✨ IdGenerator can have random overridden

src/main/kotlin/io/andrewohara/utils/IdGenerator.kt

@@ -1,13 +1,14 @@
 package io.andrewohara.utils
 
-import java.security.SecureRandom
+import java.util.Random
 
-object IdGenerator {
+open class IdGenerator(private val random: Random = Random()) {
+
+    companion object: IdGenerator()
 
     private val base36 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray()
     private val numeric = "0123456789".toCharArray()
-    private val hex = "0123456789abcdef".toCharArray()
-    private val random = SecureRandom()
+    private val hex = "0123456789ABCDEF".toCharArray()
 
     private fun next(length: Int, chars: CharArray): String {
         val sb = StringBuilder(length)
@@ -21,5 +22,5 @@ object IdGenerator {
 
     fun nextNumeric(length: Int) = next(length, numeric).toBigInteger()
 
-    fun nextHex(length: Int) = next(length, hex).lowercase()
+    fun nextHex(length: Int) = next(length, hex)
 }

src/test/kotlin/io/andrewohara/utils/IdGeneratorTest.kt

@@ -0,0 +1,33 @@
+package io.andrewohara.utils
+
+import io.kotest.matchers.shouldBe
+import io.kotest.matchers.string.shouldHaveLength
+import org.junit.jupiter.api.Test
+import java.util.Random
+
+class IdGeneratorTest {
+
+    private val testObj = IdGenerator(Random(1337))
+
+    @Test
+    fun `next hex`() {
+        testObj.nextHex(8) shouldBe "19E79D84"
+    }
+
+    @Test
+    fun `next base36`() {
+        testObj.nextBase36(8) shouldBe "QETRJ88E"
+    }
+
+    @Test
+    fun `next numeric`() {
+        testObj.nextNumeric(8) shouldBe 10546784.toBigInteger()
+    }
+
+    @Test
+    fun `companion object`() {
+        IdGenerator.nextHex(4).shouldHaveLength(4)
+        IdGenerator.nextNumeric(4).toString().shouldHaveLength(4)
+        IdGenerator.nextBase36(4).shouldHaveLength(4)
+    }
+}