Handle npub correctly in draft notes

Damus stores npub as both Strings and URLs in NSAttributedString.Key.link when a note is saved as a draft. Make Damus correctly handle both when we retrieve and store drafts.

Changelog-Changed: Handle npub correctly in draft notes
Signed-off-by: Askeew <askeew@hotmail.com>
Closes: https://github.com/damus-io/damus/issues/2923

damus/Views/PostView.swift

@@ -863,7 +863,9 @@ func build_post(state: DamusState, post: NSAttributedString, action: PostAction,
 func build_post(state: DamusState, post: NSAttributedString, action: PostAction, uploadedMedias: [UploadedMedia], pubkeys: [Pubkey]) -> NostrPost {
     let post = NSMutableAttributedString(attributedString: post)
     post.enumerateAttributes(in: NSRange(location: 0, length: post.length), options: []) { attributes, range, stop in
-        if let link = attributes[.link] as? String {
+        let linkValue = attributes[.link]
+        let link = (linkValue as? String) ?? (linkValue as? URL)?.absoluteString
+        if let link {
             let nextCharIndex = range.upperBound
             if nextCharIndex < post.length,
                let nextChar = post.attributedSubstring(from: NSRange(location: nextCharIndex, length: 1)).string.first,

damusTests/PostViewTests.swift

@@ -176,6 +176,48 @@ final class PostViewTests: XCTestCase {
 
         XCTAssertEqual(post.tags, [["q", test_note.id.hex()]])
     }
+
+    func testBuildPostRecognizesStringsAsNpubs() throws {
+        // given
+        let expectedLink = "nostr:\(test_pubkey.npub)"
+        let content = NSMutableAttributedString(string: "@test", attributes: [
+            NSAttributedString.Key.link: "damus:\(expectedLink)"
+        ])
+
+        // when
+        let post = build_post(
+            state: test_damus_state,
+            post: content,
+            action: .posting(.user(test_pubkey)),
+            uploadedMedias: [],
+            pubkeys: []
+        )
+
+        // then
+        XCTAssertEqual(post.content, expectedLink)
+    }
+
+    func testBuildPostRecognizesUrlsAsNpubs() throws {
+        // given
+        guard let npubUrl = URL(string: "damus:nostr:\(test_pubkey.npub)") else {
+            return XCTFail("Could not create URL")
+        }
+        let content = NSMutableAttributedString(string: "@test", attributes: [
+            NSAttributedString.Key.link: npubUrl
+        ])
+
+        // when
+        let post = build_post(
+            state: test_damus_state,
+            post: content,
+            action: .posting(.user(test_pubkey)),
+            uploadedMedias: [],
+            pubkeys: []
+        )
+
+        // then
+        XCTAssertEqual(post.content, "nostr:\(test_pubkey.npub)")
+    }
 }
 
 func checkMentionLinkEditorHandling(