diff --git a/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.java b/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.java
deleted file mode 100644
index 0bb4880a43..0000000000
--- a/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.java
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright 2023 Signal Messenger, LLC
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-package org.signal.core.util.logging;
-
-import org.junit.Assert;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-
-public final class LogTest {
-
-  @Test
-  public void tag_short_class_name() {
-    assertEquals("MyClass", Log.tag(MyClass.class));
-  }
-
-  @Test
-  public void tag_23_character_class_name() {
-    String tag = Log.tag(TwentyThreeCharacters23.class);
-    Assert.assertEquals("TwentyThreeCharacters23", tag);
-    Assert.assertEquals(23, tag.length());
-  }
-
-  @Test
-  public void tag_24_character_class_name() {
-    Assert.assertEquals(24, TwentyFour24Characters24.class.getSimpleName().length());
-    String tag = Log.tag(TwentyFour24Characters24.class);
-    Assert.assertEquals("TwentyFour24Characters2", tag);
-    assertEquals(23, Log.tag(TwentyThreeCharacters23.class).length());
-  }
-
-  private class MyClass {
-  }
-
-  private class TwentyThreeCharacters23 {
-  }
-
-  private class TwentyFour24Characters24 {
-  }
-}
diff --git a/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.kt b/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.kt
new file mode 100644
index 0000000000..ebb4d64374
--- /dev/null
+++ b/core-util-jvm/src/test/java/org/signal/core/util/logging/LogTest.kt
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+package org.signal.core.util.logging
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class LogTest {
+  @Test
+  fun tag_short_class_name() {
+    assertEquals("MyClass", Log.tag(MyClass::class))
+  }
+
+  @Test
+  fun tag_23_character_class_name() {
+    val tag = Log.tag(TwentyThreeCharacters23::class)
+    assertEquals("TwentyThreeCharacters23", tag)
+    assertEquals(23, tag.length)
+  }
+
+  @Test
+  fun tag_24_character_class_name() {
+    assertEquals(24, TwentyFour24Characters24::class.simpleName!!.length)
+    val tag = Log.tag(TwentyFour24Characters24::class)
+    assertEquals("TwentyFour24Characters2", tag)
+    assertEquals(23, Log.tag(TwentyThreeCharacters23::class).length)
+  }
+
+  private inner class MyClass
+
+  private inner class TwentyThreeCharacters23
+
+  private inner class TwentyFour24Characters24
+}
diff --git a/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.java b/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.java
deleted file mode 100644
index 1d5dda3584..0000000000
--- a/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.java
+++ /dev/null
@@ -1,104 +0,0 @@
-package org.signal.core.util;
-
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import static java.util.Arrays.asList;
-import static org.junit.Assert.assertEquals;
-
-public final class BreakIteratorCompatTest {
-
-  @Test
-  public void empty() {
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText("");
-
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void single() {
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText("a");
-
-    assertEquals(1, breakIterator.next());
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void count_empty() {
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText("");
-
-    assertEquals(0, breakIterator.countBreaks());
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void count_simple_text() {
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText("abc");
-
-    assertEquals(3, breakIterator.countBreaks());
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void two_counts() {
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText("abc");
-
-    assertEquals(3, breakIterator.countBreaks());
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-    assertEquals(3, breakIterator.countBreaks());
-  }
-
-  @Test
