test: add baseline tests for _tools/licenses/licenses and add README example

PR-URL: #12273
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: Planeshifter

lib/node_modules/@stdlib/_tools/licenses/licenses/README.md

@@ -97,11 +97,22 @@ function onResults( error, results ) {
 
 <section class="examples">
 
-<!-- ## Examples
+## Examples
 
-``` javascript
+<!-- eslint no-undef: "error" -->
 
-``` -->
+```javascript
+var licenses = require( '@stdlib/_tools/licenses/licenses' );
+
+licenses( onResults );
+
+function onResults( error, results ) {
+    if ( error ) {
+        throw error;
+    }
+    console.log( JSON.stringify( results ) );
+}
+```
 
 </section>
 

lib/node_modules/@stdlib/_tools/licenses/licenses/package.json

@@ -20,7 +20,8 @@
   "directories": {
     "doc": "./docs",
     "example": "./examples",
-    "lib": "./lib"
+    "lib": "./lib",
+    "test": "./test"
   },
   "scripts": {},
   "homepage": "https://github.com/stdlib-js/stdlib",

lib/node_modules/@stdlib/_tools/licenses/licenses/test/test.js

@@ -0,0 +1,61 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var tape = require( 'tape' );
+var licenses = require( './../lib' );
+
+
+// TESTS //
+
+tape( 'main export is a function', function test( t ) {
+	t.ok( true, __filename );
+	t.strictEqual( typeof licenses, 'function', 'main export is a function' );
+	t.end();
+});
+
+tape( 'the function throws an error if not provided a callback argument which is a function', function test( t ) {
+	var values;
+	var i;
+
+	values = [
+		'5',
+		5,
+		NaN,
+		true,
+		false,
+		null,
+		undefined,
+		[],
+		{}
+	];
+
+	for ( i = 0; i < values.length; i++ ) {
+		t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided '+values[ i ] );
+	}
+	t.end();
+
+	function badValue( value ) {
+		return function badValue() {
+			licenses( value );
+		};
+	}
+});