microsoft · rbuckton · Jun 24, 2015 · May 21, 2015 · May 23, 2015 · May 27, 2015
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
@@ -191,6 +191,12 @@ 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." },
+        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." },
+        Unable_to_resolve_signature_of_parameter_decorator_when_called_as_an_expression: { code: 1239, category: DiagnosticCategory.Error, key: "Unable to resolve signature of parameter decorator when called as an expression." },
+        Unable_to_resolve_signature_of_property_decorator_when_called_as_an_expression: { code: 1240, category: DiagnosticCategory.Error, key: "Unable to resolve signature of property decorator when called as an expression." },
+        Unable_to_resolve_signature_of_method_decorator_when_called_as_an_expression: { code: 1241, category: DiagnosticCategory.Error, key: "Unable to resolve signature of method decorator when called as an expression." },
         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." },

diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
@@ -753,6 +753,31 @@
     },
 
 
+    "The return type of a property decorator function must be either 'void' or 'any'.": {
+        "category": "Error",
+        "code": 1236
+    },
+    "The return type of a parameter decorator function must be either 'void' or 'any'.": {
+        "category": "Error",
+        "code": 1237
+    },
+    "Unable to resolve signature of class decorator when called as an expression.": {
+        "category": "Error",
+        "code": 1238
+    },
+    "Unable to resolve signature of parameter decorator when called as an expression.": {
+        "category": "Error",
+        "code": 1239
+    },
+    "Unable to resolve signature of property decorator when called as an expression.": {
+        "category": "Error",
+        "code": 1240
+    },
+    "Unable to resolve signature of method decorator when called as an expression.": {
+        "category": "Error",
+        "code": 1241
+    },
+
     "Duplicate identifier '{0}'.": {
         "category": "Error",
         "code": 2300

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -797,7 +797,7 @@ namespace ts {
         template: LiteralExpression | TemplateExpression;
     }
 
-    export type CallLikeExpression = CallExpression | NewExpression | TaggedTemplateExpression;
+    export type CallLikeExpression = CallExpression | NewExpression | TaggedTemplateExpression | Decorator;
 
     export interface TypeAssertion extends UnaryExpression {
         type: TypeNode;

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -754,8 +754,8 @@ namespace ts {
             return (<TaggedTemplateExpression>node).tag;
         }
 
-        // Will either be a CallExpression or NewExpression.
-        return (<CallExpression>node).expression;
+        // Will either be a CallExpression, NewExpression, or Decorator.
+        return (<CallExpression | Decorator>node).expression;
     }
 
     export function nodeCanBeDecorated(node: Node): boolean {

diff --git a/tests/baselines/reference/decoratedClassFromExternalModule.js b/tests/baselines/reference/decoratedClassFromExternalModule.js
@@ -1,7 +1,7 @@
 //// [tests/cases/conformance/decorators/class/decoratedClassFromExternalModule.ts] ////
 
 //// [decorated.ts]
-function decorate() { }
+function decorate(target: any) { }
 
 @decorate
 export default class Decorated { }
@@ -18,7 +18,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
         case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, desc);
     }
 };
-function decorate() { }
+function decorate(target) { }
 let Decorated = class {
 };
 Decorated = __decorate([

diff --git a/tests/baselines/reference/decoratedClassFromExternalModule.symbols b/tests/baselines/reference/decoratedClassFromExternalModule.symbols
@@ -1,12 +1,13 @@
 === tests/cases/conformance/decorators/class/decorated.ts ===
-function decorate() { }
+function decorate(target: any) { }
 >decorate : Symbol(decorate, Decl(decorated.ts, 0, 0))
+>target : Symbol(target, Decl(decorated.ts, 0, 18))
 
 @decorate
 >decorate : Symbol(decorate, Decl(decorated.ts, 0, 0))
 
 export default class Decorated { }
->Decorated : Symbol(Decorated, Decl(decorated.ts, 0, 23))
+>Decorated : Symbol(Decorated, Decl(decorated.ts, 0, 34))
 
