test: add test for --packages flag

tests/packages-test.js

@@ -0,0 +1,23 @@
+var assert = require('assert'),
+    path = require('path'),
+    spawn = require('child_process').spawn,
+    restrictedPackages = [
+        '[email protected]',
+        '[email protected]',
+        '[email protected]',
+    ];
+
+describe('bin/license-checker', function() {
+    this.timeout(8000);
+
+    it('should restrict the output to the provided packages', function(done) {
+        var node = spawn('node', [path.join(__dirname, '../bin/license-checker'), '--json', '--packages', restrictedPackages.join(';')], {
+            cwd: path.join(__dirname, '../'),
+        });
+
+        node.stdout.on('data', function(data) {
+            assert.deepEqual(Object.keys(JSON.parse(data.toString())), restrictedPackages);
+            done();
+        });
+    });
+});