Merge pull request #3078 from Microsoft/asyncFunctions

Async Functions for ES6

Author: rbuckton

Diff for: src/compiler/checker.ts

@@ -203,6 +203,11 @@ namespace ts {
             type: "boolean",
             description: Diagnostics.Watch_input_files,
         },
+        {
+            name: "experimentalAsyncFunctions",
+            type: "boolean",
+            description: Diagnostics.Enables_experimental_support_for_ES7_async_functions
+        },
         {
             name: "experimentalDecorators",
             type: "boolean",

Diff for: src/compiler/commandLineParser.ts

@@ -29,7 +29,12 @@ namespace ts {
         Statements_are_not_allowed_in_ambient_contexts: { code: 1036, category: DiagnosticCategory.Error, key: "Statements are not allowed in ambient contexts." },
         A_declare_modifier_cannot_be_used_in_an_already_ambient_context: { code: 1038, category: DiagnosticCategory.Error, key: "A 'declare' modifier cannot be used in an already ambient context." },
         Initializers_are_not_allowed_in_ambient_contexts: { code: 1039, category: DiagnosticCategory.Error, key: "Initializers are not allowed in ambient contexts." },
+        _0_modifier_cannot_be_used_in_an_ambient_context: { code: 1040, category: DiagnosticCategory.Error, key: "'{0}' modifier cannot be used in an ambient context." },
+        _0_modifier_cannot_be_used_with_a_class_declaration: { code: 1041, category: DiagnosticCategory.Error, key: "'{0}' modifier cannot be used with a class declaration." },
+        _0_modifier_cannot_be_used_here: { code: 1042, category: DiagnosticCategory.Error, key: "'{0}' modifier cannot be used here." },
+        _0_modifier_cannot_appear_on_a_data_property: { code: 1043, category: DiagnosticCategory.Error, key: "'{0}' modifier cannot appear on a data property." },
         _0_modifier_cannot_appear_on_a_module_element: { code: 1044, category: DiagnosticCategory.Error, key: "'{0}' modifier cannot appear on a module element." },
+        A_0_modifier_cannot_be_used_with_an_interface_declaration: { code: 1045, category: DiagnosticCategory.Error, key: "A '{0}' modifier cannot be used with an interface declaration." },
         A_declare_modifier_is_required_for_a_top_level_declaration_in_a_d_ts_file: { code: 1046, category: DiagnosticCategory.Error, key: "A 'declare' modifier is required for a top level declaration in a .d.ts file." },
         A_rest_parameter_cannot_be_optional: { code: 1047, category: DiagnosticCategory.Error, key: "A rest parameter cannot be optional." },
         A_rest_parameter_cannot_have_an_initializer: { code: 1048, category: DiagnosticCategory.Error, key: "A rest parameter cannot have an initializer." },
@@ -38,12 +43,18 @@ namespace ts {
         A_set_accessor_parameter_cannot_have_an_initializer: { code: 1052, category: DiagnosticCategory.Error, key: "A 'set' accessor parameter cannot have an initializer." },
         A_set_accessor_cannot_have_rest_parameter: { code: 1053, category: DiagnosticCategory.Error, key: "A 'set' accessor cannot have rest parameter." },
         A_get_accessor_cannot_have_parameters: { code: 1054, category: DiagnosticCategory.Error, key: "A 'get' accessor cannot have parameters." },
+        Type_0_is_not_a_valid_async_function_return_type: { code: 1055, category: DiagnosticCategory.Error, key: "Type '{0}' is not a valid async function return type." },
         Accessors_are_only_available_when_targeting_ECMAScript_5_and_higher: { code: 1056, category: DiagnosticCategory.Error, key: "Accessors are only available when targeting ECMAScript 5 and higher." },
+        An_async_function_or_method_must_have_a_valid_awaitable_return_type: { code: 1057, category: DiagnosticCategory.Error, key: "An async function or method must have a valid awaitable return type." },
+        Operand_for_await_does_not_have_a_valid_callable_then_member: { code: 1058, category: DiagnosticCategory.Error, key: "Operand for 'await' does not have a valid callable 'then' member." },
+        Return_expression_in_async_function_does_not_have_a_valid_callable_then_member: { code: 1059, category: DiagnosticCategory.Error, key: "Return expression in async function does not have a valid callable 'then' member." },