-  public void count_multi_character_graphemes() {
-    String hindi = "समाजो गयेग";
-
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText(hindi);
-
-    assertEquals(7, breakIterator.countBreaks());
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void iterate_multi_character_graphemes() {
-    String hindi = "समाजो गयेग";
-
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText(hindi);
-
-    assertEquals(asList("स", "मा", "जो", " ", "ग", "ये", "ग"), toList(breakIterator));
-    assertEquals(BreakIteratorCompat.DONE, breakIterator.next());
-  }
-
-  @Test
-  public void split_multi_character_graphemes() {
-    String hindi = "समाजो गयेग";
-
-    BreakIteratorCompat breakIterator = BreakIteratorCompat.getInstance();
-    breakIterator.setText(hindi);
-
-    assertEquals("समाजो गयेग", breakIterator.take(8));
-    assertEquals("समाजो गयेग", breakIterator.take(7));
-    assertEquals("समाजो गये", breakIterator.take(6));
-    assertEquals("समाजो ग", breakIterator.take(5));
-    assertEquals("समाजो ", breakIterator.take(4));
-    assertEquals("समाजो", breakIterator.take(3));
-    assertEquals("समा", breakIterator.take(2));
-    assertEquals("स", breakIterator.take(1));
-    assertEquals("", breakIterator.take(0));
-    assertEquals("", breakIterator.take(-1));
-  }
-
-  private List<CharSequence> toList(BreakIteratorCompat breakIterator) {
-    List<CharSequence> list = new ArrayList<>();
-    breakIterator.forEach(list::add);
-    return list;
-  }
-}
diff --git a/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.kt b/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.kt
new file mode 100644
index 0000000000..42fd22f20a
--- /dev/null
+++ b/core-util/src/test/java/org/signal/core/util/BreakIteratorCompatTest.kt
@@ -0,0 +1,92 @@
+package org.signal.core.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class BreakIteratorCompatTest {
+  @Test
+  fun empty() {
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText("")
+
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun single() {
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText("a")
+
+    assertEquals(1, breakIterator.next())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun count_empty() {
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText("")
+
+    assertEquals(0, breakIterator.countBreaks())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun count_simple_text() {
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText("abc")
+
+    assertEquals(3, breakIterator.countBreaks())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun two_counts() {
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText("abc")
+
+    assertEquals(3, breakIterator.countBreaks())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+    assertEquals(3, breakIterator.countBreaks())
+  }
+
+  @Test
+  fun count_multi_character_graphemes() {
+    val hindi = "समाजो गयेग"
+
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText(hindi)
+
+    assertEquals(7, breakIterator.countBreaks())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun iterate_multi_character_graphemes() {
+    val hindi = "समाजो गयेग"
+
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText(hindi)
+
+    assertEquals(listOf("स", "मा", "जो", " ", "ग", "ये", "ग"), breakIterator.toList())
+    assertEquals(BreakIteratorCompat.DONE, breakIterator.next())
+  }
+
+  @Test
+  fun split_multi_character_graphemes() {
+    val hindi = "समाजो गयेग"
+
+    val breakIterator = BreakIteratorCompat.getInstance()
+    breakIterator.setText(hindi)
+
+    assertEquals("समाजो गयेग", breakIterator.take(8))
+    assertEquals("समाजो गयेग", breakIterator.take(7))
+    assertEquals("समाजो गये", breakIterator.take(6))
+    assertEquals("समाजो ग", breakIterator.take(5))
+    assertEquals("समाजो ", breakIterator.take(4))
+    assertEquals("समाजो", breakIterator.take(3))
+    assertEquals("समा", breakIterator.take(2))
+    assertEquals("स", breakIterator.take(1))
+    assertEquals("", breakIterator.take(0))
