fixup! Handle CR without NL printed in EditorConsole

Author: matthijskooijman

Diff for: app/src/processing/app/EditorConsole.java

@@ -39,8 +39,8 @@ public class EditorConsole extends JScrollPane {
 
   private static ConsoleOutputStream out;
   private static ConsoleOutputStream err;
-  private static int startOfLine = 0;
-  private static int insertPosition = 0;
+  private int startOfLine = 0;
+  private int insertPosition = 0;
 
   private static synchronized void init(SimpleAttributeSet outStyle, PrintStream outStream, SimpleAttributeSet errStyle, PrintStream errStream) {
     if (out != null) {
@@ -185,21 +185,25 @@ public boolean isEmpty() {
     return document.getLength() == 0;
   }
 
+  // Regex for linesplitting, see insertString for comments.
+  private static final Pattern newLinePattern = Pattern.compile("([^\r\n]*)([\r\n]*\n)?(\r+)?");
+
   public void insertString(String str, SimpleAttributeSet attributes) throws BadLocationException {
     // Separate the string into content, newlines and lone carriage
     // returns.
     //
-    // Doing so allows lone CRs to return the insertPosition to the
+    // Doing so allows lone CRs to move the insertPosition back to the
     // start of the line to allow overwriting the most recent line (e.g.
     // for a progress bar). Any CR or NL that are immediately followed
     // by another NL are bunched together for efficiency, since these
     // can just be inserted into the document directly and still be
     // correct.
     //
-    // This regex is written so it will necessarily match any string
+    // The regex is written so it will necessarily match any string
     // completely if applied repeatedly. This is important because any
     // part not matched would be silently dropped.
-    Matcher m = Pattern.compile("([^\r\n]*)([\r\n]*\n)?(\r+)?").matcher(str);
+    Matcher m = newLinePattern.matcher(str);
+
     while (m.find()) {
       String content = m.group(1);
       String newlines = m.group(2);

Diff for: app/test/processing/app/EditorConsoleTest.java

@@ -0,0 +1,159 @@
+/*
+ * This file is part of Arduino.
+ *
+ * Copyright 2020 Arduino LLC (http://www.arduino.cc/)
+ *
+ * Arduino is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ */
+
+package processing.app;
+
+import java.io.File;
+import javax.swing.SwingUtilities;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class EditorConsoleTest extends AbstractWithPreferencesTest {
+  EditorConsole console;
+
+  @Before
+  public void createConsole() {
+    console = new EditorConsole(null);
+  }
+
+  public String escapeString(String input) {
+    // This escapes backslashes, newlines and carriage returns, to get
+    // more readable assertion failures.
+    return input.replace("\\", "\\\\").replace("\n", "\\n").replace("\r", "\\r");
+  }
+
+  public void assertOutput(String output) {
+    assertEquals(escapeString(output), escapeString(console.getText()));
+  }
+
+  @Test
+  public void testHelloWorld() throws Exception {
+    console.insertString("Hello, world!", null);
+
+    assertOutput("Hello, world!");
+  }
+
+  @Test
+  public void testCrNlHandling() throws Exception {
+    // Do some basic tests with \r\n
+    console.insertString("abc\r\ndef", null);
+    assertOutput("abc\r\ndef");
+
+    console.insertString("xyz", null);
+    assertOutput("abc\r\ndefxyz");
+
+    console.insertString("000\r\n123", null);
+    assertOutput("abc\r\ndefxyz000\r\n123");
+
+    console.insertString("\r\n", null);
+    assertOutput("abc\r\ndefxyz000\r\n123\r\n");
+  }
+
+  @Test
+  public void testNlHandling() throws Exception {
+    // Basic tests, but with just \n
+    console.insertString("abc\ndef", null);
+    assertOutput("abc\ndef");
+
+    console.insertString("xyz", null);
+    assertOutput("abc\ndefxyz");
+
+    console.insertString("000\n123", null);
+    assertOutput("abc\ndefxyz000\n123");
+
+    console.insertString("\n", null);
+    assertOutput("abc\ndefxyz000\n123\n");
+  }
+
+  @Test
+  public void testCrHandling() throws Exception {
+    // Then test that single \r clears the current line
+    console.clear();
+    console.insertString("abc\rdef", null);
+    assertOutput("def");
+
+    // A single \r at the end is not added to the document
+    console.insertString("\r", null);
+    assertOutput("def");
+
+    // Nor are multiple \r at the end
+    console.insertString("\r\r\r", null);
+    assertOutput("def");
+
+    // But it does clear the line on the next write
+    console.insertString("123", null);
+    assertOutput("123");
+
+    // Same when combined with some data
+    console.insertString("\r456\r\r", null);
+    assertOutput("456");
+
+    console.insertString("000", null);
+    assertOutput("000");
+
+    // Then add a newline so preceding data is kept
+    console.insertString("\r\nxxx\r", null);
+    assertOutput("000\r\nxxx");
+
+    // But data after the newline is removed
+    console.insertString("yyy", null);
+    assertOutput("000\r\nyyy");
+
+    // When a \r\n is split across inserts, it becomes a lone \n
+    console.insertString("\r", null);
+    assertOutput("000\r\nyyy");
+    console.insertString("\n", null);
+    assertOutput("000\r\nyyy\n");
+  }
+
+  @Test
+  public void testCrPartialOverwrite() throws Exception {
+    console.insertString("abcdef\r", null);
+    assertOutput("abcdef");
+
+    console.insertString("123", null);
+    assertOutput("123def");
+
+    console.insertString("4", null);
+    assertOutput("1234ef");
+
+    console.insertString("\r\n56", null);
+    assertOutput("1234ef\r\n56");
+  }
+
+  @Test
+  public void testTogether() throws Exception {
+    console.insertString("abc\n123456\rdef\rx\r\nyyy\nzzz\r999", null);
+    assertOutput("abc\nxef456\r\nyyy\n999");
+  }
+}