Java2Swift: Small fixes in support of nested classes

Author: DougGregor

Sources/Java2SwiftLib/JavaTranslator.swift

@@ -193,6 +193,7 @@ extension JavaTranslator {
   package func translateClass(_ javaClass: JavaClass<JavaObject>) -> [DeclSyntax] {
     let fullName = javaClass.getName()
     let swiftTypeName = try! getSwiftTypeNameFromJavaClassName(fullName)
+    let (swiftParentType, swiftInnermostTypeName) = swiftTypeName.splitSwiftTypeName()
 
     // Superclass.
     let extends: String
@@ -265,7 +266,7 @@ extension JavaTranslator {
     )
 
     if !enumConstants.isEmpty {
-      let enumName = "\(swiftTypeName)Cases"
+      let enumName = "\(swiftInnermostTypeName)Cases"
       members.append(
         contentsOf: translateToEnumValue(name: enumName, enumFields: enumConstants)
       )
@@ -357,7 +358,6 @@ extension JavaTranslator {
     }
 
     // Emit the struct declaration describing the java class.
-    let (swiftParentType, swiftInnermostTypeName) = swiftTypeName.splitSwiftTypeName()
     let classOrInterface: String = javaClass.isInterface() ? "JavaInterface" : "JavaClass";
     var classDecl =
       """

Tests/Java2SwiftTests/Java2SwiftTests.swift

@@ -136,6 +136,51 @@ class Java2SwiftTests: XCTestCase {
       ]
     )
   }
+
+  func testNestedLogger() throws {
+    try assertTranslatedClass(
+      JavaSystem.Logger.self,
+      swiftTypeName: "JavaSystem.Logger",
+      translatedClasses: [
+        "java.lang.Object": ("JavaObject", nil, true),
+        "java.lang.System": ("JavaSystem", nil, true)
+      ],
+      expectedChunks: [
+        """
+        extension JavaSystem {
+          @JavaInterface("java.lang.System$Logger")
+          public struct Logger {
+        """
+      ]
+    )
+  }
+
+  func testNestedLoggerLevel() throws {
+    try assertTranslatedClass(
+      JavaSystem.Logger.Level.self,
+      swiftTypeName: "JavaSystem.Logger.Level",
+      translatedClasses: [
+        "java.lang.Object": ("JavaObject", nil, true),
+        "java.lang.System": ("JavaSystem", nil, true),
+        "java.lang.System.Logger": ("JavaSystem.Logger", nil, true),
+      ],
+      expectedChunks: [
+        """
+        extension JavaSystem.Logger {
+          @JavaClass("java.lang.System$Logger$Level")
+          public struct Level {
+        """,
+        """
+            public enum LevelCases: Equatable {
+        """,
+        """
+        extension JavaClass<JavaSystem.Logger.Level> {
+          @JavaStaticField
+          public var ALL: JavaSystem.Logger.Level?
+        """,
+      ]
+    )
+  }
 }
 
 @JavaClass("java.util.ArrayList")
@@ -146,6 +191,22 @@ public struct MyArrayList<E: AnyJavaObject> {
 public struct MyLinkedList<E: AnyJavaObject> {
 }
 
+@JavaClass("java.lang.System")
+public struct JavaSystem {
+}
+
+extension JavaSystem {
+  @JavaClass("java.lang.System$Logger")
+  public struct Logger {
+  }
+}
+
+extension JavaSystem.Logger {
+  @JavaClass("java.lang.System$Logger$Level")
+  public struct Level {
+  }
+}
+
 /// Translate a Java class and assert that the translated output contains
 /// each of the expected "chunks" of text.
 func assertTranslatedClass<JavaClassType: AnyJavaObject>(