Chore: introduce eslint to build script

Build/lib/trie.js

@@ -31,6 +31,24 @@ class Trie {
     return this;
   }
 
+  /**
+   * @param {string} suffix
+   */
+  contains(suffix) {
+    let node = this.root;
+    let token;
+
+    for (let i = suffix.length - 1; i >= 0; i--) {
+      token = suffix[i];
+
+      node = node[token];
+
+      if (node == null) return false;
+    }
+
+    return true;
+  }
+
   /**
    * Method used to retrieve every item in the trie with the given prefix.
    *
@@ -42,8 +60,6 @@ class Trie {
     let node = this.root;
     const matches = [];
     let token;
-    let i;
-    let l;
 
     for (let i = suffix.length - 1; i >= 0; i--) {
       token = suffix[i];