Upate error message

Author: mhegazy

src/compiler/checker.ts

@@ -2073,7 +2073,7 @@ module ts {
                 }
                 // Handle export default expressions
                 if (declaration.kind === SyntaxKind.ExportAssignment) {
-                    var exportAssignment = (<ExportAssignment>declaration);
+                    var exportAssignment = <ExportAssignment>declaration;
                     if (exportAssignment.expression) {
                         return links.type = checkExpression(exportAssignment.expression);
                     }
@@ -10095,7 +10095,7 @@ module ts {
             if (node.type) {
                 checkSourceElement(node.type);
                 if (!isInAmbientContext(node)) {
-                    grammarErrorOnFirstToken(node.type, Diagnostics.Type_annotation_on_export_statements_are_only_allowed_in_ambient_module_declarations);
+                    grammarErrorOnFirstToken(node.type, Diagnostics.A_type_annotation_on_an_export_statement_is_only_allowed_in_an_ambient_external_module_declaration);
                 }
             }
 

src/compiler/diagnosticInformationMap.generated.ts

@@ -157,7 +157,7 @@ module ts {
         Catch_clause_variable_cannot_have_an_initializer: { code: 1197, category: DiagnosticCategory.Error, key: "Catch clause variable cannot have an initializer." },
         An_extended_Unicode_escape_value_must_be_between_0x0_and_0x10FFFF_inclusive: { code: 1198, category: DiagnosticCategory.Error, key: "An extended Unicode escape value must be between 0x0 and 0x10FFFF inclusive." },
         Unterminated_Unicode_escape_sequence: { code: 1199, category: DiagnosticCategory.Error, key: "Unterminated Unicode escape sequence." },
-        Type_annotation_on_export_statements_are_only_allowed_in_ambient_module_declarations: { code: 1200, category: DiagnosticCategory.Error, key: "Type annotation on export statements are only allowed in ambient module declarations." },
+        A_type_annotation_on_an_export_statement_is_only_allowed_in_an_ambient_external_module_declaration: { code: 1200, category: DiagnosticCategory.Error, key: "A type annotation on an export statement is only allowed in an ambient external module declaration." },
         Duplicate_identifier_0: { code: 2300, category: DiagnosticCategory.Error, key: "Duplicate identifier '{0}'." },
         Initializer_of_instance_member_variable_0_cannot_reference_identifier_1_declared_in_the_constructor: { code: 2301, category: DiagnosticCategory.Error, key: "Initializer of instance member variable '{0}' cannot reference identifier '{1}' declared in the constructor." },
         Static_members_cannot_reference_class_type_parameters: { code: 2302, category: DiagnosticCategory.Error, key: "Static members cannot reference class type parameters." },

src/compiler/diagnosticMessages.json

@@ -619,7 +619,7 @@
         "category": "Error",
         "code": 1199
     },
-    "Type annotation on export statements are only allowed in ambient module declarations.": {
+    "A type annotation on an export statement is only allowed in an ambient external module declaration.": {
         "category": "Error",
         "code": 1200
     },

tests/baselines/reference/exportDefaultTypeAnnoation.errors.txt

@@ -1,8 +1,8 @@
-tests/cases/compiler/exportDefaultTypeAnnoation.ts(2,18): error TS1200: Type annotation on export statements are only allowed in ambient module declarations.
+tests/cases/compiler/exportDefaultTypeAnnoation.ts(2,18): error TS1200: A type annotation on an export statement is only allowed in an ambient external module declaration.
 
 
 ==== tests/cases/compiler/exportDefaultTypeAnnoation.ts (1 errors) ====
 
     export default : number;
                      ~~~~~~
-!!! error TS1200: Type annotation on export statements are only allowed in ambient module declarations.
+!!! error TS1200: A type annotation on an export statement is only allowed in an ambient external module declaration.