CR feedback + Consistent error spans on case/default clauses

Author: ahejlsberg

src/compiler/checker.ts

@@ -31054,10 +31054,7 @@ namespace ts {
                         firstDefaultClause = clause;
                     }
                     else {
-                        const sourceFile = getSourceFileOfNode(node);
-                        const start = skipTrivia(sourceFile.text, clause.pos);
-                        const end = clause.statements.length > 0 ? clause.statements[0].pos : clause.end;
-                        grammarErrorAtPos(sourceFile, start, end - start, Diagnostics.A_default_clause_cannot_appear_more_than_once_in_a_switch_statement);
+                        grammarErrorOnNode(clause, Diagnostics.A_default_clause_cannot_appear_more_than_once_in_a_switch_statement);
                         hasDuplicateDefaultClause = true;
                     }
                 }
@@ -31080,7 +31077,7 @@ namespace ts {
                 }
                 forEach(clause.statements, checkSourceElement);
                 if (compilerOptions.noFallthroughCasesInSwitch && clause.fallthroughFlowNode && isReachableFlowNode(clause.fallthroughFlowNode)) {
-                    grammarErrorOnFirstToken(clause, Diagnostics.Fallthrough_case_in_switch);
+                    error(clause, Diagnostics.Fallthrough_case_in_switch);
                 }
             });
             if (node.caseBlock.locals) {

src/compiler/utilities.ts

@@ -961,6 +961,11 @@ namespace ts {
                 break;
             case SyntaxKind.ArrowFunction:
                 return getErrorSpanForArrowFunction(sourceFile, <ArrowFunction>node);
+            case SyntaxKind.CaseClause:
+            case SyntaxKind.DefaultClause:
+                const start = skipTrivia(sourceFile.text, (<CaseOrDefaultClause>node).pos);
+                const end = (<CaseOrDefaultClause>node).statements.length > 0 ? (<CaseOrDefaultClause>node).statements[0].pos : (<CaseOrDefaultClause>node).end;
+                return createTextSpanFromBounds(start, end);
         }
 
         if (errorNode === undefined) {