[J2KT] Change readable/java/protobuf to use untranspiled Java classes…

… for fake protos/fake proto runtime.

Use j2kt_native_import for fake protos/fake proto runtime on J2kt native (matching real protos).

This means we test that message field access (which j2kt rewrites from getter to property read) works with both Kotlin/Native protos (which has only properties) and JavaLite/J2cl protos (which have only getters used via Kotlin/Java interop).

PiperOrigin-RevId: 716621985

transpiler/javatests/com/google/j2cl/readable/java/protobuf/BUILD

@@ -1,4 +1,6 @@
-load("//build_defs:rules.bzl", "j2kt_jvm_library", "j2kt_native_library")
+load("@bazel_tools//tools/build_defs/kotlin/native:rules.bzl", "kt_native_library")
+load("//build_defs:rules.bzl", "j2cl_library", "j2kt_native_import")
+load("@rules_java//java:defs.bzl", "java_library")
 load(
     "//transpiler/javatests/com/google/j2cl/readable:readable_example.bzl",
     "readable_example",
@@ -9,34 +11,61 @@ package(
     licenses = ["notice"],
 )
 
-j2kt_jvm_library(
-    name = "readable-j2kt-jvm",
-    srcs = glob([
-        "*.java",
-        "*.kt",
-    ]),
+# The source files that we want to test. Other files are part of the test fixture.
+READABLE_SRCS = [
+    "Protobuf.java",
+]
+
+java_library(
+    name = "testfixture",
+    srcs = glob(
+        ["*.java"],
+        exclude = READABLE_SRCS,
+    ),
     deps = [
-        "//jre/java:javaemul_internal_annotations-j2kt-jvm",
-        "//third_party:jspecify_annotations-j2kt-jvm",
+        "//third_party:jspecify_annotations",
     ],
 )
 
-j2kt_native_library(
-    name = "readable-j2kt-native",
-    srcs = glob([
-        "*.java",
-        "*.kt",
-    ]),
+# J2kt-JVM proto dependencies are untranspiled Java libraries
+alias(
+    name = "testfixture-j2kt-jvm",
+    actual = "testfixture",
+)
+
+kt_native_library(
+    name = "testfixture-kt-native",
+    srcs = glob(["*.kt"]),
+    tags = ["manual"],
+)
+
+# Kotlin Native proto dependencies are imported Kotlin Native libraries
+j2kt_native_import(
+    name = "testfixture-j2kt-native",
+    jar = "testfixture",
+    runtime = "testfixture-kt-native",
+    tags = ["manual"],
+)
+
+# Other transpiled platforms that do not involve Kotlin
+j2cl_library(
+    name = "testfixture-j2cl",
+    srcs = glob(
+        ["*.java"],
+        exclude = READABLE_SRCS,
+    ),
+    experimental_enable_jspecify_support_do_not_enable_without_jspecify_static_checking_or_you_might_cause_an_outage = True,
     deps = [
-        "//jre/java:javaemul_internal_annotations-j2kt-native",
-        "//third_party:jspecify_annotations-j2kt-native",
+        "//jre/java:javaemul_internal_annotations-j2cl",
+        "//third_party:jspecify_annotations-j2cl",
     ],
 )
 
 readable_example(
-    srcs = glob(["*.java"]),
+    srcs = READABLE_SRCS,
     experimental_enable_jspecify_support_do_not_enable_without_jspecify_static_checking_or_you_might_cause_an_outage = True,
     deps = [
+        ":testfixture-j2cl",
         "//jre/java:javaemul_internal_annotations-j2cl",
         "//third_party:jspecify_annotations-j2cl",
     ],

transpiler/javatests/com/google/j2cl/readable/java/protobuf/EnumLite.java

@@ -15,9 +15,6 @@
  */
 package com.google.protobuf;
 
-import javaemul.internal.annotations.KtNative;
-
-@KtNative
 public interface EnumLite {
   int getNumber();
 }

transpiler/javatests/com/google/j2cl/readable/java/protobuf/GeneratedMessage.java

@@ -15,10 +15,8 @@
  */
 package com.google.protobuf;
 
-import javaemul.internal.annotations.KtNative;
 import org.jspecify.annotations.NullMarked;
 
-@KtNative
 @NullMarked
 public class GeneratedMessage {
   // Emulates Kotlin property

transpiler/javatests/com/google/j2cl/readable/java/protobuf/MyEnum.java

@@ -17,14 +17,13 @@
 
 import com.google.protobuf.EnumLite;
 import com.google.protobuf.Internal.ProtoNonnullApi;
-import javaemul.internal.annotations.KtNative;
 
-@KtNative
 @ProtoNonnullApi
 public enum MyEnum implements EnumLite {
   ONE,
   TWO;
 
+  @Override
   public int getNumber() {
     throw new RuntimeException();
   }

transpiler/javatests/com/google/j2cl/readable/java/protobuf/MyMessage.java

@@ -18,7 +18,6 @@
 import com.google.protobuf.GeneratedMessage;
 import com.google.protobuf.Internal.ProtoNonnullApi;
 import com.google.protobuf.Parser;
-import javaemul.internal.annotations.KtNative;
 import org.jspecify.annotations.NullMarked;
 
 /**
@@ -36,7 +35,6 @@
  * }</pre>
  */
 @ProtoNonnullApi
-@KtNative
 @NullMarked
 public class MyMessage extends GeneratedMessage {
   public Parser<MyMessage> getParserForType() {

transpiler/javatests/com/google/j2cl/readable/java/protobuf/Parser.java

@@ -15,10 +15,7 @@
  */
 package com.google.protobuf;
 
-import javaemul.internal.annotations.KtNative;
-import javaemul.internal.annotations.KtOut;
 import org.jspecify.annotations.NullMarked;
 
-@KtNative
 @NullMarked
-public class Parser<@KtOut T> {}
+public class Parser<T> {}