Simplify Swift invoice handling with non-optional return types

- Mentions.swift: convert_invoice_description now returns non-optional
  InvoiceDescription, returning empty description for BOLT11 compliance
  (both description and description_hash are optional per spec)

- Block.swift, NdbBlock.swift, NostrEvent.swift, NoteContent.swift:
  Updated call sites to use non-optional invoice conversion

- InvoiceTests.swift: Added test for specific failing invoice

Signed-off-by: alltheseas <alltheseas@noreply.github.com>
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

damus/Core/Nostr/Mentions.swift

@@ -294,7 +294,10 @@ func format_msats(_ msat: Int64, locale: Locale = Locale.current) -> String {
     return String(format: format, locale: locale, sats.decimalValue as NSDecimalNumber, formattedSats)
 }
 
-func convert_invoice_description(b11: ndb_invoice) -> InvoiceDescription? {
+/// Extracts the description from a BOLT11 invoice.
+/// Returns empty description if invoice has neither description nor description_hash,
+/// as both fields are optional per BOLT11 spec.
+func convert_invoice_description(b11: ndb_invoice) -> InvoiceDescription {
     if let desc = b11.description {
         return .description(String(cString: desc))
     }
@@ -303,7 +306,7 @@ func convert_invoice_description(b11: ndb_invoice) -> InvoiceDescription? {
         return .description_hash(Data(bytes: &deschash, count: 32))
     }
 
-    return nil
+    return .description("")
 }
 
 func find_tag_ref(type: String, id: String, tags: [[String]]) -> Int? {

damus/Core/Nostr/NostrEvent.swift

@@ -839,9 +839,7 @@ func separate_invoices(ndb: Ndb, ev: NostrEvent, keypair: Keypair) -> [Invoice]?
         let invoiceBlocks: [Invoice] = (try? blockGroup.reduce(initialResult: [Invoice](), { index, invoices, block in
             switch block {
             case .invoice(let invoice):
-                if let invoice = invoice.as_invoice() {
-                    return .loopReturn(invoices + [invoice])
-                }
+                return .loopReturn(invoices + [invoice.as_invoice()])
             default:
                 break
             }

damus/Core/Types/Block.swift

@@ -79,8 +79,7 @@ extension Block {
             guard let url = URL(string: block.as_str()) else { return nil }
             self = .url(url)
         case BLOCK_INVOICE:
-            guard let b = Block(invoice: block.block.invoice) else { return nil }
-            self = b
+            self = Block(invoice: block.block.invoice)
         case BLOCK_MENTION_BECH32:
             guard let b = Block(bech32: block.block.mention_bech32) else { return nil }
             self = b
@@ -113,26 +112,20 @@ fileprivate extension Block {
 }
 
 fileprivate extension Block {
-    /// Failable initializer for the C-backed type `invoice_block_t`.
-    init?(invoice: ndb_invoice_block) {
-
-        guard let invoice = invoice_block_as_invoice(invoice) else { return nil }
-        self = .invoice(invoice)
+    /// Initializer for the C-backed type `invoice_block_t`.
+    init(invoice: ndb_invoice_block) {
+        self = .invoice(invoice_block_as_invoice(invoice))
     }
 }
 
-func invoice_block_as_invoice(_ invoice: ndb_invoice_block) -> Invoice? {
+/// Converts a C-backed invoice block to a Swift Invoice.
+func invoice_block_as_invoice(_ invoice: ndb_invoice_block) -> Invoice {
     let invstr = invoice.invstr.as_str()
     let b11 = invoice.invoice
-
-    guard let description = convert_invoice_description(b11: b11) else {
-        return nil
-    }
-
+    let description = convert_invoice_description(b11: b11)
     let amount: Amount = b11.amount == 0 ? .any : .specific(Int64(b11.amount))
 
     return Invoice(description: description, amount: amount, string: invstr, expiry: b11.expiry, created_at: b11.timestamp)
-
 }
 
 fileprivate extension Block {

damus/Features/Events/Models/NoteContent.swift

@@ -191,8 +191,7 @@ func render_blocks(blocks: borrowing NdbBlockGroup, profiles: Profiles, can_hide
                 let url_type = classify_url(url)
                 urls.append(url_type)
             case .invoice(let invoice_block):
-                guard let invoice = invoice_block.as_invoice() else { break }
-                invoices.append(invoice)
+                invoices.append(invoice_block.as_invoice())
             default:
                 break
             }
@@ -258,9 +257,9 @@ func render_blocks(blocks: borrowing NdbBlockGroup, profiles: Profiles, can_hide
                 return .loopReturn(str + CompatibleText(stringLiteral: reduce_text_block(ind: index, hide_text_index: hide_text_index_argument, txt: txt.as_str())))
             case .hashtag(let htag):
                 return .loopReturn(str + hashtag_str(htag.as_str()))
-            case .invoice(let invoice):
-                guard let inv = invoice.as_invoice() else { return .loopContinue }
-                invoices.append(inv)
+            case .invoice:
+                // Invoice already added in previewable-collection switch above
+                break
             case .url(let url):
                 guard let url = URL(string: url.as_str()) else { return .loopContinue }
                 return .loopReturn(str + url_str(url))

