[ref-struct]: add opt parameter to allow create packed struct (#21932)

* [ref-struct]: add opt parameter to allow create packed struct

* Set TypeScript version to 2.2 for package depending on ref-struct

types/ffi/index.d.ts

@@ -2,6 +2,7 @@
 // Project: https://github.com/rbranson/node-ffi
 // Definitions by: Paul Loyd <https://github.com/loyd>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.2
 
 /// <reference types="node" />
 

types/ref-struct/index.d.ts

@@ -2,6 +2,7 @@
 // Project: https://github.com/TooTallNate/ref-struct
 // Definitions by: Paul Loyd <https://github.com/loyd>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.2
 
 import ref = require('ref');
 
@@ -50,9 +51,9 @@ interface StructType extends ref.Type {
 
 /** The struct type meta-constructor. */
 declare var StructType: {
-    new (fields?: {}): StructType;
+    new (fields?: object, opt?: object): StructType;
     new (fields?: any[]): StructType;
-    (fields?: {}): StructType;
+    (fields?: object, opt?: object): StructType;
     (fields?: any[]): StructType;
 }
 

types/ref-struct/ref-struct-tests.ts

@@ -0,0 +1,12 @@
+import ref = require("ref");
+import StructType = require("ref-struct");
+
+const normalStruct = StructType({
+  t: ref.types.uint8,
+  v: ref.types.long,
+});
+
+const packedStruct = StructType({
+  t: ref.types.uint8,
+  v: ref.types.long,
+}, {packed: true});

types/ref-struct/tsconfig.json

@@ -17,6 +17,7 @@
         "forceConsistentCasingInFileNames": true
     },
     "files": [
-        "index.d.ts"
+        "index.d.ts",
+        "ref-struct-tests.ts"
     ]
 }