+    assertEquals("", breakIterator.take(-1))
+  }
+}
diff --git a/core-util/src/test/java/org/signal/core/util/ListUtilTest.java b/core-util/src/test/java/org/signal/core/util/ListUtilTest.java
deleted file mode 100644
index 47395f9d25..0000000000
--- a/core-util/src/test/java/org/signal/core/util/ListUtilTest.java
+++ /dev/null
@@ -1,52 +0,0 @@
-package org.signal.core.util;
-
-import org.junit.Test;
-
-import java.util.Arrays;
-import java.util.List;
-
-import static org.junit.Assert.assertEquals;
-
-public class ListUtilTest {
-
-  @Test
-  public void chunk_oneChunk() {
-    List<String> input = Arrays.asList("A", "B", "C");
-
-    List<List<String>> output = ListUtil.chunk(input, 3);
-    assertEquals(1, output.size());
-    assertEquals(input, output.get(0));
-
-    output = ListUtil.chunk(input, 4);
-    assertEquals(1, output.size());
-    assertEquals(input, output.get(0));
-
-    output = ListUtil.chunk(input, 100);
-    assertEquals(1, output.size());
-    assertEquals(input, output.get(0));
-  }
-
-  @Test
-  public void chunk_multipleChunks() {
-    List<String> input = Arrays.asList("A", "B", "C", "D", "E");
-
-    List<List<String>> output = ListUtil.chunk(input, 4);
-    assertEquals(2, output.size());
-    assertEquals(Arrays.asList("A", "B", "C", "D"), output.get(0));
-    assertEquals(Arrays.asList("E"), output.get(1));
-
-    output = ListUtil.chunk(input, 2);
-    assertEquals(3, output.size());
-    assertEquals(Arrays.asList("A", "B"), output.get(0));
-    assertEquals(Arrays.asList("C", "D"), output.get(1));
-    assertEquals(Arrays.asList("E"), output.get(2));
-
-    output = ListUtil.chunk(input, 1);
-    assertEquals(5, output.size());
-    assertEquals(Arrays.asList("A"), output.get(0));
-    assertEquals(Arrays.asList("B"), output.get(1));
-    assertEquals(Arrays.asList("C"), output.get(2));
-    assertEquals(Arrays.asList("D"), output.get(3));
-    assertEquals(Arrays.asList("E"), output.get(4));
-  }
-}
diff --git a/core-util/src/test/java/org/signal/core/util/ListUtilTest.kt b/core-util/src/test/java/org/signal/core/util/ListUtilTest.kt
new file mode 100644
index 0000000000..8099ca8c59
--- /dev/null
+++ b/core-util/src/test/java/org/signal/core/util/ListUtilTest.kt
@@ -0,0 +1,47 @@
+package org.signal.core.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ListUtilTest {
+  @Test
+  fun chunk_oneChunk() {
+    val input = listOf("A", "B", "C")
+
+    var output = ListUtil.chunk(input, 3)
+    assertEquals(1, output.size)
+    assertEquals(input, output[0])
+
+    output = ListUtil.chunk(input, 4)
+    assertEquals(1, output.size)
+    assertEquals(input, output[0])
+
+    output = ListUtil.chunk(input, 100)
+    assertEquals(1, output.size)
+    assertEquals(input, output[0])
+  }
+
+  @Test
+  fun chunk_multipleChunks() {
+    val input: List<String> = listOf("A", "B", "C", "D", "E")
+
+    var output = ListUtil.chunk(input, 4)
+    assertEquals(2, output.size)
+    assertEquals(listOf("A", "B", "C", "D"), output[0])
+    assertEquals(listOf("E"), output[1])
+
+    output = ListUtil.chunk(input, 2)
+    assertEquals(3, output.size)
+    assertEquals(listOf("A", "B"), output[0])
+    assertEquals(listOf("C", "D"), output[1])
+    assertEquals(listOf("E"), output[2])
+
+    output = ListUtil.chunk(input, 1)
+    assertEquals(5, output.size)
+    assertEquals(listOf("A"), output[0])
+    assertEquals(listOf("B"), output[1])
+    assertEquals(listOf("C"), output[2])
+    assertEquals(listOf("D"), output[3])
+    assertEquals(listOf("E"), output[4])
+  }
+}
diff --git a/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.java b/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.java
deleted file mode 100644
index a883c0e169..0000000000
--- a/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.java
+++ /dev/null
@@ -1,107 +0,0 @@
-package org.signal.core.util.money;
-
-import org.junit.Test;
-
-import java.math.BigDecimal;
-import java.util.Currency;
-
-import static org.junit.Assert.assertEquals;
