BAEL-4960: Test for conversion

core-java-modules/core-java-string-conversions-2/src/test/java/com/baeldung/stringtobybiginteger/StringToBigIntegerUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.stringtobybiginteger;
+
+import static org.junit.Assert.assertEquals;
+
+import java.math.BigInteger;
+
+import org.junit.Test;
+
+public class StringToBigIntegerUnitTest {
+	
+	@Test
+	public void whenGetStringWithOutRadix_thenOK() {
+		final String inputString = "878";
+		BigInteger result = new BigInteger(inputString);
+		assertEquals("878", result.toString());
+	}
+
+	@Test
+	public void whenGetStringWithRadix_thenOK() {
+		final String inputString = "290f98";
+		BigInteger result = new BigInteger(inputString, 16);
+		assertEquals("2690968", result.toString());
+	}
+
+	@Test(expected = NumberFormatException.class)
+	public void whenGetStringWithOutRadix_thenThrowError() {
+		final String inputString = "290f98";
+		new BigInteger(inputString);
+	}
+
+	@Test(expected = NumberFormatException.class)
+	public void whenGetStringWithRadix_thenThrowError() {
+		final String inputString = "Hello Baeldung";
+		new BigInteger(inputString, 7);
+	}
+
+	@Test
+	public void whenGetStringUsingByte_thenOk() {
+		final String inputString = "Hello Baeldung";
+		byte[] inputStringBytes = inputString.getBytes();
+		BigInteger result = new BigInteger(inputStringBytes);
+		assertEquals("Hello Baeldung", new String(result.toByteArray()));
+	}
+}