Sidestep `SourceKitten`'s off-by-one bug when parsing generic parameter inheritance.

Generator/Source/CuckooGeneratorFramework/Tokenizer.swift

@@ -99,6 +99,9 @@ public struct Tokenizer {
             let children = subtokens.noneOf(Initializer.self)
             let genericParameters = subtokens.only(GenericParameter.self)
 
+            // FIXME: Remove when SourceKitten fixes the off-by-one error that includes the ending `>` in the last inherited type.
+            let fixedGenericParameters = fixSourceKittenLastGenericParameterBug(genericParameters)
+
             return ProtocolDeclaration(
                 name: name,
                 accessibility: accessibility,
@@ -109,7 +112,7 @@ public struct Tokenizer {
                 children: children,
                 inheritedTypes: tokenizedInheritedTypes,
                 attributes: attributes,
-                genericParameters: genericParameters)
+                genericParameters: fixedGenericParameters)
 
         case Kinds.ClassDeclaration.rawValue:
             let subtokens = tokenize(dictionary[Key.Substructure.rawValue] as? [SourceKitRepresentable] ?? [])
@@ -124,6 +127,9 @@ public struct Tokenizer {
             }
             let genericParameters = subtokens.only(GenericParameter.self)
 
+            // FIXME: Remove when SourceKitten fixes the off-by-one error that includes the ending `>` in the last inherited type.
+            let fixedGenericParameters = fixSourceKittenLastGenericParameterBug(genericParameters)
+
             return ClassDeclaration(
                 name: name,
                 accessibility: accessibility,
@@ -134,7 +140,7 @@ public struct Tokenizer {
                 children: children,
                 inheritedTypes: tokenizedInheritedTypes,
                 attributes: attributes,
-                genericParameters: genericParameters)
+                genericParameters: fixedGenericParameters)
 
         case Kinds.ExtensionDeclaration.rawValue:
             return ExtensionDeclaration(range: range!)
@@ -185,6 +191,9 @@ public struct Tokenizer {
                 }
             }
 
+            // FIXME: Remove when SourceKitten fixes the off-by-one error that includes the ending `>` in the last inherited type.
+            let fixedGenericParameters = fixSourceKittenLastGenericParameterBug(genericParameters)
+
             // When bodyRange != nil, we need to create `ClassMethod` instead of `ProtocolMethod`
             if let bodyRange = bodyRange {
                 return ClassMethod(
@@ -196,7 +205,7 @@ public struct Tokenizer {
                     parameters: namedParameters,
                     bodyRange: bodyRange,
                     attributes: attributes,
-                    genericParameters: genericParameters)
+                    genericParameters: fixedGenericParameters)
             } else {
                 return ProtocolMethod(
                     name: name,
@@ -206,7 +215,7 @@ public struct Tokenizer {
                     nameRange: nameRange!,
                     parameters: namedParameters,
                     attributes: attributes,
-                    genericParameters: genericParameters)
+                    genericParameters: fixedGenericParameters)
             }
 
         case Kinds.GenericParameter.rawValue:
@@ -292,6 +301,7 @@ public struct Tokenizer {
             let inheritedTypeElement = (dictionary[Key.InheritedTypes.rawValue] as? [SourceKitRepresentable] ?? []).first
             let inheritedType = (inheritedTypeElement as? [String: SourceKitRepresentable] ?? [:])[Key.Name.rawValue] as? String
             let inheritanceDeclaration: InheritanceDeclaration?
+
             if let inheritedType = inheritedType {
                 inheritanceDeclaration = .init(name: inheritedType)
             } else {
@@ -468,6 +478,26 @@ public struct Tokenizer {
 
         return ReturnSignature(throwString: throwString, returnType: returnType ?? WrappableType.type("Void"), whereConstraints: whereConstraints)
     }
+
+    // FIXME: Remove when SourceKitten fixes the off-by-one error that includes the ending `>` in the last inherited type.
+    private func fixSourceKittenLastGenericParameterBug(_ genericParameters: [GenericParameter]) -> [GenericParameter] {
+        let fixedGenericParameters: [GenericParameter]
+        if let lastGenericParameter = genericParameters.last,
+            let inheritedType = lastGenericParameter.inheritedType,
+            inheritedType.name.hasSuffix(">>") == true {
+            fixedGenericParameters = genericParameters.dropLast() + [
+                GenericParameter(
+                    name: lastGenericParameter.name,
+                    range: lastGenericParameter.range.lowerBound..<lastGenericParameter.range.upperBound - 1,
+                    inheritedType: InheritanceDeclaration(name: String(inheritedType.name.dropLast()))
+                )
+            ]
+        } else {
+            fixedGenericParameters = genericParameters
+        }
+
+        return fixedGenericParameters
+    }
 }
 
 extension String {

Tests/Swift/Source/GenericClass.swift

@@ -22,6 +22,10 @@ class GenericClass<T: CustomStringConvertible, U: Codable & CustomStringConverti
         readWritePropertyV = theV
     }
 
+    func genericMethodParameter<G: GenericClass<T, U, V>>(g: G) {}
+
+    func genericMethodParameterNested<G: GenericClass<T, [Int], Array<String>>>(g: G) {}
+
     func genericWhereMethodParameter<G>(g: G) where G: GenericClass<T, [Int], V> {}
 
     func genericWhereMethodParameterNested<G>(g: G) where G: GenericClass<T, U, Array<String>> {}