-
-public class FiatMoneyTest {
-
-  @Test
-  public void given100USD_whenIGetDefaultPrecisionString_thenIExpect100dot00() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("USD"));
-
-    // WHEN
-    String result = fiatMoney.getDefaultPrecisionString();
-
-    // THEN
-    assertEquals("100.00", result);
-  }
-
-  @Test
-  public void given100USD_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("USD"));
-
-    // WHEN
-    String result = fiatMoney.getMinimumUnitPrecisionString();
-
-    // THEN
-    assertEquals("10000", result);
-  }
-
-  @Test
-  public void given100JPY_whenIGetDefaultPrecisionString_thenIExpect100() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("JPY"));
-
-    // WHEN
-    String result = fiatMoney.getDefaultPrecisionString();
-
-    // THEN
-    assertEquals("100", result);
-  }
-
-  @Test
-  public void given100JPY_whenIGetMinimumUnitPrecisionString_thenIExpect100() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("JPY"));
-
-    // WHEN
-    String result = fiatMoney.getMinimumUnitPrecisionString();
-
-    // THEN
-    assertEquals("100", result);
-  }
-
-  @Test
-  public void given100UGX_whenIGetDefaultPrecisionString_thenIExpect100() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("UGX"));
-
-    // WHEN
-    String result = fiatMoney.getDefaultPrecisionString();
-
-    // THEN
-    assertEquals("100", result);
-  }
-
-  @Test
-  public void given100UGX_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("UGX"));
-
-    // WHEN
-    String result = fiatMoney.getMinimumUnitPrecisionString();
-
-    // THEN
-    assertEquals("10000", result);
-  }
-
-  @Test
-  public void given100ISK_whenIGetDefaultPrecisionString_thenIExpect100() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("ISK"));
-
-    // WHEN
-    String result = fiatMoney.getDefaultPrecisionString();
-
-    // THEN
-    assertEquals("100", result);
-  }
-
-  @Test
-  public void given100ISK_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
-    // GIVEN
-    FiatMoney fiatMoney = new FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("ISK"));
-
-    // WHEN
-    String result = fiatMoney.getMinimumUnitPrecisionString();
-
-    // THEN
-    assertEquals("10000", result);
-  }
-}
\ No newline at end of file
diff --git a/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.kt b/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.kt
new file mode 100644
index 0000000000..06bd731936
--- /dev/null
+++ b/core-util/src/test/java/org/signal/core/util/money/FiatMoneyTest.kt
@@ -0,0 +1,104 @@
+package org.signal.core.util.money
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import java.math.BigDecimal
+import java.util.Currency
+
+class FiatMoneyTest {
+  @Test
+  fun given100USD_whenIGetDefaultPrecisionString_thenIExpect100dot00() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("USD"))
+
+    // WHEN
+    val result = fiatMoney.defaultPrecisionString
+
+    // THEN
+    assertEquals("100.00", result)
+  }
+
+  @Test
+  fun given100USD_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("USD"))
+
+    // WHEN
+    val result = fiatMoney.minimumUnitPrecisionString
+
+    // THEN
+    assertEquals("10000", result)
+  }
+
+  @Test
+  fun given100JPY_whenIGetDefaultPrecisionString_thenIExpect100() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("JPY"))
+
+    // WHEN
+    val result = fiatMoney.defaultPrecisionString
+
+    // THEN
+    assertEquals("100", result)
+  }
+
+  @Test
+  fun given100JPY_whenIGetMinimumUnitPrecisionString_thenIExpect100() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("JPY"))
+
+    // WHEN
+    val result = fiatMoney.minimumUnitPrecisionString
+
+    // THEN
+    assertEquals("100", result)
+  }
+
+  @Test
+  fun given100UGX_whenIGetDefaultPrecisionString_thenIExpect100() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("UGX"))
+
+    // WHEN
+    val result = fiatMoney.defaultPrecisionString
+
+    // THEN
+    assertEquals("100", result)
+  }
+
+  @Test
