fixed according to the comments

src/test/java/core/basesyntax/service/impl/CsvDataReaderTest.java

@@ -8,20 +8,20 @@
 
 public class CsvDataReaderTest {
     private static final String INPUT_VALID_FILE =
-                                "src/test/test-resources/input-files/TestValidInputFile.txt";
+                                "src/test/test-resources/input-files/TestValidInputFile.csv";
     private static final String INPUT_EMPTY_FILE =
-                                "src/test/test-resources/input-files/TestEmptyFile.txt";
+                                "src/test/test-resources/input-files/TestEmptyFile.csv";
     private static final String INPUT_NONEXISTENT_FILE =
                                 "src/test/test-resources/input-files/doesNotExist.txt";
     private static final String INPUT_RANDOM_LINES_FILE =
-                                "src/test/test-resources/input-files/TestRandomLines.txt";
+                                "src/test/test-resources/input-files/TestRandomLines.csv";
     private static final CsvDataReader csvDataReader = new CsvDataReader();
 
     @Test
     public void readFileLines_allValidConditions_Ok() {
         List<String> actual = csvDataReader.readFileLines(INPUT_VALID_FILE);
         List<String> expected = List.of("type,fruit,quantity", "b,banana,20");
-        assertEquals(actual, expected);
+        assertEquals(expected, actual);
     }
 
     @Test
@@ -42,6 +42,6 @@ public void readFileLines_inputWithCustomLines_Ok() {
                                         "fwpueivwrnv",
                                         "vpaerhgp48g  oiwjeiof",
                                         "whvwvoiwn");
-        assertEquals(actual, expected);
+        assertEquals(expected, actual);
     }
 }

src/test/java/core/basesyntax/service/impl/CsvDataWriterTest.java

@@ -12,10 +12,10 @@ public class CsvDataWriterTest {
     private static final String VALID_STRING = "Some VALID STrING";
     private static final String EMPTY_STRING = "";
     private static final String NONEXISTENT_DESTINATION_FILE =
-                                "src/test/test-resources/output-files/nonexistent.txt";
+                                "src/test/test-resources/output-files/nonexistent.csv";
     private static final String VALID_DESTINATION_FILE =
-                                "src/test/test-resources/output-files/TestValidFile.txt";
-    private final CsvDataWriter csvDataWriter = new CsvDataWriter();
+                                "src/test/test-resources/output-files/TestValidFile.csv";
+    private static CsvDataWriter csvDataWriter = new CsvDataWriter();
 
     @Test
     public void writeToFile_allValidConditions_Ok() throws IOException {

src/test/java/core/basesyntax/service/impl/CsvReadDataParserImplTest.java

@@ -20,7 +20,7 @@ public void convertToFruitTransactionList_allValidConditions() {
         FruitTransaction expected = new FruitTransaction(
                                         FruitTransaction.OperationType.BALANCE, "banana", 20);
         FruitTransaction actual = parser.convertToFruitTransactionList(VALID_INPUT).get(0);
-        assertEquals(actual, expected);
+        assertEquals(expected, actual);
     }
 
     @Test

src/test/java/core/basesyntax/service/impl/CsvReportGeneratorTest.java

@@ -10,7 +10,7 @@
 import org.junit.jupiter.api.Test;
 
 public class CsvReportGeneratorTest {
-    private static final String VALID_RESUL_STRING = "fruit,quantity"
+    private static final String VALID_RESULT_STRING = "fruit,quantity"
                                                     + System.lineSeparator()
                                                     + "banana,152";
     private static InventoryDao inventoryDao;
@@ -31,7 +31,7 @@ public void cleanInventory() {
     public void generateReport_allValidConditions() {
         inventoryDao.putToInventory("banana", 152);
         String actual = csvReportGenerator.generateReport();
-        assertEquals(actual, VALID_RESUL_STRING);
+        assertEquals(VALID_RESULT_STRING, actual);
     }
 
     @Test
@@ -49,6 +49,6 @@ public void generateReport_with_RandomDataInInventory_Ok() {
                             + "fruit2," + 2 + System.lineSeparator()
                             + "fruit1," + 1 + System.lineSeparator()
                             + "fruit0," + 0;
-        assertEquals(actual, expected);
+        assertEquals(expected, actual);
     }
 }

src/test/java/core/basesyntax/service/impl/TransactionProcessorImplTest.java

@@ -20,13 +20,14 @@
 import org.junit.jupiter.api.Test;
 
 public class TransactionProcessorImplTest {
-    private static final HandlerStrategy strategy = new HandlerStrategy(new HashMap<>());
+    private static HandlerStrategy strategy;
     private static InventoryDao inventoryDao;
     private static TransactionProcessorImpl transactionProcessor;
     private static FruitTransaction testTransaction;
 
     @BeforeAll
     static void setUp() {
+        strategy = new HandlerStrategy(new HashMap<>());
         inventoryDao = new InventoryDaoImpl();
         transactionProcessor = new TransactionProcessorImpl(strategy);
         strategy.getStrategyMap().put(OperationType.BALANCE, new BalanceHandler(inventoryDao));
@@ -52,20 +53,17 @@ public void processTransaction_withAllValid_Ok() {
                 () -> {
                     transactionProcessor.processTransaction(testTransaction);
                     assertEquals(100, inventoryDao.getAmountByFruit("potato"));
-
                 },
                 () -> {
                     testTransaction.setOperationType(OperationType.PURCHASE);
                     testTransaction.setQuantity(15);
                     transactionProcessor.processTransaction(testTransaction);
-
                     assertEquals(85, inventoryDao.getAmountByFruit("potato"));
                 },
                 () -> {
                     testTransaction.setOperationType(OperationType.SUPPLY);
                     testTransaction.setQuantity(25);
                     transactionProcessor.processTransaction(testTransaction);
-
                     assertEquals(110, inventoryDao.getAmountByFruit("potato"));
                 },
                 () -> {

src/test/java/core/basesyntax/strategy/HandlerStrategyTest.java

@@ -20,14 +20,13 @@ public class HandlerStrategyTest {
     private static InventoryDao inventoryDao;
     private static final Map<OperationType, OperationHandler> testMap = new HashMap<>();
     private static HandlerStrategy handlerStrategy = new HandlerStrategy(testMap);
-
     private static BalanceHandler balanceHandler;
     private static PurchaseHandler purchaseHandler;
     private static ReturnHandler returnHandler;
     private static SupplyHandler supplyHandler;
 
     @BeforeAll
-    public static void setUP() {
+    public static void setUp() {
         handlerStrategy = new HandlerStrategy(testMap);
         inventoryDao = new InventoryDaoImpl();
         balanceHandler = new BalanceHandler(inventoryDao);
@@ -41,7 +40,7 @@ public static void setUP() {
     }
 
     @Test
-    public void etHandlerByOperationType_validTypes_Ok() {
+    public void getHandlerByOperationType_validTypes_Ok() {
         assertAll(
                 () -> assertEquals(balanceHandler,
                         handlerStrategy.getHandlerByOperationType(OperationType.BALANCE),
@@ -60,7 +59,8 @@ public void etHandlerByOperationType_validTypes_Ok() {
 
     @Test
     public void getHandlerByOperationType_byNullOperationType_NotOk() {
-        assertThrows(RuntimeException.class, () -> handlerStrategy.getHandlerByOperationType(null));
+        assertThrows(RuntimeException.class,
+                () -> handlerStrategy.getHandlerByOperationType(null));
     }
 
     @Test