Fix Node.js 12 compatibility (#58)

.travis.yml

@@ -5,6 +5,7 @@ dist: bionic
 services:
   - xvfb
 node_js:
+  - '12'
   - '10'
   - '8'
 before_install:

lib/windows.js

@@ -2,9 +2,9 @@
 'use strict';
 const path = require('path');
 const ffi = require('ffi-napi');
-const wchar = require('ref-wchar');
-const ref = require('ref');
-const struct = require('ref-struct');
+const wchar = require('ref-wchar-napi');
+const ref = require('ref-napi');
+const struct = require('ref-struct-napi');
 
 // Create the struct required to save the window bounds
 const Rect = struct({
@@ -82,7 +82,7 @@ function windows() {
 	const windowId = ref.address(activeWindowHandle);
 	// Get the window text length in "characters" to create the buffer
 	const windowTextLength = user32.GetWindowTextLengthW(activeWindowHandle);
-	// Allocate a buffer large enough to hold the window text as "Unicode" (UTF-16) characters (using ref-wchar)
+	// Allocate a buffer large enough to hold the window text as "Unicode" (UTF-16) characters (using ref-wchar-napi)
 	// This assumes using the "Basic Multilingual Plane" of Unicode, only 2 characters per Unicode code point
 	// Include some extra bytes for possible null characters
 	const windowTextBuffer = Buffer.alloc((windowTextLength * 2) + 4);

package.json

@@ -53,8 +53,8 @@
 	},
 	"optionalDependencies": {
 		"ffi-napi": "^2.4.5",
-		"ref": "^1.3.5",
-		"ref-wchar": "^1.0.2",
-		"ref-struct": "^1.1.0"
+		"ref-napi": "^1.4.2",
+		"ref-wchar-napi": "^1.0.2",
+		"ref-struct-napi": "^1.1.0"
 	}
 }