fix(stripHTML): should be more strict with non string (#265)

And strip them :)

Author: tomap

lib/strip_html.js

@@ -5,6 +5,11 @@ const STATE_HTML = Symbol('html');
 const STATE_COMMENT = Symbol('comment');
 
 function striptags(html = '') {
+  // if not string, then safely return an empty string
+  if (typeof html !== 'string' && !(html instanceof String)) {
+    return '';
+  }
+
   let state = STATE_PLAINTEXT;
   let tag_buffer = '';
   let depth = 0;

test/strip_html.spec.js

@@ -51,4 +51,11 @@ describe('stripHTML', () => {
 
     stripHTML(html).should.eql(text);
   });
+
+  it('should strip non string parameters', () => {
+    const html = ['X'];
+    const text = '';
+
+    stripHTML(html).should.eql(text);
+  });
 });