+  fun given100UGX_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("UGX"))
+
+    // WHEN
+    val result = fiatMoney.minimumUnitPrecisionString
+
+    // THEN
+    assertEquals("10000", result)
+  }
+
+  @Test
+  fun given100ISK_whenIGetDefaultPrecisionString_thenIExpect100() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("ISK"))
+
+    // WHEN
+    val result = fiatMoney.defaultPrecisionString
+
+    // THEN
+    assertEquals("100", result)
+  }
+
+  @Test
+  fun given100ISK_whenIGetMinimumUnitPrecisionString_thenIExpect10000() {
+    // GIVEN
+    val fiatMoney = FiatMoney(BigDecimal.valueOf(100), Currency.getInstance("ISK"))
+
+    // WHEN
+    val result = fiatMoney.minimumUnitPrecisionString
+
+    // THEN
+    assertEquals("10000", result)
+  }
+}
diff --git a/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.java b/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.java
deleted file mode 100644
index 7106f9ea28..0000000000
--- a/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.java
+++ /dev/null
@@ -1,89 +0,0 @@
-package org.signal.devicetransfer;
-
-import androidx.annotation.NonNull;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.signal.devicetransfer.DeviceTransferAuthentication.Client;
-import org.signal.devicetransfer.DeviceTransferAuthentication.DeviceTransferAuthenticationException;
-import org.signal.devicetransfer.DeviceTransferAuthentication.Server;
-
-import java.util.Random;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-import static org.whispersystems.signalservice.test.LibSignalLibraryUtil.assumeLibSignalSupportedOnOS;
-
-public class DeviceTransferAuthenticationTest {
-
-  private byte[] certificate;
-
-  @Before
-  public void ensureNativeSupported() throws KeyGenerationFailedException {
-    assumeLibSignalSupportedOnOS();
-
-    certificate = SelfSignedIdentity.create().getX509Encoded();
-  }
-
-  @Test
-  public void testCompute_withNoChanges() throws DeviceTransferAuthenticationException {
-    Client client = new Client(certificate);
-    Server server = new Server(certificate, client.getCommitment());
-
-    byte[] clientRandom = client.setServerRandomAndGetClientRandom(server.getRandom());
-
-    server.setClientRandom(clientRandom);
-    assertEquals(client.computeShortAuthenticationCode(), server.computeShortAuthenticationCode());
-  }
-
-  @Test(expected = DeviceTransferAuthenticationException.class)
-  public void testServerCompute_withChangedClientCertificate() throws DeviceTransferAuthenticationException, KeyGenerationFailedException {
-    byte[] badCertificate = SelfSignedIdentity.create().getX509Encoded();
-    Client client         = new Client(badCertificate);
-    Server server         = new Server(certificate, client.getCommitment());
-
-    byte[] clientRandom = client.setServerRandomAndGetClientRandom(server.getRandom());
-
-    server.setClientRandom(clientRandom);
-    server.computeShortAuthenticationCode();
-  }
-
-  @Test(expected = DeviceTransferAuthenticationException.class)
-  public void testServerCompute_withChangedClientCommitment() throws DeviceTransferAuthenticationException {
-    Client client = new Client(certificate);
-    Server server = new Server(certificate, randomBytes());
-
-    byte[] clientRandom = client.setServerRandomAndGetClientRandom(server.getRandom());
-
-    server.setClientRandom(clientRandom);
-    server.computeShortAuthenticationCode();
-  }
-
-  @Test(expected = DeviceTransferAuthenticationException.class)
-  public void testServerCompute_withChangedClientRandom() throws DeviceTransferAuthenticationException {
-    Client client = new Client(certificate);
-    Server server = new Server(certificate, client.getCommitment());
-
-    client.setServerRandomAndGetClientRandom(server.getRandom());
-
-    server.setClientRandom(randomBytes());
-    server.computeShortAuthenticationCode();
-  }
-
-  @Test
-  public void testClientCompute_withChangedServerSecret() throws DeviceTransferAuthenticationException {
