Respond to Cr.

SignalServiceKit/src/Messages/DeviceSyncing/OWSIncomingSentMessageTranscript.m

@@ -45,8 +45,15 @@ NS_ASSUME_NONNULL_BEGIN
 
     _quotedMessage = [TSQuotedMessage quotedMessageForDataMessage:_dataMessage thread:_thread transaction:transaction];
     _contact = [OWSContacts contactForDataMessage:_dataMessage transaction:transaction];
-    _linkPreview =
-        [OWSLinkPreview buildValidatedLinkPreviewWithDataMessage:_dataMessage body:_body transaction:transaction];
+
+    NSError *linkPreviewError;
+    _linkPreview = [OWSLinkPreview buildValidatedLinkPreviewWithDataMessage:_dataMessage
+                                                                       body:_body
+                                                                transaction:transaction
+                                                                      error:&linkPreviewError];
+    if (linkPreviewError && ![OWSLinkPreview isNoPreviewError:linkPreviewError]) {
+        OWSLogError(@"linkPreviewError: %@", linkPreviewError);
+    }
 
     if (sentProto.unidentifiedStatus.count > 0) {
         NSMutableArray<NSString *> *nonUdRecipientIds = [NSMutableArray new];

SignalServiceKit/src/Messages/Interactions/OWSLinkPreview.swift

@@ -4,6 +4,13 @@
 
 import Foundation
 
+@objc
+public enum LinkPreviewError: Int, Error {
+    case invalidInput
+    case assertionFailure
+    case noPreview
+}
+
 @objc(OWSLinkPreview)
 public class OWSLinkPreview: MTLModel {
     @objc
@@ -13,13 +20,13 @@ public class OWSLinkPreview: MTLModel {
     public var title: String?
 
     @objc
-    public var attachmentId: String?
+    public var imageAttachmentId: String?
 
     @objc
-    public init(urlString: String, title: String?, attachmentId: String?) {
+    public init(urlString: String, title: String?, imageAttachmentId: String?) {
         self.urlString = urlString
         self.title = title
-        self.attachmentId = attachmentId
+        self.imageAttachmentId = imageAttachmentId
 
         super.init()
     }
@@ -34,28 +41,36 @@ public class OWSLinkPreview: MTLModel {
         try super.init(dictionary: dictionaryValue)
     }
 
+    @objc
+    public class func isNoPreviewError(_ error: Error) -> Bool {
+        guard let error = error as? LinkPreviewError else {
+            return false
+        }
+        return error == .noPreview
+    }
+
     @objc
     public class func buildValidatedLinkPreview(dataMessage: SSKProtoDataMessage,
                                                 body: String?,
-                                                transaction: YapDatabaseReadWriteTransaction) -> OWSLinkPreview? {
+                                                transaction: YapDatabaseReadWriteTransaction) throws -> OWSLinkPreview {
         guard let previewProto = dataMessage.preview else {
-            return nil
+            throw LinkPreviewError.noPreview
         }
         let urlString = previewProto.url
 
         guard URL(string: urlString) != nil else {
-            owsFailDebug("Could not parse preview URL.")
-            return nil
+            Logger.error("Could not parse preview URL.")
+            throw LinkPreviewError.invalidInput
         }
 
         guard let body = body else {
-            owsFailDebug("Preview for message without body.")
-            return nil
+            Logger.error("Preview for message without body.")
+            throw LinkPreviewError.invalidInput
         }
         let bodyComponents = body.components(separatedBy: .whitespacesAndNewlines)
         guard bodyComponents.contains(urlString) else {
-            owsFailDebug("URL not present in body.")
-            return nil
+            Logger.error("URL not present in body.")
+            throw LinkPreviewError.invalidInput
         }
 
