Move trimBlankLines

pmd-core/src/main/java/net/sourceforge/pmd/lang/document/Chars.java

@@ -295,6 +295,43 @@ public final class Chars implements CharSequence {
         return trimStart().trimEnd();
     }
 
+    /**
+     * Remove trailing and leading blank lines. The resulting string
+     * does not end with a line terminator.
+     */
+    public Chars trimBlankLines() {
+        int offsetOfFirstNonBlankChar = length();
+        for (int i = 0; i < length(); i++) {
+            if (!Character.isWhitespace(charAt(i))) {
+                offsetOfFirstNonBlankChar = i;
+                break;
+            }
+        }
+        int offsetOfLastNonBlankChar = 0;
+        for (int i = length() - 1; i > offsetOfFirstNonBlankChar; i--) {
+            if (!Character.isWhitespace(charAt(i))) {
+                offsetOfLastNonBlankChar = i;
+                break;
+            }
+        }
+
+        // look backwards before the first non-blank char
+        int cutFromInclusive = lastIndexOf('\n', offsetOfFirstNonBlankChar);
+        // If firstNonBlankLineStart == -1, ie we're on the first line,
+        // we want to start at zero: then we add 1 to get 0
+        // If firstNonBlankLineStart >= 0, then it's the index of the
+        // \n, we want to cut right after that, so we add 1.
+        cutFromInclusive += 1;
+
+        // look forwards after the last non-blank char
+        int cutUntilExclusive = indexOf('\n', offsetOfLastNonBlankChar);
+        if (cutUntilExclusive == StringUtils.INDEX_NOT_FOUND) {
+            cutUntilExclusive = length();
+        }
+
+        return subSequence(cutFromInclusive, cutUntilExclusive);
+    }
+
     /**
      * Remove the suffix if it is present, otherwise returns this.
      */

pmd-core/src/main/java/net/sourceforge/pmd/util/StringUtil.java

@@ -381,42 +381,6 @@ public final class StringUtil {
         }
     }
 
-    /**
-     * Remove trailing and leading blank lines.
-     */
-    public static Chars trimBlankLines(Chars string) {
-        int offsetOfFirstNonBlankChar = string.length();
-        for (int i = 0; i < string.length(); i++) {
-            if (!Character.isWhitespace(string.charAt(i))) {
-                offsetOfFirstNonBlankChar = i;
-                break;
-            }
-        }
-        int offsetOfLastNonBlankChar = 0;
-        for (int i = string.length() - 1; i > offsetOfFirstNonBlankChar; i--) {
-            if (!Character.isWhitespace(string.charAt(i))) {
-                offsetOfLastNonBlankChar = i;
-                break;
-            }
-        }
-
-        // look backwards before the first non-blank char
-        int cutFromInclusive = string.lastIndexOf('\n', offsetOfFirstNonBlankChar);
-        // If firstNonBlankLineStart == -1, ie we're on the first line,
-        // we want to start at zero: then we add 1 to get 0
-        // If firstNonBlankLineStart >= 0, then it's the index of the
-        // \n, we want to cut right after that, so we add 1.
-        cutFromInclusive += 1;
-
-        // look forwards after the last non-blank char
-        int cutUntilExclusive = string.indexOf('\n', offsetOfLastNonBlankChar);
-        if (cutUntilExclusive == StringUtils.INDEX_NOT_FOUND) {
-            cutUntilExclusive = string.length();
-        }
-
-        return string.subSequence(cutFromInclusive, cutUntilExclusive);
-    }
-
 
     private static int countLeadingWhitespace(CharSequence s) {
         int count = 0;

pmd-core/src/test/java/net/sourceforge/pmd/lang/document/CharsTest.java

@@ -310,4 +310,17 @@ public class CharsTest {
         assertThrows(IndexOutOfBoundsException.class, () -> chars.substring(0, 6));
     }
 
+
+    @Test
+    public void testTrimBlankLines() {
+        assertTrimBlankLinesEquals(" \n \n abc \n \n de \n \n ",
+                                   " abc \n \n de ");
+        assertTrimBlankLinesEquals("", "");
+    }
+
+    private void assertTrimBlankLinesEquals(String input, String expected) {
+        Chars actual = Chars.wrap(input).trimBlankLines();
+        assertEquals(Chars.wrap(expected), actual);
+    }
+
 }

pmd-core/src/test/java/net/sourceforge/pmd/util/StringUtilTest.java

@@ -115,20 +115,6 @@ public class StringUtilTest {
         assertEquals("abc", StringUtil.substringAfterLast("abc", '.'));
     }
 
-    @Test
-    public void trimBlankLines() {
-        assertTrimBlankLinesEquals(" \n \n abc \n \n de \n \n ",
-                                   " abc \n \n de ");
-        assertTrimBlankLinesEquals("", "");
-    }
-
-    private void assertTrimBlankLinesEquals(String input, String output) {
-        assertEquals(
-            Chars.wrap(output),
-            StringUtil.trimBlankLines(Chars.wrap(input))
-        );
-    }
-
     @Test
     public void linesWithTrimIndent() {
     }

pmd-test/src/main/java/net/sourceforge/pmd/testframework/RuleTst.java

@@ -50,7 +50,6 @@ import net.sourceforge.pmd.processor.AbstractPMDProcessor;
 import net.sourceforge.pmd.properties.PropertyDescriptor;
 import net.sourceforge.pmd.renderers.TextRenderer;
 import net.sourceforge.pmd.reporting.GlobalAnalysisListener;
-import net.sourceforge.pmd.util.StringUtil;
 
 /**
  * Advanced methods for test cases
@@ -486,7 +485,7 @@ public abstract class RuleTst {
                     throw new RuntimeException("No matching code fragment found for coderef");
                 }
             }
-            code = StringUtil.trimBlankLines(Chars.wrap(code)).toString();
+            code = Chars.wrap(code).trimBlankLines().toString();
 
             String description = getNodeValue(testCode, "description", true);
             int expectedProblems = Integer.parseInt(getNodeValue(testCode, "expected-problems", true).trim());