fix: update the copy for the default fallbacks

packages/content-type-reaction/src/Reaction.ts

@@ -72,7 +72,14 @@ export class ReactionCodec implements ContentCodec<Reaction> {
     };
   }
 
-  fallback(): string | undefined {
-    return "Error: Sorry, this app cannot display reactions";
+  fallback(content: Reaction): string | undefined {
+    switch (content.action) {
+      case "added":
+        return `Reacted “${content.content}” to an earlier message`;
+      case "removed":
+        return `Removed “${content.content}” from an earlier message`;
+      default:
+        return undefined;
+    }  
   }
 }

packages/content-type-read-receipt/src/ReadReceipt.ts

@@ -40,7 +40,7 @@ export class ReadReceiptCodec implements ContentCodec<ReadReceipt> {
     };
   }
 
-  fallback(): string | undefined {
+  fallback(content: ReadReceipt): string | undefined {
     return undefined;
   }
 }

packages/content-type-remote-attachment/src/Attachment.ts

@@ -38,7 +38,7 @@ export class AttachmentCodec implements ContentCodec<Attachment> {
     };
   }
 
-  fallback(): string | undefined {
-    return "Error: Sorry, this app cannot display attachments";
+  fallback(content: Attachment): string | undefined {
+    return `Can’t display "${content.filename}". This app doesn’t support attachments.`;
   }
 }

packages/content-type-remote-attachment/src/RemoteAttachment.ts

@@ -162,7 +162,7 @@ export class RemoteAttachmentCodec implements ContentCodec<RemoteAttachment> {
     };
   }
 
-  fallback(): string | undefined {
-    return "Error: Sorry, this app cannot display attachments";
+  fallback(content: RemoteAttachment): string | undefined {
+    return `Can’t display "${content.filename}". This app doesn’t support attachments.`;
   }
 }

packages/content-type-reply/src/Reply.ts

@@ -76,7 +76,7 @@ export class ReplyCodec implements ContentCodec<Reply> {
     };
   }
 
-  fallback(): string | undefined {
-    return "Error: Sorry, this app cannot display quote replies";
+  fallback(content: Reply): string | undefined {
+    return `Replied with “${content.content}” to an earlier message`;
   }
 }