 === tests/cases/conformance/decorators/class/undecorated.ts ===
 import Decorated from 'decorated';

diff --git a/tests/baselines/reference/decoratedClassFromExternalModule.types b/tests/baselines/reference/decoratedClassFromExternalModule.types
@@ -1,9 +1,10 @@
 === tests/cases/conformance/decorators/class/decorated.ts ===
-function decorate() { }
->decorate : () => void
+function decorate(target: any) { }
+>decorate : (target: any) => void
+>target : any
 
 @decorate
->decorate : () => void
+>decorate : (target: any) => void
 
 export default class Decorated { }
 >Decorated : Decorated

diff --git a/tests/baselines/reference/decoratorChecksFunctionBodies.errors.txt b/tests/baselines/reference/decoratorChecksFunctionBodies.errors.txt
@@ -8,7 +8,7 @@ tests/cases/conformance/decorators/class/decoratorChecksFunctionBodies.ts(9,14):
     }
 
     class A {
-        @(x => {
+        @((x, p) => {
             var a = 3;
             func(a);
                  ~

diff --git a/tests/baselines/reference/decoratorChecksFunctionBodies.js b/tests/baselines/reference/decoratorChecksFunctionBodies.js
@@ -5,7 +5,7 @@ function func(s: string): void {
 }
 
 class A {
-    @(x => {
+    @((x, p) => {
         var a = 3;
         func(a);
         return x; 
@@ -34,7 +34,7 @@ var A = (function () {
     };
     Object.defineProperty(A.prototype, "m",
         __decorate([
-            (function (x) {
+            (function (x, p) {
                 var a = 3;
                 func(a);
                 return x;

diff --git a/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.js b/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.js
@@ -9,7 +9,7 @@ export var test = 'abc';
 import { test } from './a';
 
 function filter(handler: any) {
-    return function (target: any) {
+    return function (target: any, propertyKey: string) {
         // ...
     };
 }
@@ -35,7 +35,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 };
 var a_1 = require('./a');
 function filter(handler) {
-    return function (target) {
+    return function (target, propertyKey) {
         // ...
     };
 }

diff --git a/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.symbols b/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.symbols
@@ -12,8 +12,9 @@ function filter(handler: any) {
 >filter : Symbol(filter, Decl(b.ts, 0, 27))
 >handler : Symbol(handler, Decl(b.ts, 2, 16))
 
-    return function (target: any) {
+    return function (target: any, propertyKey: string) {
 >target : Symbol(target, Decl(b.ts, 3, 21))
+>propertyKey : Symbol(propertyKey, Decl(b.ts, 3, 33))
 
         // ...
     };

diff --git a/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.types b/tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.types
@@ -10,12 +10,13 @@ import { test } from './a';
 >test : string
 
 function filter(handler: any) {
->filter : (handler: any) => (target: any) => void
+>filter : (handler: any) => (target: any, propertyKey: string) => void
 >handler : any
 
-    return function (target: any) {
->function (target: any) {        // ...    } : (target: any) => void
+    return function (target: any, propertyKey: string) {
+>function (target: any, propertyKey: string) {        // ...    } : (target: any, propertyKey: string) => void
 >target : any
+>propertyKey : string
 
         // ...
     };
@@ -25,8 +26,8 @@ class Wat {
 >Wat : Wat
 
     @filter(() => test == 'abc')
->filter(() => test == 'abc') : (target: any) => void
->filter : (handler: any) => (target: any) => void
+>filter(() => test == 'abc') : (target: any, propertyKey: string) => void
+>filter : (handler: any) => (target: any, propertyKey: string) => void
 >() => test == 'abc' : () => boolean
 >test == 'abc' : boolean
 >test : string

diff --git a/tests/baselines/reference/decoratorOnClass8.errors.txt b/tests/baselines/reference/decoratorOnClass8.errors.txt
@@ -1,11 +1,13 @@
-tests/cases/conformance/decorators/class/decoratorOnClass8.ts(3,1): error TS2322: Type '(target: Function, paramIndex: number) => void' is not assignable to type '(target: typeof C) => void | typeof C'.
+tests/cases/conformance/decorators/class/decoratorOnClass8.ts(3,1): error TS1238: Unable to resolve signature of class decorator when called as an expression.
+  Supplied parameters do not match any signature of call target.
 
