Java2Swift: Correctly determine if a Swift method will be an override.

When looking for a declared method with a given signature, we need to
check all superclasses that have been mapped into Swift, not just the
closest one.

Author: DougGregor

Sources/Java2SwiftLib/JavaClassTranslator.swift

@@ -664,15 +664,30 @@ extension JavaClassTranslator {
   /// Determine whether this method is an override of another Java
   /// method.
   func isOverride(_ method: Method) -> Bool {
-    guard let javaSuperclass = effectiveJavaSuperclass else {
-      return false
-    }
+    var currentSuperclass = effectiveJavaSuperclass
+    while let currentSuperclassNonOpt = currentSuperclass {
+      // Set the loop up for the next run.
+      defer {
+        currentSuperclass = currentSuperclassNonOpt.getSuperclass()
+      }
+
+      do {
+        // If this class didn't get translated into Swift, skip it.
+        if translator.translatedClasses[currentSuperclassNonOpt.getName()] == nil {
+          continue
+        }
 
-    do {
-      let overriddenMethod = try javaSuperclass.getDeclaredMethod(method.getName(), method.getParameterTypes())
-      return overriddenMethod != nil
-    } catch {
-      return false
+        // If this superclass declares a method with the same parameter types,
+        // we have an override.
+        let overriddenMethod = try currentSuperclassNonOpt
+          .getDeclaredMethod(method.getName(), method.getParameterTypes())
+        if overriddenMethod != nil {
+          return true
+        }
+      } catch {
+      }
     }
+
+    return false
   }
 }

Tests/Java2SwiftTests/Java2SwiftTests.swift

@@ -422,6 +422,32 @@ class Java2SwiftTests: XCTestCase {
       ]
     )
   }
+
+  func testOverrideSkipImmediateSuperclass() throws {
+    // JavaByte overrides equals() from JavaObject, which it indirectly
+    // inherits through JavaNumber
+    try assertTranslatedClass(
+      JavaByte.self,
+      swiftTypeName: "JavaByte",
+      asClass: true,
+      translatedClasses: [
+        "java.lang.Object" : ("JavaObject", "JavaKit"),
+        "java.lang.Number" : ("JavaNumber", "JavaKit"),
+        "java.lang.Byte" : ("JavaByte", "JavaKit"),
+      ],
+      expectedChunks: [
+        "import JavaKit",
+        """
+        @JavaClass("java.lang.Byte")
+        open class JavaByte: JavaNumber {
+        """,
+        """
+          @JavaMethod
+          open override func equals(_ arg0: JavaObject?) -> Bool
+        """,
+      ]
+    )
+  }
 }
 
 @JavaClass("java.lang.ClassLoader")