+        Expression_body_for_async_arrow_function_does_not_have_a_valid_callable_then_member: { code: 1060, category: DiagnosticCategory.Error, key: "Expression body for async arrow function does not have a valid callable 'then' member." },
         Enum_member_must_have_initializer: { code: 1061, category: DiagnosticCategory.Error, key: "Enum member must have initializer." },
+        _0_is_referenced_directly_or_indirectly_in_the_fulfillment_callback_of_its_own_then_method: { code: 1062, category: DiagnosticCategory.Error, key: "{0} is referenced directly or indirectly in the fulfillment callback of its own 'then' method." },
         An_export_assignment_cannot_be_used_in_a_namespace: { code: 1063, category: DiagnosticCategory.Error, key: "An export assignment cannot be used in a namespace." },
         Ambient_enum_elements_can_only_have_integer_literal_initializers: { code: 1066, category: DiagnosticCategory.Error, key: "Ambient enum elements can only have integer literal initializers." },
         Unexpected_token_A_constructor_method_accessor_or_property_was_expected: { code: 1068, category: DiagnosticCategory.Error, key: "Unexpected token. A constructor, method, accessor, or property was expected." },
-        A_declare_modifier_cannot_be_used_with_an_import_declaration: { code: 1079, category: DiagnosticCategory.Error, key: "A 'declare' modifier cannot be used with an import declaration." },
+        A_0_modifier_cannot_be_used_with_an_import_declaration: { code: 1079, category: DiagnosticCategory.Error, key: "A '{0}' modifier cannot be used with an import declaration." },
         Invalid_reference_directive_syntax: { code: 1084, category: DiagnosticCategory.Error, key: "Invalid 'reference' directive syntax." },
         Octal_literals_are_not_available_when_targeting_ECMAScript_5_and_higher: { code: 1085, category: DiagnosticCategory.Error, key: "Octal literals are not available when targeting ECMAScript 5 and higher." },
         An_accessor_cannot_be_declared_in_an_ambient_context: { code: 1086, category: DiagnosticCategory.Error, key: "An accessor cannot be declared in an ambient context." },
@@ -179,6 +190,10 @@ namespace ts {
         An_export_declaration_can_only_be_used_in_a_module: { code: 1233, category: DiagnosticCategory.Error, key: "An export declaration can only be used in a module." },
         An_ambient_module_declaration_is_only_allowed_at_the_top_level_in_a_file: { code: 1234, category: DiagnosticCategory.Error, key: "An ambient module declaration is only allowed at the top level in a file." },
         A_namespace_declaration_is_only_allowed_in_a_namespace_or_module: { code: 1235, category: DiagnosticCategory.Error, key: "A namespace declaration is only allowed in a namespace or module." },
+        Experimental_support_for_async_functions_is_a_feature_that_is_subject_to_change_in_a_future_release_Specify_experimentalAsyncFunctions_to_remove_this_warning: { code: 1236, category: DiagnosticCategory.Error, key: "Experimental support for async functions is a feature that is subject to change in a future release. Specify '--experimentalAsyncFunctions' to remove this warning." },
+        with_statements_are_not_allowed_in_an_async_function_block: { code: 1300, category: DiagnosticCategory.Error, key: "'with' statements are not allowed in an async function block." },
+        await_expression_is_only_allowed_within_an_async_function: { code: 1308, category: DiagnosticCategory.Error, key: "'await' expression is only allowed within an async function." },
+        Async_functions_are_only_available_when_targeting_ECMAScript_6_and_higher: { code: 1311, category: DiagnosticCategory.Error, key: "Async functions are only available when targeting ECMAScript 6 and higher." },
         The_return_type_of_a_property_decorator_function_must_be_either_void_or_any: { code: 1236, category: DiagnosticCategory.Error, key: "The return type of a property decorator function must be either 'void' or 'any'." },
         The_return_type_of_a_parameter_decorator_function_must_be_either_void_or_any: { code: 1237, category: DiagnosticCategory.Error, key: "The return type of a parameter decorator function must be either 'void' or 'any'." },
