Add InviteResolvable (#766)

* Add InviteResolvable

Add InviteResolvable

* Return data as fallback instead

* Rename resolver method

src/client/Client.js

@@ -265,10 +265,11 @@ class Client extends EventEmitter {
 
   /**
    * Fetches an invite object from an invite code.
-   * @param {string} code the invite code.
+   * @param {InviteResolvable} invite An invite code or URL
    * @returns {Promise<Invite>}
    */
-  fetchInvite(code) {
+  fetchInvite(invite) {
+    const code = this.resolver.resolveInviteCode(invite);
     return this.rest.methods.getInvite(code);
   }
 

src/client/ClientDataResolver.js

@@ -205,6 +205,26 @@ class ClientDataResolver {
     return String(data);
   }
 
+  /**
+   * Data that can be resolved to give an invite code. This can be:
+   * * An invite code
+   * * An invite URL
+   * @typedef {string} InviteResolvable
+   */
+
+  /**
+   * Resolves InviteResolvable to an invite code
+   * @param {InviteResolvable} data The invite resolvable to resolve
+   * @returns {string}
+   */
+  resolveInviteCode(data) {
+    const inviteRegex = /discord(?:app)?\.(?:gg|com\/invite)\/([a-z0-9]{5})/i;
+    const match = inviteRegex.exec(data);
+
+    if (match && match[1]) return match[1];
+    return data;
+  }
+
   /**
    * Data that can be resolved to give a Buffer. This can be:
    * * A Buffer