Implemented CharSequenceReader.ready (#122)

Author: robtimus

src/main/java/org/apache/commons/io/input/CharSequenceReader.java

@@ -165,6 +165,16 @@ public void close() {
         mark = start;
     }
 
+    /**
+     * Tells whether this stream is ready to be read.
+     *
+     * @return {@code true} if more characters from the character sequence are available, or {@code false} otherwise.
+     */
+    @Override
+    public boolean ready() {
+        return idx < end();
+    }
+
     /**
      * Mark the current position.
      *

src/test/java/org/apache/commons/io/input/CharSequenceReaderTest.java

@@ -17,6 +17,7 @@
 package org.apache.commons.io.input;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -51,6 +52,43 @@ public void testClose() throws IOException {
         checkRead(subReader, "Foo");
     }
 
+    @Test
+    public void testReady() throws IOException {
+        final Reader reader = new CharSequenceReader("FooBar");
+        assertTrue(reader.ready());
+        reader.skip(3);
+        assertTrue(reader.ready());
+        checkRead(reader, "Bar");
+        assertFalse(reader.ready());
+        reader.reset();
+        assertTrue(reader.ready());
+        reader.skip(2);
+        assertTrue(reader.ready());
+        reader.skip(10);
+        assertFalse(reader.ready());
+        reader.close();
+        assertTrue(reader.ready());
+        reader.skip(20);
+        assertFalse(reader.ready());
+
+        final Reader subReader = new CharSequenceReader("xFooBarx", 1, 7);
+        assertTrue(subReader.ready());
+        subReader.skip(3);
+        assertTrue(subReader.ready());
+        checkRead(subReader, "Bar");
+        assertFalse(subReader.ready());
+        subReader.reset();
+        assertTrue(subReader.ready());
+        subReader.skip(2);
+        assertTrue(subReader.ready());
+        subReader.skip(10);
+        assertFalse(subReader.ready());
+        subReader.close();
+        assertTrue(subReader.ready());
+        subReader.skip(20);
+        assertFalse(subReader.ready());
+    }
+
     @Test
     public void testMarkSupported() throws Exception {
         try (final Reader reader = new CharSequenceReader("FooBar")) {