 
 ==== tests/cases/conformance/decorators/class/decoratorOnClass8.ts (1 errors) ====
     declare function dec(): (target: Function, paramIndex: number) => void;
 
     @dec()
     ~~~~~~
-!!! error TS2322: Type '(target: Function, paramIndex: number) => void' is not assignable to type '(target: typeof C) => void | typeof C'.
+!!! error TS1238: Unable to resolve signature of class decorator when called as an expression.
+!!! error TS1238:   Supplied parameters do not match any signature of call target.
     class C {
     }
diff --git a/tests/baselines/reference/decoratorOnClassMethod10.errors.txt b/tests/baselines/reference/decoratorOnClassMethod10.errors.txt
@@ -1,17 +1,13 @@
-tests/cases/conformance/decorators/class/method/decoratorOnClassMethod10.ts(4,5): error TS2322: Type '(target: Function, paramIndex: number) => void' is not assignable to type '(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<() => void>) => void | TypedPropertyDescriptor<() => void>'.
-  Types of parameters 'paramIndex' and 'propertyKey' are incompatible.
-    Type 'number' is not assignable to type 'string | symbol'.
-      Type 'number' is not assignable to type 'symbol'.
+tests/cases/conformance/decorators/class/method/decoratorOnClassMethod10.ts(4,6): error TS2345: Argument of type 'C' is not assignable to parameter of type 'Function'.
+  Property 'apply' is missing in type 'C'.
 
 
 ==== tests/cases/conformance/decorators/class/method/decoratorOnClassMethod10.ts (1 errors) ====
     declare function dec(target: Function, paramIndex: number): void;
 
     class C {
         @dec method() {}
-        ~~~~
-!!! error TS2322: Type '(target: Function, paramIndex: number) => void' is not assignable to type '(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<() => void>) => void | TypedPropertyDescriptor<() => void>'.
-!!! error TS2322:   Types of parameters 'paramIndex' and 'propertyKey' are incompatible.
-!!! error TS2322:     Type 'number' is not assignable to type 'string | symbol'.
-!!! error TS2322:       Type 'number' is not assignable to type 'symbol'.
+         ~~~
+!!! error TS2345: Argument of type 'C' is not assignable to parameter of type 'Function'.
+!!! error TS2345:   Property 'apply' is missing in type 'C'.
     }
diff --git a/tests/baselines/reference/decoratorOnClassMethod13.js b/tests/baselines/reference/decoratorOnClassMethod13.js
@@ -1,5 +1,5 @@
 //// [decoratorOnClassMethod13.ts]
-declare function dec(): <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>;
+declare function dec<T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>): TypedPropertyDescriptor<T>;
 
 class C {
     @dec ["1"]() { }

diff --git a/tests/baselines/reference/decoratorOnClassMethod13.symbols b/tests/baselines/reference/decoratorOnClassMethod13.symbols
@@ -1,17 +1,17 @@
 === tests/cases/conformance/decorators/class/method/decoratorOnClassMethod13.ts ===
-declare function dec(): <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>;
+declare function dec<T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>): TypedPropertyDescriptor<T>;
 >dec : Symbol(dec, Decl(decoratorOnClassMethod13.ts, 0, 0))
->T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 25))
->target : Symbol(target, Decl(decoratorOnClassMethod13.ts, 0, 28))
->propertyKey : Symbol(propertyKey, Decl(decoratorOnClassMethod13.ts, 0, 40))
->descriptor : Symbol(descriptor, Decl(decoratorOnClassMethod13.ts, 0, 61))
+>T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 21))
+>target : Symbol(target, Decl(decoratorOnClassMethod13.ts, 0, 24))
+>propertyKey : Symbol(propertyKey, Decl(decoratorOnClassMethod13.ts, 0, 36))
+>descriptor : Symbol(descriptor, Decl(decoratorOnClassMethod13.ts, 0, 57))
 >TypedPropertyDescriptor : Symbol(TypedPropertyDescriptor, Decl(lib.d.ts, 1171, 36))
->T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 25))
+>T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 21))
 >TypedPropertyDescriptor : Symbol(TypedPropertyDescriptor, Decl(lib.d.ts, 1171, 36))
->T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 25))
+>T : Symbol(T, Decl(decoratorOnClassMethod13.ts, 0, 21))
 