         // TODO: Verify that url host is in whitelist.
@@ -68,7 +83,8 @@ public class OWSLinkPreview: MTLModel {
                 imageAttachmentPointer.save(with: transaction)
                 imageAttachmentId = imageAttachmentPointer.uniqueId
             } else {
-                owsFailDebug("Could not parse image proto.")
+                Logger.error("Could not parse image proto.")
+                throw LinkPreviewError.invalidInput
             }
         }
 
@@ -78,20 +94,20 @@ public class OWSLinkPreview: MTLModel {
         }
         let hasImage = imageAttachmentId != nil
         if !hasTitle && !hasImage {
-            owsFailDebug("Preview has neither title nor image.")
-            return nil
+            Logger.error("Preview has neither title nor image.")
+            throw LinkPreviewError.invalidInput
         }
 
-        return OWSLinkPreview(urlString: urlString, title: title, attachmentId: imageAttachmentId)
+        return OWSLinkPreview(urlString: urlString, title: title, imageAttachmentId: imageAttachmentId)
     }
 
     @objc
     public func removeAttachment(transaction: YapDatabaseReadWriteTransaction) {
-        guard let attachmentId = attachmentId else {
+        guard let imageAttachmentId = imageAttachmentId else {
             owsFailDebug("No attachment id.")
             return
         }
-        guard let attachment = TSAttachment.fetch(uniqueId: attachmentId, transaction: transaction) else {
+        guard let attachment = TSAttachment.fetch(uniqueId: imageAttachmentId, transaction: transaction) else {
             owsFailDebug("Could not load attachment.")
             return
         }

SignalServiceKit/src/Messages/Interactions/TSMessage.m

@@ -351,7 +351,7 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
         [self.contactShare removeAvatarAttachmentWithTransaction:transaction];
     }
 
-    if (self.linkPreview.attachmentId) {
+    if (self.linkPreview.imageAttachmentId) {
         [self.linkPreview removeAttachmentWithTransaction:transaction];
     }
 

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1287,10 +1287,15 @@ NS_ASSUME_NONNULL_BEGIN
                                                                                                  thread:oldGroupThread
                                                                                             transaction:transaction];
 
+                NSError *linkPreviewError;
                 OWSLinkPreview *_Nullable linkPreview =
                     [OWSLinkPreview buildValidatedLinkPreviewWithDataMessage:dataMessage
                                                                         body:body
-                                                                 transaction:transaction];
+                                                                 transaction:transaction
+                                                                       error:&linkPreviewError];
+                if (linkPreviewError && ![OWSLinkPreview isNoPreviewError:linkPreviewError]) {
+                    OWSLogError(@"linkPreviewError: %@", linkPreviewError);
+                }
 
                 OWSLogDebug(@"incoming message from: %@ for group: %@ with timestamp: %lu",
                     envelopeAddress(envelope),
@@ -1355,8 +1360,15 @@ NS_ASSUME_NONNULL_BEGIN
                                                                                          thread:thread
                                                                                     transaction:transaction];
 
+        NSError *linkPreviewError;
         OWSLinkPreview *_Nullable linkPreview =
-            [OWSLinkPreview buildValidatedLinkPreviewWithDataMessage:dataMessage body:body transaction:transaction];
+            [OWSLinkPreview buildValidatedLinkPreviewWithDataMessage:dataMessage
+                                                                body:body
+                                                         transaction:transaction
+                                                               error:&linkPreviewError];
+        if (linkPreviewError && ![OWSLinkPreview isNoPreviewError:linkPreviewError]) {
+            OWSLogError(@"linkPreviewError: %@", linkPreviewError);
+        }
 
         // Legit usage of senderTimestamp when creating incoming message from received envelope
         TSIncomingMessage *incomingMessage =

SignalServiceKit/tests/Messages/OWSLinkPreviewTest.swift

@@ -18,6 +18,77 @@ class OWSLinkPreviewTest: SSKBaseTestSwift {
         super.tearDown()
     }
 
