Always allow end=-1

Author: Andy Hanson

src/compiler/transformers/es2015.ts

@@ -1874,7 +1874,7 @@ namespace ts {
                 // for the statement list we synthesize when we down-level an arrow function with
                 // an expression function body. This prevents both comments and source maps from
                 // being emitted for the end position only.
-                statementsLocation = moveRangeEnd(body, -1, /*noAssert*/ true);
+                statementsLocation = moveRangeEnd(body, -1);
 
                 const equalsGreaterThanToken = (<ArrowFunction>node).equalsGreaterThanToken;
                 if (!nodeIsSynthesized(equalsGreaterThanToken) && !nodeIsSynthesized(body)) {
@@ -2328,7 +2328,7 @@ namespace ts {
                                     node.initializer
                                 )
                             ),
-                            moveRangeEnd(node.initializer, -1, /*noAssert*/ true)
+                            moveRangeEnd(node.initializer, -1)
                         )
                     );
                 }
@@ -2343,7 +2343,7 @@ namespace ts {
                 }
                 else {
                     assignment.end = node.initializer.end;
-                    statements.push(setTextRange(createStatement(visitNode(assignment, visitor, isExpression)), moveRangeEnd(node.initializer, -1, /*noAssert*/ true)));
+                    statements.push(setTextRange(createStatement(visitNode(assignment, visitor, isExpression)), moveRangeEnd(node.initializer, -1)));
                 }
             }
 

src/compiler/utilities.ts

@@ -3686,8 +3686,8 @@ namespace ts {
      * @param pos The start position.
      * @param end The end position.
      */
-    export function createRange(pos: number, end: number = pos, noAssert = false): TextRange {
-        Debug.assert(noAssert || end >= pos);
+    export function createRange(pos: number, end: number = pos): TextRange {
+        Debug.assert(end >= pos || end === -1);
         return { pos, end };
     }
 
@@ -3697,8 +3697,8 @@ namespace ts {
      * @param range A TextRange.
      * @param end The new end position.
      */
-    export function moveRangeEnd(range: TextRange, end: number, noAssert = false): TextRange {
-        return createRange(range.pos, end, noAssert);
+    export function moveRangeEnd(range: TextRange, end: number): TextRange {
+        return createRange(range.pos, end);
     }
 
     /**