feat: id gen comparison test

backend/src/main/java/com/github/binpastes/util/IdGenerator.java

@@ -8,9 +8,13 @@
 public final class IdGenerator {
 
     public static String randomAlphaNumericalId() {
+        return randomAlphaNumericalId(UUID.randomUUID().toString().getBytes());
+    }
+
+    public static String randomAlphaNumericalId(byte[] bytes) {
         try {
             final MessageDigest crypt = MessageDigest.getInstance("SHA-1");
-            crypt.update(UUID.randomUUID().toString().getBytes());
+            crypt.update(bytes);
             return new BigInteger(1, crypt.digest()).toString(16);
         } catch (NoSuchAlgorithmException e) {
             throw new RuntimeException(e);

backend/src/test/java/com/github/binpastes/util/IdGeneratorTest.java

@@ -0,0 +1,18 @@
+package com.github.binpastes.util;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class IdGeneratorTest {
+
+    @Test
+    void sha1Hex() {
+        var uuidv4 = UUID.fromString("9b1482c6-5310-4eef-b91d-75220eb2bef7");
+        var id = IdGenerator.randomAlphaNumericalId(uuidv4.toString().getBytes());
+
+        assertThat(id).isEqualTo("7870235b55ee013737d015c756c02f5efa6ba903");
+    }
+}