fix: corrected errors in exceptions and tests

app/src/main/java/ru/project/io/StudentCsvReader.java

@@ -14,26 +14,22 @@ import org.apache.commons.csv.CSVParser;
 import org.apache.commons.csv.CSVRecord;
 import ru.project.student.Student;
 import ru.project.student.StudentBuilder;
-
+  public class StudentCsvReader implements Iterator<Student> {
-public class StudentCsvReader implements Iterator<Student> {
   private static final String GROUP_NUMBER = "groupNumber";
   private static final String AVERAGE_GRADE = "averageGrade";
   private static final String RECORD_BOOK_NUMBER = "recordBookNumber";
-
   private final CSVParser parser;
   private final Iterator<CSVRecord> records;
-
+  private int lineOfFile=0;
-  private int lineOfFile;
+    public StudentCsvReader(Path path) {
-
-  public StudentCsvReader(Path path2) {
-    lineOfFile = 0;
-    Path path = Paths.get(path2);
       if (!path.isAbsolute()) {
         throw new IllegalArgumentException("File path must be absolute");
       }
-
       try {
-      CSVFormat format = CSVFormat.DEFAULT.builder().setHeader().setSkipHeaderRecord(true).get();
+        CSVFormat format = CSVFormat.DEFAULT.builder()
+                .setHeader()
+                .setSkipHeaderRecord(true)
+                .build();
         this.parser = CSVParser.parse(path, StandardCharsets.UTF_8, format);
         validateHeader(parser.getHeaderMap());
         this.records = parser.iterator();
@@ -41,38 +37,48 @@ public class StudentCsvReader implements Iterator<Student> {
         throw new UncheckedIOException(e);
       }
     }
-
     @Override
     public boolean hasNext() {
       return records.hasNext();
     }
-
     @Override
     public Student next() {
-    lineOfFile++;
       if (!records.hasNext()) {
-      throw new NoSuchElementException("Problem at line " + lineOfFile + ".");
+        throw new NoSuchElementException("No more records at line " + (lineOfFile + 1));
       }
-
+      lineOfFile++;
       CSVRecord record = records.next();
       if (record.size() != 3) {
         throw new IllegalArgumentException(
-          "Problem at line " + lineOfFile + ".Expected 3 columns, but got " + record.size());
+                "Problem at line " + lineOfFile + ". Expected 3 columns, but got " + record.size());
+      }
+      String groupNumber = record.get(GROUP_NUMBER);
+      String averageGradeStr = record.get(AVERAGE_GRADE);
+      String recordBookNumberStr = record.get(RECORD_BOOK_NUMBER);
+      double averageGrade;
+      int recordBookNumber;
+      try {
+        averageGrade = Double.parseDouble(averageGradeStr);
+      } catch (NumberFormatException e) {
+        throw new IllegalArgumentException(
+                "Problem at line " + lineOfFile + ": cannot parse averageGrade '" + averageGradeStr + "' as double", e);
       }
       try {
-      double averageGrade = Double.parseDouble(record.get(AVERAGE_GRADE));
+        recordBookNumber = Integer.parseInt(recordBookNumberStr);
-      int recordBookNumber = Integer.parseInt(record.get(RECORD_BOOK_NUMBER));
+      } catch (NumberFormatException e) {
+        throw new IllegalArgumentException(
+                "Problem at line " + lineOfFile + ": cannot parse recordBookNumber '" + recordBookNumberStr + "' as int", e);
+      }
       return new StudentBuilder()
-          .setGroupNumber(record.get(GROUP_NUMBER))
+              .setGroupNumber(groupNumber)
               .setAverageGrade(averageGrade)
               .setRecordBookNumber(recordBookNumber)
               .build();
-    } catch (NumberFormatException e) {
-      throw new IllegalArgumentException(
-          "Problem at line " + lineOfFile + ". Unacceptable type convertation");
     }
+    @Override
+    public void close() throws IOException {
+      parser.close();
     }
-
     private static void validateHeader(Map<String, Integer> headerMap) {
       String[] expected = {GROUP_NUMBER, AVERAGE_GRADE, RECORD_BOOK_NUMBER};
       if (headerMap.size() != expected.length
@@ -80,4 +86,4 @@ public class StudentCsvReader implements Iterator<Student> {
         throw new IllegalArgumentException("Invalid CSV header");
       }
     }
-}
+  }

app/src/test/java/ru/project/io/StudentCsvReaderTest.java

@@ -1,10 +1,8 @@
 package ru.project.io;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import java.io.UncheckedIOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
@@ -15,167 +13,104 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 import ru.project.student.Student;
-
