BAEL-3143 - nextLine() method of java.util.Scanner class

vatsalgosar · vatsalgosar · commit 9946fa53a1e7 · 2019-10-21T00:17:18.000+05:30
diff --git a/core-java-modules/core-java-io-2/src/test/java/com/baeldung/scanner/JavaScannerUnitTest.java b/core-java-modules/core-java-io-2/src/test/java/com/baeldung/scanner/JavaScannerUnitTest.java
@@ -0,0 +1,54 @@
+package com.baeldung.scanner;
+
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.NoSuchElementException;
+import java.util.Scanner;
+
+import static org.assertj.core.api.Assertions.fail;
+import static org.junit.Assert.assertEquals;
+
+public class JavaScannerUnitTest {
+
+    @Test
+    public void whenReadingLines_thenCorrect() {
+        String input = "Scanner\nTest\n";
+
+        byte[] byteArray = input.getBytes(StandardCharsets.UTF_8);
+        //@formatter:off
+        try (InputStream is = new ByteArrayInputStream(byteArray);
+             Scanner scanner = new Scanner(is)) {
+
+            //@formatter:on
+            String result = scanner.nextLine() + " " + scanner.nextLine();
+
+            String expected = input.replace("\n", " ")
+                    .trim();
+            assertEquals(expected, result);
+        } catch (IOException e) {
+            fail(e.getMessage());
+        }
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void whenReadingLinesFromStringContainingNoLines_thenThrowNoSuchElementException() {
+        String input = "";
+        Scanner scanner = new Scanner(input);
+        String result = scanner.nextLine();
+        scanner.close();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void whenReadingLinesUsingClosedScanner_thenThrowIllegalStateException() {
+        String input = "";
+        Scanner scanner = new Scanner(input);
+        scanner.close();
+        String result = scanner.nextLine();
+    }
+
+
+}