damusTests/InvoiceTests.swift

@@ -33,10 +33,7 @@ final class InvoiceTests: XCTestCase {
             let success: Bool? = blockList.useItem(at: 0, { block in
                 switch block {
                 case .invoice(let invoiceData):
-                    guard let invoice = invoiceData.as_invoice() else {
-                        XCTFail("Cannot get invoice from invoice block")
-                        return false
-                    }
+                    let invoice = invoiceData.as_invoice()
                     XCTAssertEqual(invoice.amount, .any)
                     XCTAssertEqual(invoice.string, invstr)
                     return true
@@ -110,10 +107,7 @@ final class InvoiceTests: XCTestCase {
             let success: Bool? = blockList.useItem(at: 0, { block in
                 switch block {
                 case .invoice(let invoiceData):
-                    guard let invoice = invoiceData.as_invoice() else {
-                        XCTFail("Cannot get invoice from invoice block")
-                        return false
-                    }
+                    let invoice = invoiceData.as_invoice()
                     XCTAssertEqual(invoice.amount, .specific(10000))
                     XCTAssertEqual(invoice.expiry, 604800)
                     XCTAssertEqual(invoice.created_at, 1666139119)
@@ -174,6 +168,35 @@ final class InvoiceTests: XCTestCase {
         })
     }
 
+    /// Test parsing the specific invoice from GitHub issue that wasn't rendering
+    func testParseSpecificFailingInvoice() throws {
+        let invstr = "lnbc130n1p5h7alnpp5f83swv5wx9h25ansxsvkw7364c65vxktthy2m9ww5zf3cjrzp0vsdq9tfpygcqzysxqzjcsp5essuf0xnfeu4rpw7nllcggr6e9635xdpnaklr2fadtkwej0vvyfs9qxpqysgqddjjzxa2dwhntx8uvppx3u6pu864ul5dxkayp6jgf7n45ql5x7u9xzrvuav5rzsaz7h8d2gq455je2ezku40a5xrshu0w00ylprk03qq6kvvjd"
+
+        guard let blockGroup: NdbBlockGroup = try? NdbBlockGroup.parse(content: invstr) else {
+            XCTFail("Parsing threw an error")
+            return
+        }
+
+        blockGroup.withList({ blockList in
+            XCTAssertEqual(blockList.count, 1, "Expected 1 block, got \(blockList.count)")
+            let success: Bool? = blockList.useItem(at: 0, { block in
+                switch block {
+                case .invoice(let invoiceData):
+                    let invoice = invoiceData.as_invoice()
+                    XCTAssertEqual(invoice.amount, .specific(13000))
+                    return true
+                case .text(let txt):
+                    XCTFail("Expected invoice block, got text block")
+                    return false
+                default:
+                    XCTFail("Block is not an invoice")
+                    return false
+                }
+            })
+            XCTAssertEqual(success, true)
+        })
+    }
+
     /*
     // gh-3144: It was decided on a standup meeting that we do not need invoices to render, few people use this feature.
     func testParseInvoice() throws {

nostrdb/NdbBlock.swift

@@ -37,14 +37,11 @@ enum NdbBech32Type: UInt32 {
 }
 
 extension ndb_invoice_block {
-    func as_invoice() -> Invoice? {
+    /// Converts to a Swift Invoice object.
+    func as_invoice() -> Invoice {
         let b11 = self.invoice
         let invstr = self.invstr.as_str()
-
-        guard let description = convert_invoice_description(b11: b11) else {
-            return nil
-        }
-        
+        let description = convert_invoice_description(b11: b11)
         let amount: Amount = b11.amount == 0 ? .any : .specific(Int64(b11.amount))
 
         return Invoice(description: description, amount: amount, string: invstr, expiry: b11.expiry, created_at: b11.timestamp)
@@ -125,18 +122,18 @@ struct NdbBlockGroup: ~Copyable {
         if event.is_content_encrypted() {
             return try lendingFunction(parse(event: event, keypair: keypair))
         }
-        else if event.known_kind == .highlight {
+        if event.known_kind == .highlight {
             return try lendingFunction(parse(event: event, keypair: keypair))
         }
-        else {
         return try ndb.lookup_block_group_by_key(event: event, borrow: { group in
             switch group {
-                case .none: return try lendingFunction(parse(event: event, keypair: keypair))
-                case .some(let group): return try lendingFunction(group)
+            case .none:
+                return try lendingFunction(parse(event: event, keypair: keypair))
+            case .some(let group):
+                return try lendingFunction(group)
             }
         })
     }
-    }
     
     /// Parses the note contents on-demand from a specific note.
     ///