fix: return file size in bytes

Author: krizzu

sqlite-storage/src/androidMain/kotlin/org/asyncstorage/sqlitestorage/AndroidDatabaseFile.kt

@@ -33,7 +33,8 @@ internal class AndroidDatabaseFile(private val dbFile: File) : DatabaseFiles {
     override fun size(type: DatabaseFileType): Long? {
         val file = File(path(type))
         return if (file.exists()) {
-            (dbFile.length() / 1024L)
+            val length = dbFile.length()
+            if (length == 0L) return null else length
         } else {
             null
         }

sqlite-storage/src/androidUnitTest/kotlin/org/asyncstorage/sqlitestorage/utils/FileTestHelper.kt

@@ -23,8 +23,8 @@ actual class FileTestHelper actual constructor(path: String) {
         }
     }
 
-    actual fun fillWithChars(charCount: Int) {
-        file.writeText("x".repeat(charCount))
+    actual fun fillWithChars(charCount: Int, char: String) {
+        file.writeText(char.repeat(charCount))
     }
 
     actual fun exists() = file.exists()

sqlite-storage/src/commonMain/kotlin/org/asyncstorage/sqlitestorage/DatabaseFiles.kt

@@ -19,7 +19,7 @@ interface DatabaseFiles {
     fun delete(): Boolean
 
     /**
-     * Returns a size of a selected database file
+     * Returns a size of a selected database file in bytes
      * If the file does not exists or cannot be read for some reason, returns null
      */
     fun size(type: DatabaseFileType = DatabaseFileType.Main): Long?

sqlite-storage/src/commonTest/kotlin/org/asyncstorage/sqlitestorage/DatabaseFileTest.kt

@@ -25,9 +25,10 @@ class DatabaseFileTest {
         val file = createDatabaseFile(dbName)
         val helper = FileTestHelper.createFileAt(file.path())
         assertTrue(helper.exists(), "db file not created")
-        helper.fillWithChars(2048)
-        val size = file.size()
-        assertTrue(size == 2L, "size not matching $size")
+        helper.fillWithChars(500, "a") // 1 byte in UTF8
+        val size1 = file.size()
+        val expected1 = 500L
+        assertEquals(expected1, size1, "size miss match")
     }
 
     @Test

sqlite-storage/src/commonTest/kotlin/org/asyncstorage/sqlitestorage/utils/FileTestHelper.kt

@@ -8,7 +8,7 @@ expect class FileTestHelper(path: String) {
         ): FileTestHelper
     }
 
-    fun fillWithChars(charCount: Int)
+    fun fillWithChars(charCount: Int, char: String = "")
 
     fun exists(): Boolean
 

sqlite-storage/src/iosMain/kotlin/org/asyncstorage/sqlitestorage/IosDatabaseFile.kt

@@ -55,8 +55,8 @@ internal class IosDatabaseFile(private val dbName: String) : DatabaseFiles {
         return try {
             val attrs = NSFileManager.defaultManager.attributesOfItemAtPath(file, null)
             val fileSize = attrs?.get(NSFileSize) as Long?
-            fileSize?.let {
-                it / 1024L
+            fileSize?.let { length ->
+                if (length == 0L) null else length
             }
         } catch (e: Exception) {
             return null

sqlite-storage/src/iosTest/kotlin/org/asyncstorage/sqlitestorage/utils/FileTestHelper.kt

@@ -42,8 +42,8 @@ actual class FileTestHelper actual constructor(path: String) {
         }
     }
 
-    actual fun fillWithChars(charCount: Int) {
-        val content = "x".repeat(charCount)
+    actual fun fillWithChars(charCount: Int, char: String) {
+        val content = char.repeat(charCount)
         try {
             (content as NSString).writeToFile(file, true)
         } catch (e: Throwable) {