Refactored and added unit tests for LispFilterInputStream

src/main/LispInterpreter.java

@@ -21,7 +21,7 @@ import java.text.MessageFormat;
  */
 public class LispInterpreter {
 
-    private static final String GREETING = "SUNY Potsdam Lisp Interpreter - Version 1.0.1";
+    private static final String GREETING = "SUNY Potsdam Lisp Interpreter - Version 4.4.3";
     private static final String PROMPT = "~ ";
 
     public static final String ANSI_RESET = "\u001B[0m";

src/scanner/LispFilterInputStream.java

@@ -5,14 +5,14 @@ import java.io.FilterInputStream;
 import java.io.IOException;
 
 /**
- * Replaces Lisp comments with newlines in an input stream.
+ * Removes Lisp comments from an input stream.
  */
-public class LispFilterStream extends FilterInputStream {
+public class LispFilterInputStream extends FilterInputStream {
 
     private boolean inQuote;
     private int nextCharacter;
 
-    public LispFilterStream(InputStream in) {
+    public LispFilterInputStream(InputStream in) {
         super(in);
         inQuote = false;
         nextCharacter = 0;

src/scanner/LispScanner.java

@@ -18,7 +18,7 @@ import java.io.IOException;
  */
 public class LispScanner {
 
-    private LispFilterStream inStream;
+    private LispFilterInputStream inStream;
     private Token currToken;
     private String fileName;
     private int line;
@@ -35,7 +35,7 @@ public class LispScanner {
      *  the name of the file that <code>in</code> is reading from
      */
     public LispScanner(InputStream in, String fileName) {
-        this.inStream = new LispFilterStream(new BufferedInputStream(in));
+        this.inStream = new LispFilterInputStream(new BufferedInputStream(in));
         this.currToken = null;
         this.fileName = fileName;
         this.line = 1;

test/scanner/LispFilterInputStreamTester.java

@@ -0,0 +1,85 @@
+package scanner;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class LispFilterInputStreamTester {
+
+    @Test
+    public void oneComment_Removed() throws IOException {
+        String input = ";comment";
+        String expectedResult = "";
+        assertEquals(expectedResult, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void multipleComments_Removed() throws IOException {
+        String input = ";comment1\n;comment2\n;comment3";
+        String expectedResult = "\n\n";
+        assertEquals(expectedResult, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void nil_NotRemoved() throws IOException {
+        String input = "()";
+        String expectedResult = "()";
+        assertEquals(expectedResult, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void interiorComment_Removed() throws IOException {
+        String input = "(;this is a comment\n)";
+        String expectedResult = "(\n)";
+        assertEquals(expectedResult, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void commentInString_NotRemoved() throws IOException {
+        String input = "\"string;this should remain\"";
+        assertEquals(input, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void commentInStringWithNewline_NotRemoved() throws IOException {
+        String input = "\"string;this should\n remain\"";
+        assertEquals(input, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void manyCommentsWithStatements_OnlyCommentsRemoved() throws IOException {
+        String input = ";first comment \n '(1 2 3) \n ;second comment \n (defun add1 (x) (+ x 1)) ;third comment";
+        String expectedResult = "\n '(1 2 3) \n \n (defun add1 (x) (+ x 1)) ";
+        assertEquals(expectedResult, getLispFilterInputStreamResult(input));
+    }
+
+    private String getLispFilterInputStreamResult(String inputString) throws IOException {
+        InputStream stringInputStream = createInputStreamFromString(inputString);
+        LispFilterInputStream lispFilterInputStream = new LispFilterInputStream(stringInputStream);
+
+        return readInputStreamIntoString(lispFilterInputStream);
+    }
+
+    private InputStream createInputStreamFromString(String string) {
+        return new ByteArrayInputStream(string.getBytes());
+    }
+
+    private String readInputStreamIntoString(InputStream inputStream) throws IOException {
+        StringBuilder stringBuilder = new StringBuilder();
+        int c = inputStream.read();
+
+        while (c != -1) {
+            stringBuilder.append((char) c);
+            c = inputStream.read();
+        }
+
+        return stringBuilder.toString();
+    }
+
+}

test/scanner/LispFilterStreamTester.java

@@ -1,22 +0,0 @@
-package scanner;
-
-import static org.junit.Assert.*;
-
-import org.junit.Before;
-import org.junit.Test;
-
-public class LispFilterStreamTester {
-
-    private LispFilterStream lispFilterStream;
-
-    @Before
-    public void setUp() throws Exception {
-        lispFilterStream = new LispFilterStream(null);
-    }
-
-    @Test
-    public void testRead() {
-        fail("Not yet implemented");
-    }
-
-}