[android] add basic tests for auto generated java lib (#290)

When the SWIG interface file (commissioner.i) is updated, the generated
java library API may be broken. There are currently no tests to guard
this. This commit adds a basic androidTest for this purpose. Note that
an Android rather than junit test is added because the test case depends
on an JNI library.

.github/workflows/android-app-build.yml

@@ -35,7 +35,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        android-api: [24, 34]
+        android-api: [26, 34]
         android-abi: [x86_64]
         os: [macos-12, ubuntu-22.04]
     steps:

android/openthread_commissioner/service/build.gradle

@@ -81,7 +81,7 @@ dependencies {
     implementation 'com.google.android.gms:play-services-vision:20.1.3+'
     implementation 'com.google.android.gms:play-services-threadnetwork:16.0.0'
     implementation 'com.google.android.material:material:1.2.1'
-    testImplementation 'junit:junit:4.+'
+    androidTestImplementation 'com.google.truth:truth:1.4.4'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0'
 }

android/openthread_commissioner/service/src/androidTest/java/io/openthread/commissioner/ActiveOperationalDatasetTest.java

@@ -0,0 +1,34 @@
+package io.openthread.commissioner;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.util.stream.Collectors;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public final class ActiveOperationalDatasetTest {
+  @Test
+  public void channelMask_valuesAreCorrect() {
+    ActiveOperationalDataset dataset = new ActiveOperationalDataset();
+    ChannelMaskEntry entry1 = new ChannelMaskEntry();
+    entry1.setPage((short) 0);
+    entry1.setMasks(new ByteArray(new byte[] {0x01, 0x02, 0x03, 0x04}));
+    ChannelMaskEntry entry2 = new ChannelMaskEntry();
+    entry2.setPage((short) 1);
+    entry2.setMasks(new ByteArray(new byte[] {0x05, 0x06, 0x07, 0x08}));
+    ChannelMask maskEntries = new ChannelMask();
+    maskEntries.add(entry1);
+    maskEntries.add(entry2);
+    dataset.setChannelMask(maskEntries);
+
+    assertThat(dataset.getChannelMask()).hasSize(2);
+    assertThat(dataset.getChannelMask().get(0).getPage()).isEqualTo(0);
+    assertThat(dataset.getChannelMask().get(0).getMasks().stream().collect(Collectors.toList()))
+        .containsExactly((byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04);
+    assertThat(dataset.getChannelMask().get(1).getPage()).isEqualTo(1);
+    assertThat(dataset.getChannelMask().get(1).getMasks().stream().collect(Collectors.toList()))
+        .containsExactly((byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08);
+  }
+}