Move off label and use isRepeated/isRequired. (#1765)

Continues tracking changes in protocolbuffers/protobuf#20687.

Author: thomasvl

Sources/SwiftProtobufPluginLibrary/Descriptor.swift

@@ -1089,7 +1089,9 @@ public final class FieldDescriptor {
     /// Declared type of this field.
     public private(set) var type: Google_Protobuf_FieldDescriptorProto.TypeEnum
 
-    /// optional/required/repeated
+    /// This should never be called directly. Use isRequired and isRepeated
+    /// helper methods instead.
+    // TODO(thomasvl): @available(*, deprecated, message: "Use isRequired or isRepeated instead.")
     public let label: Google_Protobuf_FieldDescriptorProto.Label
 
     /// Whether or not the field is required. For proto2 required fields and
@@ -1102,13 +1104,13 @@ public final class FieldDescriptor {
     public var isRepeated: Bool { label == .repeated }
 
     /// Use !isRequired() && !isRepeated() instead.
-    @available(*, deprecated, message: "Use !isRequired() && !isRepeated() instead.")
+    @available(*, deprecated, message: "Use !isRequired && !isRepeated instead.")
     public var isOptional: Bool { label == .optional }
 
     /// Is this field packable.
     public var isPackable: Bool {
         // This logic comes from the C++ FieldDescriptor::is_packable() impl.
-        label == .repeated && FieldDescriptor.isPackable(type: type)
+        isRepeated && FieldDescriptor.isPackable(type: type)
     }
     /// If this field is packable and packed.
     public var isPacked: Bool {
@@ -1140,7 +1142,7 @@ public final class FieldDescriptor {
     /// repeated fields, and singular proto3 fields without "optional".
     public var hasPresence: Bool {
         // This logic comes from the C++ FieldDescriptor::has_presence() impl.
-        guard label != .repeated else { return false }
+        guard !isRepeated else { return false }
         switch type {
         case .group, .message:
             // Groups/messages always get field presence.

Sources/protoc-gen-swift/Descriptor+Extensions.swift

@@ -332,26 +332,24 @@ extension FieldDescriptor {
         case .sint64: result = "Int64"
         }
 
-        if label == .repeated {
+        if isRepeated {
             return "[\(result)]"
         }
         return result
     }
 
     func swiftStorageType(namer: SwiftProtobufNamer) -> String {
         let swiftType = self.swiftType(namer: namer)
-        switch label {
-        case .repeated:
+        if isRepeated {
+            return swiftType
+        }
+        guard realContainingOneof == nil else {
+            return swiftType
+        }
+        if hasPresence {
+            return "\(swiftType)?"
+        } else {
             return swiftType
-        case .optional, .required:
-            guard realContainingOneof == nil else {
-                return swiftType
-            }
-            if hasPresence {
-                return "\(swiftType)?"
-            } else {
-                return swiftType
-            }
         }
     }
 
@@ -384,7 +382,7 @@ extension FieldDescriptor {
         if isMap {
             return "[:]"
         }
-        if label == .repeated {
+        if isRepeated {
             return "[]"
         }
 

Sources/protoc-gen-swift/ExtensionSetGenerator.swift

@@ -33,10 +33,12 @@ class ExtensionSetGenerator {
 
         var extensionFieldType: String {
             let label: String
-            switch fieldDescriptor.label {
-            case .optional: label = "Optional"
-            case .required: label = "Required"
-            case .repeated: label = fieldDescriptor.isPacked ? "Packed" : "Repeated"
+            if fieldDescriptor.isRequired {
+                label = "Required"
+            } else if fieldDescriptor.isRepeated {
+                label = fieldDescriptor.isPacked ? "Packed" : "Repeated"
+            } else {
+                label = "Optional"
             }
 
             let modifier: String
@@ -69,7 +71,8 @@ class ExtensionSetGenerator {
 
             var fieldNamePath: String
             if fieldDescriptor.containingType.useMessageSetWireFormat && fieldDescriptor.type == .message
-                && fieldDescriptor.label == .optional && fieldDescriptor.messageType === fieldDescriptor.extensionScope
+                && (!fieldDescriptor.isRepeated && !fieldDescriptor.isRequired)
+                && fieldDescriptor.messageType === fieldDescriptor.extensionScope
             {
                 fieldNamePath = fieldDescriptor.messageType!.fullName
             } else {
@@ -105,7 +108,8 @@ class ExtensionSetGenerator {
             p.print("}")
 
             // Repeated extension fields can use .isEmpty and clear by setting to the empty list.
-            if fieldDescriptor.label != .repeated {
+            // Everything else gets a "has" helper.
+            if !fieldDescriptor.isRepeated {
                 p.print(
                     "/// Returns true if extension `\(swiftFullExtensionName)`\n/// has been explicitly set.",
                     "\(visibility)var \(extensionNames.has): Bool {"