Merge pull request #14053 from Microsoft/usePromise

Move `Promise<T>` declaration to `lib.es5.d.ts`

src/compiler/checker.ts

@@ -14358,6 +14358,9 @@ namespace ts {
                 error(func, Diagnostics.An_async_function_or_method_must_return_a_Promise_Make_sure_you_have_a_declaration_for_Promise_or_include_ES2015_in_your_lib_option);
                 return unknownType;
             }
+            else if (!getGlobalPromiseConstructorSymbol()) {
+                error(func, Diagnostics.An_async_function_or_method_in_ES5_SlashES3_requires_the_Promise_constructor_Make_sure_you_have_a_declaration_for_the_Promise_constructor_or_include_ES2015_in_your_lib_option);
+            }
 
             return promiseType;
         }
@@ -16954,7 +16957,12 @@ namespace ts {
                 const promiseConstructorSymbol = resolveEntityName(promiseConstructorName, SymbolFlags.Value, /*ignoreErrors*/ true);
                 const promiseConstructorType = promiseConstructorSymbol ? getTypeOfSymbol(promiseConstructorSymbol) : unknownType;
                 if (promiseConstructorType === unknownType) {
-                    error(node.type, Diagnostics.Type_0_is_not_a_valid_async_function_return_type_in_ES5_SlashES3_because_it_does_not_refer_to_a_Promise_compatible_constructor_value, entityNameToString(promiseConstructorName));
+                    if (promiseConstructorName.kind === SyntaxKind.Identifier && promiseConstructorName.text === "Promise" && getTargetType(returnType) === tryGetGlobalPromiseType()) {
+                        error(node.type, Diagnostics.An_async_function_or_method_in_ES5_SlashES3_requires_the_Promise_constructor_Make_sure_you_have_a_declaration_for_the_Promise_constructor_or_include_ES2015_in_your_lib_option);
+                    }
+                    else {
+                        error(node.type, Diagnostics.Type_0_is_not_a_valid_async_function_return_type_in_ES5_SlashES3_because_it_does_not_refer_to_a_Promise_compatible_constructor_value, entityNameToString(promiseConstructorName));
+                    }
                     return unknownType;
                 }
 

src/compiler/diagnosticMessages.json

@@ -2055,6 +2055,10 @@
         "category": "Error",
         "code": 2704
     },
+    "An async function or method in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your `--lib` option.": {
+        "category": "Error",
+        "code": 2705
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",