
                 if (leadingComments) {

tests/baselines/reference/classMemberInitializerWithLamdaScoping.js

@@ -52,6 +52,8 @@ var Test1 = (function () {
         this.field1 = field1;
         this.messageHandler = function () {
             console.log(field1); // But this should be error as the field1 will resolve to var field1 
+            // but since this code would be generated inside constructor, in generated js
+            // it would resolve to private field1 and thats not what user intended here. 
         };
     }
     Test1.staticMessageHandler = function () {

tests/baselines/reference/classMemberInitializerWithLamdaScoping2.js

@@ -25,6 +25,8 @@ var Test1 = (function () {
         this.field1 = field1;
         this.messageHandler = function () {
             console.log(field1); // But this should be error as the field1 will resolve to var field1 
+            // but since this code would be generated inside constructor, in generated js
+            // it would resolve to private field1 and thats not what user intended here. 
         };
     }
     return Test1;

tests/baselines/reference/classOrder1.js

@@ -16,6 +16,7 @@ var A = (function () {
     function A() {
     }
     A.prototype.foo = function () {
+        /*WScript.Echo("Here!");*/
     };
     return A;
 })();

tests/baselines/reference/commentsFunction.js

@@ -41,7 +41,19 @@ lambdaFoo = (a, b) => a * b; // This is trailing comment
 /*leading comment*/(() => 0); //trailing comment
 
 function blah4(/*1*/a: string/*2*/,/*3*/b: string/*4*/) {
-}
+}
+
+function foo1() {
+
+    // should emit this
+}
+
+function foo2() {
+    /// This is some detached comment
+
+    // should emit this leading comment of } too
+}
+
 
 //// [commentsFunction.js]
 /** This comment should appear for foo*/
@@ -79,6 +91,13 @@ lambdaFoo = function (a, b) { return a * b; }; // This is trailing comment
 /*leading comment*/ (function () { return 0; }); //trailing comment
 function blah4(/*1*/ a /*2*/, /*3*/ b /*4*/) {
 }
+function foo1() {
+    // should emit this
+}
+function foo2() {
+    /// This is some detached comment
+    // should emit this leading comment of } too
+}
 
 
 //// [commentsFunction.d.ts]
@@ -98,3 +117,5 @@ declare function blah(a: string): void;
 declare function blah2(a: string): void;
 declare function blah3(a: string): void;
 declare function blah4(a: string, b: string): void;
+declare function foo1(): void;
+declare function foo2(): void;

tests/baselines/reference/commentsFunction.types

@@ -110,3 +110,18 @@ function blah4(/*1*/a: string/*2*/,/*3*/b: string/*4*/) {
 >a : string
 >b : string
 }
+
+function foo1() {
+>foo1 : () => void
+
+    // should emit this
+}
+
+function foo2() {
+>foo2 : () => void
+
+    /// This is some detached comment
+
+    // should emit this leading comment of } too
+}
+

tests/baselines/reference/genericCallWithGenericSignatureArguments.js

@@ -66,6 +66,8 @@ function other2(x) {
     var r7 = foo(function (a) { return a; }, function (b) { return b; }); // T => T
     var r7b = foo(function (a) { return a; }, function (b) { return b; }); // {} => {}
     var r8 = r7(null);
+    // BUG 835518
+    //var r9 = r7(new Date());
 }
 function foo2(a, b) {
     var r;

tests/baselines/reference/genericCallWithObjectTypeArgsAndNumericIndexer.js

@@ -54,4 +54,6 @@ function other3(arg) {
     var b;
     var r2 = foo(b);
     var d = r2[1];
+    // BUG 821629
+    //var u: U = r2[1]; // ok
 }

tests/baselines/reference/genericCallWithObjectTypeArgsAndStringIndexer.js

@@ -55,4 +55,6 @@ function other3(arg) {
     var b;
     var r2 = foo(b);
     var d = r2['hm']; // ok
+    // BUG 821629
+    //var u: U = r2['hm']; // ok
 }

tests/baselines/reference/logicalOrOperatorWithTypeParameters.js

@@ -37,6 +37,7 @@ function fn2(t, u, v) {
     var r4 = u || u;
     var r5 = u || v;
     var r6 = u || v;
+    //var r7: T = u || v;
 }
 function fn3(t, u) {
     var r1 = t || u;