Create VarIntIteratorTest.kt

Author: emyfops

common/src/test/kotlin/VarIntIteratorTest.kt

@@ -0,0 +1,87 @@
+import com.lambda.util.VarIntIterator
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+/*
+ * Copyright 2025 Lambda
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+class VarIntIteratorTest {
+
+    private lateinit var iterator: VarIntIterator
+
+    @Test
+    fun `test single byte varint`() {
+        val bytes = byteArrayOf(0b01111111.toByte())  // Maximum single-byte VarInt (127)
+        iterator = VarIntIterator(bytes)
+
+        assertTrue(iterator.hasNext())
+        assertEquals(127, iterator.next())
+        assertFalse(iterator.hasNext())  // No more elements after this
+    }
+
+    @Test
+    fun `test multi-byte varint`() {
+        val bytes = byteArrayOf(0b10000001.toByte(), 0b00000001.toByte()) // Represents 129
+        iterator = VarIntIterator(bytes)
+
+        assertTrue(iterator.hasNext())
+        assertEquals(129, iterator.next())
+        assertFalse(iterator.hasNext())  // No more elements after this
+    }
+
+    @Test
+    fun `test varint iterator with multiple values`() {
+        val bytes = byteArrayOf(
+            0b10000001.toByte(), 0b00000001.toByte(),  // 129
+            0b01111111.toByte(),  // 127
+            0b10000000.toByte(), 0b00000001.toByte()   // 128
+        )
+        iterator = VarIntIterator(bytes)
+
+        assertTrue(iterator.hasNext())
+        assertEquals(129, iterator.next())
+        assertTrue(iterator.hasNext())
+        assertEquals(127, iterator.next())
+        assertTrue(iterator.hasNext())
+        assertEquals(128, iterator.next())
+        assertFalse(iterator.hasNext())  // No more elements after this
+    }
+
+    @Test
+    fun `test varint iterator with no elements`() {
+        val bytes = byteArrayOf()  // Empty byte array
+        iterator = VarIntIterator(bytes)
+
+        assertFalse(iterator.hasNext())  // There are no elements
+        assertFails {
+            iterator.next()  // Should throw exception since there are no elements
+        }
+    }
+
+    @Test
+    fun `test reading varint with unexpected end of byte array`() {
+        val bytes = byteArrayOf(0b10000001.toByte())  // Only part of a VarInt
+        iterator = VarIntIterator(bytes)
+
+        assertFails {
+            iterator.next()  // Should throw exception since the VarInt is incomplete
+        }
+    }
+}