diff --git a/js-beautify/js-beautify-tests.ts b/js-beautify/js-beautify-tests.ts
new file mode 100644
index 000000000..bcd431c2b
--- /dev/null
+++ b/js-beautify/js-beautify-tests.ts
@@ -0,0 +1,28 @@
+/// <reference path="js-beautify.d.ts" />
+
+var simple: string = js_beautify("console.log('Hello world!');");
+
+var full: string = js_beautify(
+    "console.log('Hello world!');",
+    {
+        "indent_size": 4,
+        "indent_char": " ",
+        "eol": "\n",
+        "indent_level": 0,
+        "indent_with_tabs": false,
+        "preserve_newlines": true,
+        "max_preserve_newlines": 10,
+        "jslint_happy": false,
+        "space_after_anon_function": false,
+        "brace_style": "collapse",
+        "keep_array_indentation": false,
+        "keep_function_indentation": false,
+        "space_before_conditional": true,
+        "break_chained_methods": false,
+        "eval_code": false,
+        "unescape_strings": false,
+        "wrap_line_length": 0,
+        "wrap_attributes": "auto",
+        "wrap_attributes_indent_size": 4,
+        "end_with_newline": false
+    });
diff --git a/js-beautify/js-beautify.d.ts b/js-beautify/js-beautify.d.ts
new file mode 100644
index 000000000..e52614ad8
--- /dev/null
+++ b/js-beautify/js-beautify.d.ts
@@ -0,0 +1,29 @@
+// Type definitions for js_beautify
+// Project: https://github.com/beautify-web/js-beautify/
+// Definitions by: Josh Goldberg <https://github.com/JoshuaKGoldberg/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare var js_beautify: {
+    (js_source_text: string, options?: {
+        indent_size?: number;
+        indent_char?: string;
+        eol?: string;
+        indent_level?: number;
+        indent_width_tabs?: boolean;
+        preserve_newlines?: boolean;
+        max_preserve_newlines?: number;
+        jslint_happy: boolean;
+        space_after_anon_function: boolean;
+        brace_style: string;
+        keep_array_indentation: boolean;
+        keep_function_indentation: boolean;
+        space_before_conditional: boolean;
+        break_chained_methods: boolean;
+        eval_code: boolean;
+        unescape_strings: boolean;
+        wrap_line_length: number;
+        wrap_attributes: string;
+        wrap_attributes_indent_size: number;
+        end_with_newline: boolean;
+    }): string;
+};