Fix kt_android emitting an empty ABI .api dump (#112)

examples/kotlin/.bazelrc

@@ -1,4 +1,10 @@
 common --enable_bzlmod
 
 # Bazel 9: external modules still using bare native symbols. Auto-inject loads.
-common --incompatible_autoload_externally=+@rules_cc,+@rules_shell
+common --incompatible_autoload_externally=+@rules_cc,+@rules_shell
+
+# The rules_android builder tools require a JDK 17 toolchain.
+common --java_language_version=17
+common --java_runtime_version=17
+common --tool_java_language_version=17
+common --tool_java_runtime_version=17

examples/kotlin/.bazelversion

@@ -1 +1 @@
-8.4.2
+9.1.1

examples/kotlin/AndroidLib.kt

@@ -0,0 +1,10 @@
+package com.intuit.bazel.kotlin.android
+
+/** A small public surface so the generated ABI `.api` has recognizable signatures. */
+public class AndroidLib {
+    public val greeting: String = "hello"
+
+    public fun greet(name: String): String = "$greeting, $name"
+
+    public fun add(a: Int, b: Int): Int = a + b
+}

examples/kotlin/BUILD

@@ -1,5 +1,5 @@
 load("@rules_kotlin//kotlin:lint.bzl", "ktlint_config")
-load("@rules_player//kotlin:defs.bzl", "abi_update_all", "kt_jvm", "lint_fix_all")
+load("@rules_player//kotlin:defs.bzl", "abi_update_all", "kt_android", "kt_jvm", "lint_fix_all")
 
 ktlint_config(
     name = "lint_config",
@@ -14,6 +14,16 @@ kt_jvm(
     test_srcs = ["Tests.kt"],
 )
 
+# Regression coverage for #112: the published kt_android target is a
+# source-less android_library wrapper, so the ABI dump must target the
+# underlying kt_android_library base. api_file defaults, generating
+# android_lib-abi-dump / -abi-check / -abi-update.
+kt_android(
+    name = "android_lib",
+    main_srcs = ["AndroidLib.kt"],
+    manifest = "src/main/AndroidManifest.xml",
+)
+
 abi_update_all(
     name = "abi-update-all",
 )

examples/kotlin/MODULE.bazel

@@ -9,7 +9,25 @@ local_path_override(
 )
 
 bazel_dep(name = "rules_kotlin", version = "2.1.8")
-bazel_dep(name = "rules_jvm_external", version = "6.8")
+bazel_dep(name = "rules_java", version = "7.2.0")
+bazel_dep(name = "rules_jvm_external", version = "6.9")
+bazel_dep(name = "rules_android", version = "0.7.2")
+
+# Android tooling + SDK so the kt_android example below can build.
+# The SDK is autodetected from $ANDROID_HOME by android_sdk_repository_extension.
+remote_android_extensions = use_extension(
+    "@rules_android//bzlmod_extensions:android_extensions.bzl",
+    "remote_android_tools_extensions",
+)
+use_repo(remote_android_extensions, "android_tools")
+
+android_sdk_repository_extension = use_extension(
+    "@rules_android//rules/android_sdk_repository:rule.bzl",
+    "android_sdk_repository_extension",
+)
+use_repo(android_sdk_repository_extension, "androidsdk")
+
+register_toolchains("@androidsdk//:sdk-toolchain", "@androidsdk//:all")
 
 maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
 maven.install(
@@ -28,4 +46,4 @@ maven.install(
         "https://plugins.gradle.org/m2/",
     ],
 )
-use_repo(maven, "maven")
+use_repo(maven, "maven")

examples/kotlin/api/android_lib.api

@@ -0,0 +1,7 @@
+public final class com/intuit/bazel/kotlin/android/AndroidLib {
+	public fun <init> ()V
+	public final fun add (II)I
+	public final fun getGreeting ()Ljava/lang/String;
+	public final fun greet (Ljava/lang/String;)Ljava/lang/String;
+}
+

examples/kotlin/src/main/AndroidManifest.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.intuit.bazel.kotlin.android">
+</manifest>

kotlin/private/kt_android.bzl

@@ -168,7 +168,7 @@ def kt_android(
 
     maven_coordinates = "%s:%s:aar:%s" % (group, name, version if version else "{pom_version}") if should_publish else None
 
-    kt_android_library_and_test(
+    base_target = kt_android_library_and_test(
         name = name,
         manifest = manifest,
         tags = ["maven_coordinates=%s" % (maven_coordinates)] if maven_coordinates else None,
@@ -209,7 +209,7 @@ def kt_android(
     if api_file != None:
         abi(
             name = name,
-            target = ":" + name,
+            target = base_target,
             api_file = None if api_file == ABI_FILE_DEFAULT else api_file,
             public_packages = abi_public_packages,
             public_classes = abi_public_classes,

kotlin/private/kt_android_library_and_test.bzl

@@ -133,3 +133,5 @@ def kt_android_library_and_test(
             test_class = test_class,
             deps = instrumented_test_deps,
         )
+
+    return ":" + base_name