-    Client client = new Client(certificate);
-    Server server = new Server(certificate, client.getCommitment());
-
-    byte[] clientRandom = client.setServerRandomAndGetClientRandom(randomBytes());
-
-    server.setClientRandom(clientRandom);
-    assertNotEquals(client.computeShortAuthenticationCode(), server.computeShortAuthenticationCode());
-  }
-
-  private @NonNull byte[] randomBytes() {
-    byte[] bytes = new byte[32];
-    new Random().nextBytes(bytes);
-    return bytes;
-  }
-}
diff --git a/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.kt b/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.kt
new file mode 100644
index 0000000000..12598873c5
--- /dev/null
+++ b/device-transfer/lib/src/test/java/org/signal/devicetransfer/DeviceTransferAuthenticationTest.kt
@@ -0,0 +1,82 @@
+package org.signal.devicetransfer
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Before
+import org.junit.Test
+import org.signal.devicetransfer.DeviceTransferAuthentication.DeviceTransferAuthenticationException
+import org.whispersystems.signalservice.test.LibSignalLibraryUtil
+import kotlin.random.Random
+
+class DeviceTransferAuthenticationTest {
+  private lateinit var certificate: ByteArray
+
+  @Before
+  fun ensureNativeSupported() {
+    LibSignalLibraryUtil.assumeLibSignalSupportedOnOS()
+
+    certificate = SelfSignedIdentity.create().x509Encoded
+  }
+
+  @Test
+  fun testCompute_withNoChanges() {
+    val client = DeviceTransferAuthentication.Client(certificate)
+    val server = DeviceTransferAuthentication.Server(certificate, client.commitment)
+
+    val clientRandom = client.setServerRandomAndGetClientRandom(server.random)
+
+    server.setClientRandom(clientRandom)
+    assertEquals(client.computeShortAuthenticationCode(), server.computeShortAuthenticationCode())
+  }
+
+  @Test(expected = DeviceTransferAuthenticationException::class)
+  fun testServerCompute_withChangedClientCertificate() {
+    val badCertificate = SelfSignedIdentity.create().x509Encoded
+    val client = DeviceTransferAuthentication.Client(badCertificate)
+    val server = DeviceTransferAuthentication.Server(certificate, client.commitment)
+
+    val clientRandom = client.setServerRandomAndGetClientRandom(server.random)
+
+    server.setClientRandom(clientRandom)
+    server.computeShortAuthenticationCode()
+  }
+
+  @Test(expected = DeviceTransferAuthenticationException::class)
+  fun testServerCompute_withChangedClientCommitment() {
+    val client = DeviceTransferAuthentication.Client(certificate)
+    val server = DeviceTransferAuthentication.Server(certificate, randomBytes())
+
+    val clientRandom = client.setServerRandomAndGetClientRandom(server.random)
+
+    server.setClientRandom(clientRandom)
+    server.computeShortAuthenticationCode()
+  }
+
+  @Test(expected = DeviceTransferAuthenticationException::class)
+  fun testServerCompute_withChangedClientRandom() {
+    val client = DeviceTransferAuthentication.Client(certificate)
+    val server = DeviceTransferAuthentication.Server(certificate, client.commitment)
+
+    client.setServerRandomAndGetClientRandom(server.random)
+
+    server.setClientRandom(randomBytes())
+    server.computeShortAuthenticationCode()
+  }
+
+  @Test
+  fun testClientCompute_withChangedServerSecret() {
+    val client = DeviceTransferAuthentication.Client(certificate)
+    val server = DeviceTransferAuthentication.Server(certificate, client.commitment)
+
+    val clientRandom = client.setServerRandomAndGetClientRandom(randomBytes())
+
+    server.setClientRandom(clientRandom)
+    assertNotEquals(client.computeShortAuthenticationCode(), server.computeShortAuthenticationCode())
+  }
+
+  private fun randomBytes(): ByteArray {
+    val bytes = ByteArray(32)
+    Random.nextBytes(bytes)
+    return bytes
+  }
+}
diff --git a/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.java b/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.java
deleted file mode 100644
index 5b64cdd7af..0000000000