+import ru.project.collection.MyLinkedList;
+import ru.project.collection.MyList;
+import ru.project.collectors.MyCollectors;
+import ru.project.collectors.MyListCollector;
 class StudentCsvReaderTest {
-  @TempDir Path tempDir;
+    @TempDir
-  private Path studentPath;
+    Path tempDir;
-
-  // Testing StudentCsvReader
-
-  @BeforeAll
-  void generateStudentTestFile() {
-    studentPath = tempDir.resolve("students.csv");
-    Files.write(
-        studentPath,
-        new String[] {"groupNumber,averageGrade,recordBookNumber", "A21,5.0,331", "A21,4.0,332"},
-        StandardCharsets.UTF_8);
-  }
-
-  @BeforeEach
-  void setUp() {
-    valideReader = new StudentCsvReader(studentPath.toAbsolutePath().toString());
-  }
-
     @Test
-  void readerTestRejectRelativePath() {
+    void shouldTestreadValidCsvIntoMyList() throws IOException {
-    assertThrows(
+        Path csv = tempDir.resolve("students.csv");
-        IllegalArgumentException.class, () -> new StudentCsvReader(studentPath.toString()));
+        String content = String.join("\n",
+                "groupNumber,averageGrade,recordBookNumber",
+                "M10,4.5,12345",   // валидно: 1 буква + 2 цифры
+                "B05,3.8,12346"    // валидно
+        );
+        Files.writeString(csv, content, StandardCharsets.UTF_8);
+        try (var reader = new StudentCsvReader(csv.toAbsolutePath())) {
+            var studentStream = StreamSupport.stream(
+                    Spliterators.spliteratorUnknownSize(reader, 0),
+                    false
+            );
+            MyList<Student> students = studentStream
+                    .collect(MyCollectors.toMyList());
+            assertEquals(2, students.size());
+            assertEquals("M10", students.get(0).getGroupNumber());
+            assertEquals(4.5, students.get(0).getAverageGrade(), 0.0);
+            assertEquals(12345, students.get(0).getRecordBookNumber());
+            assertEquals("B05", students.get(1).getGroupNumber());
+            assertEquals(3.8, students.get(1).getAverageGrade(), 0.0);
+            assertEquals(12346, students.get(1).getRecordBookNumber());
         }
-
-  @Test
-  void readerRejectPathIsDir() {
-    assertThrows(UncheckedIOException.class, () -> new StudentCsvReader(tempDir.toAbsolutePath()));
     }
-
     @Test
-  void readerTestFileNotExist() {
+    void shouldTestinvalidHeaderThrowsException() throws IOException {
-    assertThrows(
+        Path csv = tempDir.resolve("bad-header.csv");
-        UncheckedIOException.class,
+        String content = """
-        () -> new StudentCsvReader(tempDir.resolve("sss.csv").toAbsolutePath().toString()));
+                badGroup,badGrade,badBook
-  }
+                M101,4.5,12345
-
+                """;
-  @Test
+        Files.writeString(csv, content, StandardCharsets.UTF_8);
-  void testSkipsHeader() {
+        IllegalArgumentException ex = assertThrows(
-    Student student = valideReader.next();
-    assertNotEquals(student.getGroupNumber(), "groupNumber");
-  }
-
-  @Test
-  void testCreationStudentOnValidData() {
-    Student student = valideReader.next();
-    assertEquals(student.getGroupNumber(), "A21");
-    assertEquals(student.getAverageGrade(), 5.0);
-    assertEquals(student.getRecordBookNumber(), 331);
-  }
-
-  @Test
-  void testNotSkippingFirstStudent() {
-    valideReader.hasNext();
-    valideReader.hasNext();
-    Student student = valideReader.next();
-    assertEquals(student.getGroupNumber(), "A21");
-    assertEquals(student.getAverageGrade(), 5.0);
-    assertEquals(student.getRecordBookNumber(), 331);
-  }
-
-  @Test
-  void testValidEndsOfFile() {
-    valideReader.next();
-    valideReader.next();
-    assertTrue(!valideReader.hasNext());
-  }
-
-  @Test
-  void testOutOfIndex() {
-    assertThrows(
-        NoSuchElementException.class,
-        () -> {
-          Student student = valideReader.next();
-          student = valideReader.next();
-          student = valideReader.next();
-        });
-  }
-
-  @Test
-  void readerTestRejectFewParametres() {
-    assertThrows(
                 IllegalArgumentException.class,
-        () -> {
+                () -> new StudentCsvReader(csv.toAbsolutePath())
-          Path path = tempDir.resolve("fewparameters.csv");
+        );
-          Files.write(
+        assertTrue(ex.getMessage().contains("Invalid CSV header"));
-              path,
-              new String[] {"groupNumber,averageGrade,recordBookNumber", "A21,5.0"},
-              StandardCharsets.UTF_8);
