From 47bfc3ec98fb81d261f7def6637c977756886e91 Mon Sep 17 00:00:00 2001
From: Tien Nguyen <viettien23102006@gmail.com>
Date: Tue, 16 Jun 2026 06:47:27 -0400
Subject: [PATCH] fail eagerly when missing JavaObject mapping

---
 .../JavaClassTranslator.swift                 |  4 ++
 .../Java2SwiftTests.swift                     | 39 ++++++++++++++-----
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/Sources/SwiftJavaToolLib/JavaClassTranslator.swift b/Sources/SwiftJavaToolLib/JavaClassTranslator.swift
index 37e631a91..ded0f80e8 100644
--- a/Sources/SwiftJavaToolLib/JavaClassTranslator.swift
+++ b/Sources/SwiftJavaToolLib/JavaClassTranslator.swift
@@ -137,6 +137,10 @@ struct JavaClassTranslator {
     // Superclass, incl parameter types (if any)
     if !javaClass.isInterface() {
       var javaSuperclass = javaClass.getSuperclass()
+      if javaSuperclass != nil, translator.translatedClasses[JavaObject.fullJavaClassName] == nil {
+        throw TranslationError.untranslatedJavaClass(JavaObject.fullJavaClassName)
+      }
+
       var javaGenericSuperclass: Type? = javaClass.getGenericSuperclass()
       var swiftSuperclassName: String? = nil
       var swiftSuperclassTypeArgs: [String]? = nil
diff --git a/Tests/SwiftJavaToolLibTests/Java2SwiftTests.swift b/Tests/SwiftJavaToolLibTests/Java2SwiftTests.swift
index b9a279022..374d2b332 100644
--- a/Tests/SwiftJavaToolLibTests/Java2SwiftTests.swift
+++ b/Tests/SwiftJavaToolLibTests/Java2SwiftTests.swift
@@ -175,7 +175,7 @@ class Java2SwiftTests: XCTestCase {
         """,
         """
         extension ProcessBuilder {
-          @JavaClass("java.lang.ProcessBuilder$Redirect")
+          @JavaClass("java.lang.ProcessBuilder$Redirect", extends: JavaObject.self)
           public struct Redirect {
         """,
         """
@@ -183,7 +183,7 @@ class Java2SwiftTests: XCTestCase {
         """,
         """
         extension ProcessBuilder.Redirect {
-          @JavaClass("java.lang.ProcessBuilder$Redirect$Type")
+          @JavaClass("java.lang.ProcessBuilder$Redirect$Type", extends: JavaObject.self)
           public struct Type {
         """,
         """
@@ -220,7 +220,7 @@ class Java2SwiftTests: XCTestCase {
         """,
         """
         extension ProcessBuilder {
-          @JavaClass("java.lang.ProcessBuilder$Redirect")
+          @JavaClass("java.lang.ProcessBuilder$Redirect", extends: JavaObject.self)
           public struct PBRedirect {
         """,
         """
@@ -228,7 +228,7 @@ class Java2SwiftTests: XCTestCase {
         """,
         """
         extension ProcessBuilder.PBRedirect {
-          @JavaClass("java.lang.ProcessBuilder$Redirect$Type")
+          @JavaClass("java.lang.ProcessBuilder$Redirect$Type", extends: JavaObject.self)
           public struct JavaType {
         """,
         """
@@ -245,7 +245,7 @@ class Java2SwiftTests: XCTestCase {
       swiftTypeName: "JavaString",
       expectedChunks: [
         """
-        @JavaClass("java.lang.String")
+        @JavaClass("java.lang.String", extends: JavaObject.self)
         public struct JavaString {
         """
       ]
@@ -313,9 +313,6 @@ class Java2SwiftTests: XCTestCase {
       JavaString.self,
       swiftTypeName: "JavaString",
       asClass: true,
-      translatedClasses: [
-        "java.lang.Object": SwiftTypeName(module: "SwiftJava", name: "JavaObject")
-      ],
       expectedChunks: [
         "import SwiftJava",
         """
@@ -346,6 +343,30 @@ class Java2SwiftTests: XCTestCase {
     )
   }
 
+  func testMissingJavaObjectMappingFailsEagerly() throws {
+    let environment = try jvm.environment()
+    let translator = JavaTranslator(
+      config: Configuration(),
+      swiftModuleName: "SwiftModule",
+      environment: environment,
+      translateAsClass: true
+    )
+    translator.translatedClasses = [:]
+    translator.translatedClasses[JavaString.fullJavaClassName] = SwiftTypeName(module: nil, name: "JavaString")
+    translator.startNewFile()
+
+    try JavaString.withJNIClass(in: environment) { javaClass in
+      XCTAssertThrowsError(
+        try translator.translateClass(JavaClass<JavaObject>(javaThis: javaClass, environment: environment))
+      ) { error in
+        XCTAssertEqual(
+          String(describing: error),
+          "Java class 'java.lang.Object' has not been translated into Swift"
+        )
+      }
+    }
+  }
+
   func testEnumAsClass() throws {
     try assertTranslatedClass(
       JavaMonth.self,
@@ -726,7 +747,7 @@ func assertTranslatedClass<JavaClassType: AnyJavaObject>(
     translateAsClass: asClass
   )
 
-  translator.translatedClasses = translatedClasses
+  translator.translatedClasses.merge(translatedClasses) { _, new in new }
   translator.translatedClasses[javaType.fullJavaClassName] = SwiftTypeName(module: nil, name: swiftTypeName)
   translator.nestedClasses = nestedClasses
   translator.startNewFile()