javakit: Add more runtime tests for arrays to the sample app (#703)

Author: ktoso

Samples/JavaKitSampleApp/Sources/JavaKitExample/com/example/swift/HelloJavaKitArrays.java

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+package com.example.swift;
+
+public class HelloJavaKitArrays {
+
+    public byte[] getFixedBytes() {
+        return new byte[] { 1, 2, 3, 4, 5 };
+    }
+
+    public byte[] getEmptyBytes() {
+        return new byte[0];
+    }
+
+    public byte[] filledBytes(int size, byte value) {
+        byte[] result = new byte[size];
+        java.util.Arrays.fill(result, value);
+        return result;
+    }
+
+    public byte[] reverseBytes(byte[] input) {
+        byte[] result = new byte[input.length];
+        for (int i = 0; i < input.length; i++) {
+            result[i] = input[input.length - 1 - i];
+        }
+        return result;
+    }
+
+    public int[] getFixedInts() {
+        return new int[] { 100, 200, 300 };
+    }
+
+    public long[] doubleLongs(long[] input) {
+        long[] result = new long[input.length * 2];
+        System.arraycopy(input, 0, result, 0, input.length);
+        System.arraycopy(input, 0, result, input.length, input.length);
+        return result;
+    }
+
+    public byte[] stringToBytes(String s) {
+        return s.getBytes(java.nio.charset.StandardCharsets.UTF_8);
+    }
+
+    public String[] getGreetings() {
+        return new String[] { "hello", "world", "from", "java" };
+    }
+}

Samples/JavaKitSampleApp/Sources/JavaKitExample/swift-java.config

@@ -2,6 +2,7 @@
   "classes" : {
     "com.example.swift.HelloSwift" : "HelloSwift",
     "com.example.swift.HelloSubclass" : "HelloSubclass",
+    "com.example.swift.HelloJavaKitArrays" : "HelloJavaKitArrays",
     "com.example.swift.JavaKitSampleMain" : "JavaKitSampleMain",
     "com.example.swift.ThreadSafeHelperClass" : "ThreadSafeHelperClass"
   }

Samples/JavaKitSampleApp/Tests/JavaKitExampleTests/JavaKitArrayRuntimeTests.swift

@@ -0,0 +1,96 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import JavaKitExample
+import SwiftJava
+import Testing
+
+@Suite
+struct JavaKitArrayRuntimeTests {
+
+  let jvm = try JavaKitSampleJVM.shared
+
+  @Test
+  func getFixedBytes() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let bytes: [Int8] = arrays.getFixedBytes()
+    #expect(bytes == [1, 2, 3, 4, 5])
+  }
+
+  @Test
+  func getEmptyBytes() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let bytes: [Int8] = arrays.getEmptyBytes()
+    #expect(bytes.isEmpty)
+  }
+
+  @Test
+  func filledBytes() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let bytes: [Int8] = arrays.filledBytes(4, 42)
+    #expect(bytes == [42, 42, 42, 42])
+  }
+
+  @Test
+  func reverseBytes() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let reversed: [Int8] = arrays.reverseBytes([10, 20, 30])
+    #expect(reversed == [30, 20, 10])
+  }
+
+  @Test
+  func getFixedInts() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let ints: [Int32] = arrays.getFixedInts()
+    #expect(ints == [100, 200, 300])
+  }
+
+  @Test
+  func doubleLongs() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let longs: [Int64] = arrays.doubleLongs([1, 2, 3])
+    #expect(longs == [1, 2, 3, 1, 2, 3])
+  }
+
+  @Test
+  func stringToBytes() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let bytes: [Int8] = arrays.stringToBytes("Hi")
+    // "Hi" in UTF-8 is [0x48, 0x69]
+    #expect(bytes == [0x48, 0x69])
+  }
+
+  @Test
+  func getGreetings() throws {
+    let env = try jvm.environment()
+    let arrays = HelloJavaKitArrays(environment: env)
+
+    let greetings: [String] = arrays.getGreetings()
+    #expect(greetings == ["hello", "world", "from", "java"])
+  }
+}