-          StudentCsvReader reader = new StudentCsvReader(path.toAbsolutePath().toString());
-          Student student = reader.next();
-        });
     }
-
     @Test
-  void readerTestRejectInvalidGroupNumber() {
+    void shouldTestwrongColumnCountThrowsException() throws IOException {
-    assertThrows(
+        Path csv = tempDir.resolve("wrong-columns.csv");
+        String content = """
+                groupNumber,averageGrade,recordBookNumber
+                M101,4.5
+                """;
+        Files.writeString(csv, content, StandardCharsets.UTF_8);
+        var reader = new StudentCsvReader(csv.toAbsolutePath());
+        assertTrue(reader.hasNext());
+        // следующая строка имеет только 2 колонки
+        IllegalArgumentException ex = assertThrows(
                 IllegalArgumentException.class,
-        () -> {
+                reader::next
-          Path path = tempDir.resolve("invalid_groupnumber.csv");
+        );
-          Files.write(
+        assertTrue(ex.getMessage().contains("Expected 3 columns"));
-              path,
-              new String[] {
-                "groupNumber,averageGrade,recordBookNumber", "AAA,5.0,331", "A21,4.0,332"
-              },
-              StandardCharsets.UTF_8);
-          StudentCsvReader reader = new StudentCsvReader(path.toAbsolutePath().toString());
-          Student student = reader.next();
-        });
     }
-
     @Test
-  void readerTestRejectInvalidAverageGrade() {
+    void shouldTestparseErrorThrowsExceptionWithDetails() throws IOException {
-    assertThrows(
+        Path csv = tempDir.resolve("parse-error.csv");
+        String content = """
+                groupNumber,averageGrade,recordBookNumber
+                M101,not-a-number,12345
+                """;
+        Files.writeString(csv, content, StandardCharsets.UTF_8);
+
+        var reader = new StudentCsvReader(csv.toAbsolutePath());
+        assertTrue(reader.hasNext());
+        IllegalArgumentException ex = assertThrows(
                 IllegalArgumentException.class,
-        () -> {
+                reader::next
-          Path path = tempDir.resolve("invalid_averagegrade.csv");
+        );
-          Files.write(
+        assertTrue(ex.getMessage().contains("cannot parse averageGrade"));
-              path,
-              new String[] {
-                "groupNumber,averageGrade,recordBookNumber", "A21,-5.0,331", "A21,4.0,332"
-              },
-              StandardCharsets.UTF_8);
-          StudentCsvReader reader = new StudentCsvReader(path.toAbsolutePath().toString());
-          Student student = reader.next();
-        });
     }
-
     @Test
-  void readerTestRejectInvalidRecordBookNumber() {
+    void shouldTestemptyDataAfterHeaderThrowsNoSuchElement() throws IOException {
-    assertThrows(
+        Path csv = tempDir.resolve("empty-data.csv");
-        IllegalArgumentException.class,
+        String content = """
-        () -> {
+                groupNumber,averageGrade,recordBookNumber
-          Path path = tempDir.resolve("invalid_recordbooknumber.csv");
+                """;
-          Files.write(
+        Files.writeString(csv, content, StandardCharsets.UTF_8);
-              path,
+        var reader = new StudentCsvReader(csv.toAbsolutePath());
-              new String[] {
+        assertFalse(reader.hasNext());
-                "groupNumber,averageGrade,recordBookNumber", "A21,5.0,-331", "A21,4.0,332"
+        assertThrows(NoSuchElementException.class, reader::next);
-              },
-              StandardCharsets.UTF_8);
-          StudentCsvReader reader = new StudentCsvReader(path.toAbsolutePath().toString());
-          Student student = reader.next();
-        });
     }
-
     @Test
-  void testInvalidHeader() {
+    void shouldTestrelativePathThrowsException() {
-    assertThrows(
+        Path relative = Path.of("relative-path.csv");
+        IllegalArgumentException ex = assertThrows(
                 IllegalArgumentException.class,
-        () -> {
+                () -> new StudentCsvReader(relative)
-          Path path = tempDir.resolve("invalid_header.csv");
+        );
-          Files.write(
+        assertTrue(ex.getMessage().contains("absolute"));
-              path,
-              new String[] {
-                "groupNumber,averageGrade,recordBookNomber", "A21,5.0,-331", "A21,4.0,332"
-              },
-              StandardCharsets.UTF_8);
-          StudentCsvReader reader = new StudentCsvReader(path.toAbsolutePath().toString());
-          Student student = reader.next();
-        });
     }
 }