--- a/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.java
+++ /dev/null
@@ -1,42 +0,0 @@
-package org.signal.devicetransfer;
-
-import android.app.Application;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.robolectric.RobolectricTestRunner;
-import org.robolectric.annotation.Config;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-
-@RunWith(RobolectricTestRunner.class)
-@Config(manifest = Config.NONE, application = Application.class)
-public class WifiDirectTest {
-
-  @Test
-  public void instanceName_withExtraInfo() {
-    String instanceName = WifiDirect.buildServiceInstanceName("knownothing");
-
-    assertEquals("_devicetransfer._knownothing._signal.org", instanceName);
-
-    String extractedExtraInfo = WifiDirect.isInstanceNameMatching(instanceName);
-    assertEquals(extractedExtraInfo, "knownothing");
-  }
-
-  @Test
-  public void instanceName_matchingWithoutExtraInfo() {
-    String instanceName = WifiDirect.buildServiceInstanceName("");
-
-    assertEquals("_devicetransfer._signal.org", instanceName);
-
-    String extractedExtraInfo = WifiDirect.isInstanceNameMatching(instanceName);
-    assertEquals(extractedExtraInfo, "");
-  }
-
-  @Test
-  public void instanceName_notMatching() {
-    String extractedExtraInfo = WifiDirect.isInstanceNameMatching("_whoknows._what.org");
-    assertNull(extractedExtraInfo);
-  }
-}
\ No newline at end of file
diff --git a/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.kt b/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.kt
new file mode 100644
index 0000000000..e5eb264574
--- /dev/null
+++ b/device-transfer/lib/src/test/java/org/signal/devicetransfer/WifiDirectTest.kt
@@ -0,0 +1,39 @@
+package org.signal.devicetransfer
+
+import android.app.Application
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+@Config(manifest = Config.NONE, application = Application::class)
+class WifiDirectTest {
+  @Test
+  fun instanceName_withExtraInfo() {
+    val instanceName = WifiDirect.buildServiceInstanceName("knownothing")
+
+    assertEquals("_devicetransfer._knownothing._signal.org", instanceName)
+
+    val extractedExtraInfo = WifiDirect.isInstanceNameMatching(instanceName)
+    assertEquals(extractedExtraInfo, "knownothing")
+  }
+
+  @Test
+  fun instanceName_matchingWithoutExtraInfo() {
+    val instanceName = WifiDirect.buildServiceInstanceName("")
+
+    assertEquals("_devicetransfer._signal.org", instanceName)
+
+    val extractedExtraInfo = WifiDirect.isInstanceNameMatching(instanceName)
+    assertEquals(extractedExtraInfo, "")
+  }
+
+  @Test
+  fun instanceName_notMatching() {
+    val extractedExtraInfo = WifiDirect.isInstanceNameMatching("_whoknows._what.org")
+    assertNull(extractedExtraInfo)
+  }
+}
diff --git a/donations/app/src/main/res/layout/activity_main.xml b/donations/app/src/main/res/layout/activity_main.xml
index b07556fbe9..4dfdd065d2 100644
--- a/donations/app/src/main/res/layout/activity_main.xml
+++ b/donations/app/src/main/res/layout/activity_main.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
diff --git a/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.java b/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.java
deleted file mode 100644
index 58310f57d0..0000000000
--- a/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package org.whispersystems.util;
-
-import org.junit.Assert;
-import org.junit.Test;
-
-public class FlagUtilTest {
-
-  @Test
-  public void given1_whenIConvertToBinaryFlag_thenIExpect1() {
-    int expected = 1;
-
-    int actual = FlagUtil.toBinaryFlag(1);
-
-    Assert.assertEquals(expected, actual);
-  }
-
-
-  @Test
-  public void given2_whenIConvertToBinaryFlag_thenIExpect2() {
-    int expected = 2;
-
-    int actual = FlagUtil.toBinaryFlag(2);
-
-    Assert.assertEquals(expected, actual);
-  }
-
-  @Test
-  public void given3_whenIConvertToBinaryFlag_thenIExpect4() {
-    int expected = 4;
-
-    int actual = FlagUtil.toBinaryFlag(3);
-
-    Assert.assertEquals(expected, actual);
-  }
-}
\ No newline at end of file
