test: add unit tests for UUIDStringUtils

sentry/src/test/java/io/sentry/util/UUIDStringUtilsTest.kt

@@ -0,0 +1,85 @@
+package io.sentry.util
+
+import java.util.UUID
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class UUIDStringUtilsTest {
+
+  @Test
+  fun `toSentryIdString produces 32-char lowercase hex without dashes`() {
+    val uuid = UUID.fromString("a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11")
+    val result = UUIDStringUtils.toSentryIdString(uuid)
+    assertEquals(32, result.length)
+    assertEquals("a0eebc999c0b4ef8bb6d6bb9bd380a11", result)
+  }
+
+  @Test
+  fun `toSentryIdString handles all-zeros UUID`() {
+    val uuid = UUID(0L, 0L)
+    val result = UUIDStringUtils.toSentryIdString(uuid)
+    assertEquals("00000000000000000000000000000000", result)
+  }
+
+  @Test
+  fun `toSentryIdString handles max-value UUID`() {
+    val uuid = UUID(-1L, -1L) // all bits set = ffffffff-ffff-ffff-ffff-ffffffffffff
+    val result = UUIDStringUtils.toSentryIdString(uuid)
+    assertEquals("ffffffffffffffffffffffffffffffff", result)
+  }
+
+  @Test
+  fun `toSentryIdString from longs matches UUID overload`() {
+    val uuid = UUID.fromString("550e8400-e29b-41d4-a716-446655440000")
+    val fromUuid = UUIDStringUtils.toSentryIdString(uuid)
+    val fromLongs =
+      UUIDStringUtils.toSentryIdString(uuid.mostSignificantBits, uuid.leastSignificantBits)
+    assertEquals(fromUuid, fromLongs)
+  }
+
+  @Test
+  fun `toSentrySpanIdString produces 16-char lowercase hex`() {
+    val uuid = UUID.fromString("a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11")
+    val result = UUIDStringUtils.toSentrySpanIdString(uuid)
+    assertEquals(16, result.length)
+    assertEquals("a0eebc999c0b4ef8", result)
+  }
+
+  @Test
+  fun `toSentrySpanIdString handles all-zeros`() {
+    val uuid = UUID(0L, 0L)
+    val result = UUIDStringUtils.toSentrySpanIdString(uuid)
+    assertEquals("0000000000000000", result)
+  }
+
+  @Test
+  fun `toSentrySpanIdString handles max-value`() {
+    val uuid = UUID(-1L, -1L)
+    val result = UUIDStringUtils.toSentrySpanIdString(uuid)
+    assertEquals("ffffffffffffffff", result)
+  }
+
+  @Test
+  fun `toSentrySpanIdString from long matches UUID overload`() {
+    val uuid = UUID.fromString("550e8400-e29b-41d4-a716-446655440000")
+    val fromUuid = UUIDStringUtils.toSentrySpanIdString(uuid)
+    val fromLong = UUIDStringUtils.toSentrySpanIdString(uuid.mostSignificantBits)
+    assertEquals(fromUuid, fromLong)
+  }
+
+  @Test
+  fun `toSentryIdString uses only lowercase hex digits`() {
+    // UUID with uppercase hex letters in standard form
+    val uuid = UUID.fromString("ABCDEF01-2345-6789-ABCD-EF0123456789")
+    val result = UUIDStringUtils.toSentryIdString(uuid)
+    assertEquals(result, result.lowercase())
+  }
+
+  @Test
+  fun `toSentrySpanIdString is first 16 chars of toSentryIdString`() {
+    val uuid = UUID.fromString("12345678-abcd-ef01-2345-6789abcdef01")
+    val fullId = UUIDStringUtils.toSentryIdString(uuid)
+    val spanId = UUIDStringUtils.toSentrySpanIdString(uuid)
+    assertEquals(fullId.substring(0, 16), spanId)
+  }
+}