         Unable_to_resolve_signature_of_class_decorator_when_called_as_an_expression: { code: 1238, category: DiagnosticCategory.Error, key: "Unable to resolve signature of class decorator when called as an expression." },
@@ -382,6 +397,11 @@ namespace ts {
         No_base_constructor_has_the_specified_number_of_type_arguments: { code: 2508, category: DiagnosticCategory.Error, key: "No base constructor has the specified number of type arguments." },
         Base_constructor_return_type_0_is_not_a_class_or_interface_type: { code: 2509, category: DiagnosticCategory.Error, key: "Base constructor return type '{0}' is not a class or interface type." },
         Base_constructors_must_all_have_the_same_return_type: { code: 2510, category: DiagnosticCategory.Error, key: "Base constructors must all have the same return type." },
+        Duplicate_identifier_0_Compiler_uses_declaration_1_to_support_async_functions: { code: 2520, category: DiagnosticCategory.Error, key: "Duplicate identifier '{0}'. Compiler uses declaration '{1}' to support async functions." },
+        Expression_resolves_to_variable_declaration_0_that_compiler_uses_to_support_async_functions: { code: 2521, category: DiagnosticCategory.Error, key: "Expression resolves to variable declaration '{0}' that compiler uses to support async functions." },
+        The_arguments_object_cannot_be_referenced_in_an_async_arrow_function_Consider_using_a_standard_async_function_expression: { code: 2522, category: DiagnosticCategory.Error, key: "The 'arguments' object cannot be referenced in an async arrow function. Consider using a standard async function expression." },
+        yield_expressions_cannot_be_used_in_a_parameter_initializer: { code: 2523, category: DiagnosticCategory.Error, key: "'yield' expressions cannot be used in a parameter initializer." },
+        await_expressions_cannot_be_used_in_a_parameter_initializer: { code: 2524, category: DiagnosticCategory.Error, key: "'await' expressions cannot be used in a parameter initializer." },
         JSX_element_attributes_type_0_must_be_an_object_type: { code: 2600, category: DiagnosticCategory.Error, key: "JSX element attributes type '{0}' must be an object type." },
         The_return_type_of_a_JSX_element_constructor_must_return_an_object_type: { code: 2601, category: DiagnosticCategory.Error, key: "The return type of a JSX element constructor must return an object type." },
         JSX_element_implicitly_has_type_any_because_the_global_type_JSX_Element_does_not_exist: { code: 2602, category: DiagnosticCategory.Error, key: "JSX element implicitly has type 'any' because the global type 'JSX.Element' does not exist." },
@@ -538,6 +558,8 @@ namespace ts {
         Option_experimentalDecorators_must_also_be_specified_when_option_emitDecoratorMetadata_is_specified: { code: 6064, category: DiagnosticCategory.Error, key: "Option 'experimentalDecorators' must also be specified when option 'emitDecoratorMetadata' is specified." },
         Enables_experimental_support_for_ES7_decorators: { code: 6065, category: DiagnosticCategory.Message, key: "Enables experimental support for ES7 decorators." },
         Enables_experimental_support_for_emitting_type_metadata_for_decorators: { code: 6066, category: DiagnosticCategory.Message, key: "Enables experimental support for emitting type metadata for decorators." },
+        Option_experimentalAsyncFunctions_cannot_be_specified_when_targeting_ES5_or_lower: { code: 6067, category: DiagnosticCategory.Message, key: "Option 'experimentalAsyncFunctions' cannot be specified when targeting ES5 or lower." },
+        Enables_experimental_support_for_ES7_async_functions: { code: 6068, category: DiagnosticCategory.Message, key: "Enables experimental support for ES7 async functions." },
         Variable_0_implicitly_has_an_1_type: { code: 7005, category: DiagnosticCategory.Error, key: "Variable '{0}' implicitly has an '{1}' type." },
         Parameter_0_implicitly_has_an_1_type: { code: 7006, category: DiagnosticCategory.Error, key: "Parameter '{0}' implicitly has an '{1}' type." },
         Member_0_implicitly_has_an_1_type: { code: 7008, category: DiagnosticCategory.Error, key: "Member '{0}' implicitly has an '{1}' type." },