diff --git a/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.kt b/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.kt
new file mode 100644
index 0000000000..fb8efb70d4
--- /dev/null
+++ b/libsignal-service/src/test/java/org/whispersystems/util/FlagUtilTest.kt
@@ -0,0 +1,21 @@
+package org.whispersystems.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class FlagUtilTest {
+  @Test
+  fun given1_whenIConvertToBinaryFlag_thenIExpect1() {
+    assertEquals(1, FlagUtil.toBinaryFlag(1))
+  }
+
+  @Test
+  fun given2_whenIConvertToBinaryFlag_thenIExpect2() {
+    assertEquals(2, FlagUtil.toBinaryFlag(2))
+  }
+
+  @Test
+  fun given3_whenIConvertToBinaryFlag_thenIExpect4() {
+    assertEquals(4, FlagUtil.toBinaryFlag(3))
+  }
+}
diff --git a/paging/lib/src/test/java/org/signal/paging/DataStatusTest.java b/paging/lib/src/test/java/org/signal/paging/DataStatusTest.java
deleted file mode 100644
index 604a777490..0000000000
--- a/paging/lib/src/test/java/org/signal/paging/DataStatusTest.java
+++ /dev/null
@@ -1,58 +0,0 @@
-package org.signal.paging;
-
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-public class DataStatusTest {
-
-  @Test
-  public void insertState_initiallyEmpty_InsertAtZero() {
-    DataStatus subject = DataStatus.obtain(0);
-    subject.insertState(0, true);
-
-    assertEquals(1, subject.size());
-    assertTrue(subject.get(0));
-  }
-
-  @Test
-  public void insertState_someData_InsertAtZero() {
-    DataStatus subject = DataStatus.obtain(2);
-    subject.mark(1);
-
-    subject.insertState(0, true);
-
-    assertEquals(3, subject.size());
-    assertTrue(subject.get(0));
-    assertFalse(subject.get(1));
-    assertTrue(subject.get(2));
-  }
-
-  @Test
-  public void insertState_someData_InsertAtOne() {
-    DataStatus subject = DataStatus.obtain(3);
-    subject.mark(1);
-
-    subject.insertState(1, true);
-
-    assertEquals(4, subject.size());
-    assertFalse(subject.get(0));
-    assertTrue(subject.get(1));
-    assertTrue(subject.get(2));
-    assertFalse(subject.get(3));
-  }
-
-  @Test(expected = IndexOutOfBoundsException.class)
-  public void insertState_negativeThrows() {
-    DataStatus subject = DataStatus.obtain(0);
-    subject.insertState(-1, true);
-  }
-
-  @Test(expected = IndexOutOfBoundsException.class)
-  public void insertState_largerThanSizePlusOneThrows() {
-    DataStatus subject = DataStatus.obtain(0);
-    subject.insertState(2, true);
-  }
-}
diff --git a/paging/lib/src/test/java/org/signal/paging/DataStatusTest.kt b/paging/lib/src/test/java/org/signal/paging/DataStatusTest.kt
new file mode 100644
index 0000000000..5f8a2ce2f5
--- /dev/null
+++ b/paging/lib/src/test/java/org/signal/paging/DataStatusTest.kt
@@ -0,0 +1,56 @@
+package org.signal.paging
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class DataStatusTest {
+  @Test
+  fun insertState_initiallyEmpty_InsertAtZero() {
+    val subject = DataStatus.obtain(0)
+    subject.insertState(0, true)
+
+    assertEquals(1, subject.size())
+    assertTrue(subject[0])
+  }
+
+  @Test
+  fun insertState_someData_InsertAtZero() {
+    val subject = DataStatus.obtain(2)
+    subject.mark(1)
+
+    subject.insertState(0, true)
+
+    assertEquals(3, subject.size())
+    assertTrue(subject[0])
+    assertFalse(subject[1])
+    assertTrue(subject[2])
+  }
+
+  @Test
+  fun insertState_someData_InsertAtOne() {
+    val subject = DataStatus.obtain(3)
+    subject.mark(1)
+
+    subject.insertState(1, true)
+
+    assertEquals(4, subject.size())
+    assertFalse(subject[0])
+    assertTrue(subject[1])
+    assertTrue(subject[2])
+    assertFalse(subject[3])
+  }
+
+  @Test(expected = IndexOutOfBoundsException::class)
+  fun insertState_negativeThrows() {
+    val subject = DataStatus.obtain(0)
+    subject.insertState(-1, true)
+  }
+
+  @Test(expected = IndexOutOfBoundsException::class)
+  fun insertState_largerThanSizePlusOneThrows() {
+    val subject = DataStatus.obtain(0)
+    subject.insertState(2, true)
+  }
+}