 class C {
->C : Symbol(C, Decl(decoratorOnClassMethod13.ts, 0, 132))
+>C : Symbol(C, Decl(decoratorOnClassMethod13.ts, 0, 126))
 
     @dec ["1"]() { }
 >dec : Symbol(dec, Decl(decoratorOnClassMethod13.ts, 0, 0))

diff --git a/tests/baselines/reference/decoratorOnClassMethod13.types b/tests/baselines/reference/decoratorOnClassMethod13.types
@@ -1,6 +1,6 @@
 === tests/cases/conformance/decorators/class/method/decoratorOnClassMethod13.ts ===
-declare function dec(): <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>;
->dec : () => <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
+declare function dec<T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>): TypedPropertyDescriptor<T>;
+>dec : <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
 >T : T
 >target : any
 >propertyKey : string
@@ -14,10 +14,10 @@ class C {
 >C : C
 
     @dec ["1"]() { }
->dec : () => <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
+>dec : <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
 >"1" : string
 
     @dec ["b"]() { }
->dec : () => <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
+>dec : <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>
 >"b" : string
 }
diff --git a/tests/baselines/reference/decoratorOnClassMethod6.errors.txt b/tests/baselines/reference/decoratorOnClassMethod6.errors.txt
@@ -0,0 +1,13 @@
+tests/cases/conformance/decorators/class/method/decoratorOnClassMethod6.ts(4,5): error TS1241: Unable to resolve signature of method decorator when called as an expression.
+  Supplied parameters do not match any signature of call target.
+
+
+==== tests/cases/conformance/decorators/class/method/decoratorOnClassMethod6.ts (1 errors) ====
+    declare function dec(): <T>(target: any, propertyKey: string, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T>;
+
+    class C {
+        @dec ["method"]() {}
+        ~~~~
+!!! error TS1241: Unable to resolve signature of method decorator when called as an expression.
+!!! error TS1241:   Supplied parameters do not match any signature of call target.
+    }
diff --git a/tests/baselines/reference/decoratorOnClassMethod6.symbols b/tests/baselines/reference/decoratorOnClassMethod6.symbols
diff --git a/tests/baselines/reference/decoratorOnClassMethod6.types b/tests/baselines/reference/decoratorOnClassMethod6.types
diff --git a/tests/baselines/reference/decoratorOnClassMethod8.errors.txt b/tests/baselines/reference/decoratorOnClassMethod8.errors.txt
@@ -0,0 +1,13 @@
+tests/cases/conformance/decorators/class/method/decoratorOnClassMethod8.ts(4,5): error TS1241: Unable to resolve signature of method decorator when called as an expression.
+  Supplied parameters do not match any signature of call target.
+
+
+==== tests/cases/conformance/decorators/class/method/decoratorOnClassMethod8.ts (1 errors) ====
+    declare function dec<T>(target: T): T;
+
+    class C {
+        @dec method() {}
+        ~~~~
+!!! error TS1241: Unable to resolve signature of method decorator when called as an expression.
+!!! error TS1241:   Supplied parameters do not match any signature of call target.
+    }
diff --git a/tests/baselines/reference/decoratorOnClassMethod8.symbols b/tests/baselines/reference/decoratorOnClassMethod8.symbols
diff --git a/tests/baselines/reference/decoratorOnClassMethod8.types b/tests/baselines/reference/decoratorOnClassMethod8.types