Added more unit tests and continued refactoring the scanner package

src/scanner/LispScanner.java

@@ -91,7 +91,7 @@ public class LispScanner {
     }
 
     private Token retrieveString(char firstDoubleQuote) throws IOException {
-        StringBuffer text = new StringBuffer();
+        StringBuilder text = new StringBuilder();
         int startLine = lineNumber;
         int startColumn = columnNumber;
         char prevChar = firstDoubleQuote;
@@ -130,7 +130,7 @@ public class LispScanner {
     }
 
     private Token retrieveNumber(char firstDigit) throws IOException {
-        StringBuffer text = new StringBuffer();
+        StringBuilder text = new StringBuilder();
         int startColumn = columnNumber;
 
         text.append(firstDigit);
@@ -164,7 +164,7 @@ public class LispScanner {
     }
 
     private Token retrieveIdentifier(char firstChar) throws IOException {
-        StringBuffer text = new StringBuffer();
+        StringBuilder text = new StringBuilder();
         int startColumn = columnNumber;
 
         text.append(firstChar);

test/scanner/LispFilterInputStreamTester.java

@@ -12,11 +12,33 @@ import testutils.TestUtilities;
 
 public class LispFilterInputStreamTester {
 
-    private StringBuilder stringBuilder;
+    private StringBuilder charactersRead;
 
     @Before
     public void setUp() {
-        stringBuilder = new StringBuilder();
+        charactersRead = new StringBuilder();
+    }
+
+    @Test
+    public void noBytesIn_noBytesOut() throws IOException {
+        String input = "";
+
+        assertEquals(input, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void oneCharacter_notRemoved() throws IOException {
+        String input = "x";
+
+        assertEquals(input, getLispFilterInputStreamResult(input));
+    }
+
+    @Test
+    public void allNonCommentCharacters_notRemoved() throws IOException {
+        String input = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                + "`1234567890-=~!@#$%^&*()_+[]\\',./{}|:\"<>?";
+
+        assertEquals(input, getLispFilterInputStreamResult(input));
     }
 
     @Test
@@ -91,11 +113,11 @@ public class LispFilterInputStreamTester {
         int c = inputStream.read();
 
         while (c != -1) {
-            stringBuilder.append((char) c);
+            charactersRead.append((char) c);
             c = inputStream.read();
         }
 
-        return stringBuilder.toString();
+        return charactersRead.toString();
     }
 
 }

test/scanner/LispScannerLineColumnTester.java

@@ -16,6 +16,14 @@ public class LispScannerLineColumnTester {
     public void setUp() throws Exception {
     }
 
+    @Test
+    public void givenNothing_RecordsCorrectEOFLocation() throws IOException {
+        String input = "";
+        LineColumn[] expectedLinesAndColumns = { LineColumn.create(1, 0) };
+
+        assertTokenLineAndColumnsMatch(input, expectedLinesAndColumns);
+    }
+
     @Test
     public void givenSimpleString_RecordsCorrectLocation() throws IOException {
         String input = "\"string\"";

test/scanner/LispScannerTextTester.java

@@ -0,0 +1,57 @@
+package scanner;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.junit.Test;
+
+import testutils.TestUtilities;
+
+public class LispScannerTextTester {
+
+    @Test
+    public void givenIdentifier_RecordsCorrectText() throws IOException {
+        String input = "identifier";
+
+        assertTokenTextMatches(input, input);
+    }
+
+    @Test
+    public void givenNumber_RecordsCorrectText() throws IOException {
+        String input = "192837456";
+
+        assertTokenTextMatches(input, input);
+    }
+
+    @Test
+    public void givenString_RecordsCorrectText() throws IOException {
+        String input = "\"String!!! \n More... \"";
+
+        assertTokenTextMatches(input, input);
+    }
+
+    @Test
+    public void givenEmptyStream_RecordsCorrectInputStreamName() throws IOException {
+        String input = "";
+        String expectedInputStreamName = "testInputStream";
+
+        assertInputFileNameMatches(input, expectedInputStreamName);
+    }
+
+    private void assertTokenTextMatches(String input, String expectedText) throws IOException {
+        InputStream stringInputStream = TestUtilities.createInputStreamFromString(input);
+        LispScanner lispScanner = new LispScanner(stringInputStream, "stringInputStream");
+
+        assertEquals(expectedText, lispScanner.nextToken().getText());
+    }
+
+    private void assertInputFileNameMatches(String input, String expectedInputFileName) throws IOException {
+        InputStream stringInputStream = TestUtilities.createInputStreamFromString(input);
+        LispScanner lispScanner = new LispScanner(stringInputStream, expectedInputFileName);
+
+        assertEquals(expectedInputFileName, lispScanner.nextToken().getFName());
+    }
+
+}

test/scanner/LispScannerTypeTester.java

@@ -20,6 +20,14 @@ public class LispScannerTypeTester {
         assertTokenTypesMatch(input, expectedTypes);
     }
 
+    @Test(expected = RuntimeException.class)
+    public void givenBadCharacter_ThrowsException() throws IOException {
+        String input = "[";
+        Token.Type[] expectedTypes = {};
+
+        assertTokenTypesMatch(input, expectedTypes);
+    }
+
     @Test
     public void givenNil_returnsCorrectTokenTypes() throws IOException {
         String input = "()";
@@ -60,6 +68,14 @@ public class LispScannerTypeTester {
         assertTokenTypesMatch(input, expectedTypes);
     }
 
+    @Test(expected = RuntimeException.class)
+    public void givenUnterminatedString_ThrowsException() throws IOException {
+        String input = "\"oh no!";
+        Token.Type[] expectedTypes = { Type.STRING };
+
+        assertTokenTypesMatch(input, expectedTypes);
+    }
+
     @Test
     public void givenIdentifier_returnsCorrectTokenTypes() throws IOException {
         String input = "abcdefgHIJKLMNOP1234";
@@ -68,6 +84,22 @@ public class LispScannerTypeTester {
         assertTokenTypesMatch(input, expectedTypes);
     }
 
+    @Test
+    public void givenSingleDigitNumber_returnsCorrectTokenTypes() throws IOException {
+        String input = "1";
+        Token.Type[] expectedTypes = { Type.NUMBER };
+
+        assertTokenTypesMatch(input, expectedTypes);
+    }
+
+    @Test
+    public void givenMultipleDigitNumber_returnsCorrectTokenTypes() throws IOException {
+        String input = "1234567890";
+        Token.Type[] expectedTypes = { Type.NUMBER };
+
+        assertTokenTypesMatch(input, expectedTypes);
+    }
+
     @Test
     public void givenQuote_returnsCorrectTokenTypes() throws IOException {
         String input = "'";