fix code

hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java

@@ -47,5 +47,22 @@ public class CharSequenceUtilTest {
 		Assert.assertEquals(str1, str2);
 	}
 
-	// ------------------------------------------------------------------------ remove
+	@Test
+	public void indexOfTest(){
+		int index = CharSequenceUtil.indexOf("abc123", '1');
+		Assert.assertEquals(3, index);
+		index = CharSequenceUtil.indexOf("abc123", '3');
+		Assert.assertEquals(5, index);
+		index = CharSequenceUtil.indexOf("abc123", 'a');
+		Assert.assertEquals(0, index);
+	}
+
+	@Test
+	public void indexOfTest2(){
+		int index = CharSequenceUtil.indexOf("abc123", '1', 0, 3);
+		Assert.assertEquals(-1, index);
+
+		index = CharSequenceUtil.indexOf("abc123", 'b', 0, 3);
+		Assert.assertEquals(1, index);
+	}
 }

hutool-core/src/test/java/cn/hutool/core/text/finder/CharFinderTest.java

@@ -0,0 +1,30 @@
+package cn.hutool.core.text.finder;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class CharFinderTest {
+
+	@Test
+	public void startTest(){
+		int start = new CharFinder('a').setText("cba123").start(2);
+		Assert.assertEquals(2, start);
+
+		start = new CharFinder('c').setText("cba123").start(2);
+		Assert.assertEquals(-1, start);
+
+		start = new CharFinder('3').setText("cba123").start(2);
+		Assert.assertEquals(5, start);
+	}
+	@Test
+	public void negativeStartTest(){
+		int start = new CharFinder('a').setText("cba123").setNegative(true).start(2);
+		Assert.assertEquals(2, start);
+
+		start = new CharFinder('2').setText("cba123").setNegative(true).start(2);
+		Assert.assertEquals(-1, start);
+
+		start = new CharFinder('c').setText("cba123").setNegative(true).start(2);
+		Assert.assertEquals(0, start);
+	}
+}