options.text validation

warpcast.ts

@@ -11,29 +11,43 @@ interface WarpcastComposeOptions {
 const hashPattern = /^0x[a-fA-F0-9]{40}$/; // regex pattern for hash validation
 
 /**
- * Methods to generate a Warpcast composer URL with the given options,
- * docs at https://docs.farcaster.xyz/reference/warpcast/cast-composer-intents
+ * Methods to generate a Warpcast composer intent URL with options,
+ * as described in the docs at https://docs.farcaster.xyz/reference/warpcast/cast-composer-intents
  *
  */
 export class WarpcastUrlBuilder {
   private static readonly COMPOSER_BASE_URL = 'https://warpcast.com/~/compose';
 
   /**
    * @param options.text - The text of the cast
+   * - max 320 characters for short casts
+   * - max 1024 characters for long casts
    *
-   * @param options.embeds - The embeds to include in the cast (max 2), must be valid URLs
+   * @param options.embeds - The embed URLs to include in the cast
+   * - max 2
+   * - must be valid URLs
    *
    * @param options.parentCastHash - The parent cast hash for replies,
-   * `/^0x[a-fA-F0-9]{40}$/`,
-   * overrides `options.channelKey`
+   * - must be in valid hash format `/^0x[a-fA-F0-9]{40}$/`
+   * - overrides `options.channelKey`
    *
-   * @param options.channelKey - The name of the channel to post to
+   * @param options.channelKey - The name of the channel to cast into
    *
-   * @returns The composer URL
+   * @returns The Warpcast intent URL
    */
   static composerUrl(options: WarpcastComposeOptions): string {
     const params = new URLSearchParams();
 
+    if (options.text.length > 1024) {
+      throw new Error(
+        'Farcaster does not support cast text longer than 1024 characters'
+      );
+    }
+    if (options.text.length > 320) {
+      console.warn(
+        'This is a long cast. It will show only the first 320 characters on timeline'
+      );
+    }
     params.append('text', options.text);
 
     if (options.embeds?.length) {
@@ -59,7 +73,7 @@ export class WarpcastUrlBuilder {
 
     if (options.parentCastHash) {
       if (!hashPattern.test(options.parentCastHash)) {
-        throw new Error('Invalid parent cast hash');
+        throw new Error('Invalid parent cast hash format');
       }
       params.append('parentCastHash', options.parentCastHash);
     }