Diff for: src/compiler/diagnosticInformationMap.generated.ts

@@ -103,10 +103,30 @@
         "category": "Error",
         "code": 1039
     },
+    "'{0}' modifier cannot be used in an ambient context.": {
+        "category": "Error",
+        "code": 1040
+    },
+    "'{0}' modifier cannot be used with a class declaration.": {
+        "category": "Error",
+        "code": 1041
+    },
+    "'{0}' modifier cannot be used here.": {
+        "category": "Error",
+        "code": 1042
+    },
+    "'{0}' modifier cannot appear on a data property.": {
+        "category": "Error",
+        "code": 1043
+    },
     "'{0}' modifier cannot appear on a module element.": {
         "category": "Error",
         "code": 1044
     },
+    "A '{0}' modifier cannot be used with an interface declaration.": {
+        "category": "Error",
+        "code": 1045
+    },
     "A 'declare' modifier is required for a top level declaration in a .d.ts file.": {
         "category": "Error",
         "code": 1046
@@ -139,14 +159,38 @@
         "category": "Error",
         "code": 1054
     },
+    "Type '{0}' is not a valid async function return type.": {
+        "category": "Error",
+        "code": 1055  
+    },
     "Accessors are only available when targeting ECMAScript 5 and higher.": {
         "category": "Error",
         "code": 1056
     },
+    "An async function or method must have a valid awaitable return type.": {
+        "category": "Error",
+        "code": 1057
+    },
+    "Operand for 'await' does not have a valid callable 'then' member.": {
+        "category": "Error",
+        "code": 1058
+    },
+    "Return expression in async function does not have a valid callable 'then' member.": {
+        "category": "Error",
+        "code": 1059
+    },
+    "Expression body for async arrow function does not have a valid callable 'then' member.": {
+        "category": "Error",
+        "code": 1060
+    },
     "Enum member must have initializer.": {
         "category": "Error",
         "code": 1061
     },
+    "{0} is referenced directly or indirectly in the fulfillment callback of its own 'then' method.": {
+        "category": "Error",
+        "code": 1062
+    },
     "An export assignment cannot be used in a namespace.": {
         "category": "Error",
         "code": 1063
@@ -159,7 +203,7 @@
         "category": "Error",
         "code": 1068
     },
-    "A 'declare' modifier cannot be used with an import declaration.": {
+    "A '{0}' modifier cannot be used with an import declaration.": {
         "category": "Error",
         "code": 1079
     },
@@ -703,7 +747,24 @@
         "category": "Error",
         "code": 1235
     },
+    "Experimental support for async functions is a feature that is subject to change in a future release. Specify '--experimentalAsyncFunctions' to remove this warning.": {
+        "category": "Error",
+        "code": 1236
+    },
+
 
+    "'with' statements are not allowed in an async function block.": {
+        "category": "Error",
+        "code": 1300
+    },
+    "'await' expression is only allowed within an async function.": {
+        "category": "Error",
+        "code": 1308
+    },
+    "Async functions are only available when targeting ECMAScript 6 and higher.": {
+        "category": "Error",
+        "code": 1311
+    },
 
     "The return type of a property decorator function must be either 'void' or 'any'.": {
         "category": "Error",
@@ -1519,6 +1580,27 @@
         "code": 2510
     },
 
+    "Duplicate identifier '{0}'. Compiler uses declaration '{1}' to support async functions.": {
+        "category": "Error",
+        "code": 2520
+    },
+    "Expression resolves to variable declaration '{0}' that compiler uses to support async functions.": {
+        "category": "Error",
+        "code": 2521
+    },
+    "The 'arguments' object cannot be referenced in an async arrow function. Consider using a standard async function expression.": {
+        "category": "Error",
+        "code": 2522
+    },
+    "'yield' expressions cannot be used in a parameter initializer.": {
+        "category": "Error",
+        "code": 2523
+    },
+    "'await' expressions cannot be used in a parameter initializer.": {
+        "category": "Error",
+        "code": 2524
+    },
+
     "JSX element attributes type '{0}' must be an object type.": {
         "category": "Error",
         "code": 2600
@@ -2145,6 +2227,14 @@
         "category": "Message",
         "code": 6066
     },
+    "Option 'experimentalAsyncFunctions' cannot be specified when targeting ES5 or lower.": {
+        "category": "Message",
+        "code": 6067
+    },
+    "Enables experimental support for ES7 async functions.": {
+        "category": "Message",
+        "code": 6068
+    },
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",