Correct conversion between bytes and other units (#347)

hoplite-core/src/main/kotlin/com/sksamuel/hoplite/decoder/SizeInBytesDecoder.kt

@@ -22,7 +22,7 @@ data class SizeInBytes(val size: Long) {
   fun gigabytes() = convert(InformationUnit.Gigabytes)
   fun gibibytes() = convert(InformationUnit.Gibibytes)
 
-  fun convert(unit: InformationUnit): Long = (unit.ratioToPrimary / size).toLong()
+  fun convert(unit: InformationUnit): Long = (size / unit.ratioToPrimary).toLong()
 
   companion object {
     fun parse(input: String): SizeInBytes? {

hoplite-core/src/test/kotlin/com/sksamuel/hoplite/decoder/SizeInBytesDecoderTest.kt

@@ -0,0 +1,24 @@
+package com.sksamuel.hoplite.decoder
+
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+
+class SizeInBytesDecoderTest : FunSpec({
+  val units = listOf(
+    InformationUnit.Kilobytes,
+    InformationUnit.Megabytes,
+    InformationUnit.Gigabytes,
+
+    InformationUnit.Octets,
+    InformationUnit.Kibibytes,
+    InformationUnit.Mebibytes,
+    InformationUnit.Gibibytes
+  )
+
+  test("conversion between bytes and other units") {
+    val size = 8
+    for (unit in units) {
+      SizeInBytes((size * unit.ratioToPrimary).toLong()).convert(unit) shouldBe size
+    }
+  }
+})