CR: extract method, more asserts and annotations

// FREEBIE

Signal/src/ViewControllers/OWSConversationSettingsViewController.m

@@ -171,7 +171,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert([self.thread isKindOfClass:[TSContactThread class]]);
     TSContactThread *contactThread = (TSContactThread *)self.thread;
     NSString *recipientId = contactThread.contactIdentifier;
-    return [self.contactsManager signalAccountForRecipientId:recipientId] != nil;
+    return [self.contactsManager hasSignalAccountForRecipientId:recipientId];
 }
 
 #pragma mark - ContactEditingDelegate

Signal/src/contact/OWSContactsManager.h

@@ -33,6 +33,7 @@ extern NSString *const OWSContactsManagerSignalAccountsDidChangeNotification;
 // order of the signalAccounts array respects the systems contact sorting preference
 @property (atomic, readonly) NSArray<SignalAccount *> *signalAccounts;
 - (nullable SignalAccount *)signalAccountForRecipientId:(NSString *)recipientId;
+- (BOOL)hasSignalAccountForRecipientId:(NSString *)recipientId;
 
 - (void)loadSignalAccountsFromCache;
 #pragma mark - System Contact Fetching

Signal/src/contact/OWSContactsManager.m

@@ -284,7 +284,7 @@ NSString *const OWSContactsManagerSignalAccountsDidChangeNotification
 {
     OWSAssert(recipientId.length > 0);
 
-    SignalAccount *signalAccount = [self signalAccountForRecipientId:recipientId];
+    SignalAccount *_Nullable signalAccount = [self signalAccountForRecipientId:recipientId];
     return signalAccount.displayName;
 }
 
@@ -292,7 +292,7 @@ NSString *const OWSContactsManagerSignalAccountsDidChangeNotification
 {
     OWSAssert(recipientId.length > 0);
 
-    SignalAccount *signalAccount = [self signalAccountForRecipientId:recipientId];
+    SignalAccount *_Nullable signalAccount = [self signalAccountForRecipientId:recipientId];
     return signalAccount.contact.firstName;
 }
 
@@ -300,7 +300,7 @@ NSString *const OWSContactsManagerSignalAccountsDidChangeNotification
 {
     OWSAssert(recipientId.length > 0);
 
-    SignalAccount *signalAccount = [self signalAccountForRecipientId:recipientId];
+    SignalAccount *_Nullable signalAccount = [self signalAccountForRecipientId:recipientId];
     return signalAccount.contact.lastName;
 }
 
@@ -593,6 +593,11 @@ NSString *const OWSContactsManagerSignalAccountsDidChangeNotification
     return signalAccount;
 }
 
+- (BOOL)hasSignalAccountForRecipientId:(NSString *)recipientId
+{
+    return [self signalAccountForRecipientId:recipientId] != nil;
+}
+
 - (UIImage * _Nullable)imageForPhoneIdentifier:(NSString * _Nullable)identifier {
     Contact *contact = self.allContactsMap[identifier];
     if (!contact) {

Signal/src/util/ThreadUtil.m

@@ -388,8 +388,7 @@ NS_ASSUME_NONNULL_BEGIN
                     shouldHaveAddToProfileWhitelistOffer = NO;
                 }
 
-                BOOL isContact = [contactsManager signalAccountForRecipientId:recipientId] != nil;
-                if (isContact) {
+                if ([contactsManager hasSignalAccountForRecipientId:recipientId]) {
                     // Only create "add to contacts" offers for non-contacts.
                     shouldHaveAddToContactsOffer = NO;
                     // Only create block offers for non-contacts.

SignalServiceKit/src/Contacts/SignalAccount.m

@@ -21,12 +21,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithSignalRecipient:(SignalRecipient *)signalRecipient
 {
-    if (self = [super init]) {
-        OWSAssert(signalRecipient);
-
-        _recipientId = signalRecipient.uniqueId;
-    }
-    return self;
+    OWSAssert(signalRecipient);
+    return [self initWithRecipientId:signalRecipient.recipientId];
 }
 
 - (instancetype)initWithRecipientId:(NSString *)recipientId
@@ -44,6 +40,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert([NSThread isMainThread]);
     OWSAssert(transaction);
 
+    OWSAssert(self.recipientId.length > 0);
     return [SignalRecipient recipientWithTextSecureIdentifier:self.recipientId withTransaction:transaction];
 }