+    func testBuildValidatedLinkPreview_TitleAndImage() {
+        let url = "https://www.youtube.com/watch?v=tP-Ipsat90c"
+        let body = "\(url)"
+        let previewBuilder = SSKProtoDataMessagePreview.builder(url: url)
+        previewBuilder.setTitle("Some Youtube Video")
+        let imageAttachmentBuilder = SSKProtoAttachmentPointer.builder(id: 1)
+        imageAttachmentBuilder.setKey(Randomness.generateRandomBytes(32))
+        imageAttachmentBuilder.setContentType(OWSMimeTypeImageJpeg)
+        previewBuilder.setImage(try! imageAttachmentBuilder.build())
+        let dataBuilder = SSKProtoDataMessage.builder()
+        dataBuilder.setPreview(try! previewBuilder.build())
+
+        self.readWrite { (transaction) in
+            XCTAssertNotNil(try! OWSLinkPreview.buildValidatedLinkPreview(dataMessage: try! dataBuilder.build(),
+                                                                     body: body,
+                                                                     transaction: transaction))
+        }
+    }
+
+    func testBuildValidatedLinkPreview_Title() {
+        let url = "https://www.youtube.com/watch?v=tP-Ipsat90c"
+        let body = "\(url)"
+        let previewBuilder = SSKProtoDataMessagePreview.builder(url: url)
+        previewBuilder.setTitle("Some Youtube Video")
+        let dataBuilder = SSKProtoDataMessage.builder()
+        dataBuilder.setPreview(try! previewBuilder.build())
+
+        self.readWrite { (transaction) in
+            XCTAssertNotNil(try! OWSLinkPreview.buildValidatedLinkPreview(dataMessage: try! dataBuilder.build(),
+                                                                     body: body,
+                                                                     transaction: transaction))
+        }
+    }
+
+    func testBuildValidatedLinkPreview_Image() {
+        let url = "https://www.youtube.com/watch?v=tP-Ipsat90c"
+        let body = "\(url)"
+        let previewBuilder = SSKProtoDataMessagePreview.builder(url: url)
+        let imageAttachmentBuilder = SSKProtoAttachmentPointer.builder(id: 1)
+        imageAttachmentBuilder.setKey(Randomness.generateRandomBytes(32))
+        imageAttachmentBuilder.setContentType(OWSMimeTypeImageJpeg)
+        previewBuilder.setImage(try! imageAttachmentBuilder.build())
+        let dataBuilder = SSKProtoDataMessage.builder()
+        dataBuilder.setPreview(try! previewBuilder.build())
+
+        self.readWrite { (transaction) in
+            XCTAssertNotNil(try! OWSLinkPreview.buildValidatedLinkPreview(dataMessage: try! dataBuilder.build(),
+                                                                     body: body,
+                                                                     transaction: transaction))
+        }
+    }
+
+    func testBuildValidatedLinkPreview_NoTitleOrImage() {
+        let url = "https://www.youtube.com/watch?v=tP-Ipsat90c"
+        let body = "\(url)"
+        let previewBuilder = SSKProtoDataMessagePreview.builder(url: url)
+        let dataBuilder = SSKProtoDataMessage.builder()
+        dataBuilder.setPreview(try! previewBuilder.build())
+
+        self.readWrite { (transaction) in
+            do {
+                _ = try OWSLinkPreview.buildValidatedLinkPreview(dataMessage: try! dataBuilder.build(),
+                                                         body: body,
+                                                         transaction: transaction)
+                XCTFail("Missing expected error.")
+            } catch {
+                // Do nothing.
+            }
+        }
+    }
+
     func testIsValidLinkUrl() {
         XCTAssertTrue(OWSLinkPreview.isValidLinkUrl("https://www.youtube.com/watch?v=tP-Ipsat90c"))
         XCTAssertTrue(OWSLinkPreview.isValidLinkUrl("https://youtube.com/watch?v=tP-Ipsat90c"))