Merge branch 'pretty-printer-string-stripping' into 'dev'

Overzealous Pretty Printer End of Line Stripping

Closes #3678

See merge request monticore/monticore!904

monticore-generator/src/main/resources/_prettyprinter/full/FullPrettyPrintMethod.ftl

@@ -5,4 +5,7 @@
 getPrinter().clearBuffer();
 getTraverser().clearTraversedElements();
 node.accept(getTraverser());
-return getPrinter().getContent().stripTrailing();
+
+// do not overzealous strip trailing linebreaks, only trailing spaces within the last line
+getPrinter().stripTrailing();
+return getPrinter().getContent();

monticore-grammar/src/test/java/de/monticore/statements/prettyprint/TrailingSpacesPrettyPrinterTest.java

@@ -0,0 +1,55 @@
+/* (c) https://github.com/MontiCore/monticore */
+package de.monticore.statements.prettyprint;
+
+import de.monticore.expressions.expressionsbasis._ast.ASTExpression;
+import de.monticore.statements.mccommonstatements._ast.ASTMCJavaBlock;
+import de.monticore.statements.mcvardeclarationstatements._ast.ASTLocalVariableDeclarationStatement;
+import de.monticore.statements.mcvardeclarationstatements._ast.ASTSimpleInit;
+import de.monticore.statements.testmccommonstatements.TestMCCommonStatementsMill;
+import de.monticore.statements.testmccommonstatements._parser.TestMCCommonStatementsParser;
+import de.se_rwth.commons.logging.Log;
+import de.se_rwth.commons.logging.LogStub;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.Optional;
+
+import static org.junit.Assert.*;
+
+public class TrailingSpacesPrettyPrinterTest {
+
+  TestMCCommonStatementsParser parser;
+
+  @Before
+  public void init() {
+    LogStub.init();
+    Log.enableFailQuick(false);
+    TestMCCommonStatementsMill.reset();
+    TestMCCommonStatementsMill.init();
+    parser = TestMCCommonStatementsMill.parser();
+  }
+
+  @Test
+  public void testSingleLineCommentEOL() throws IOException {
+    // Scenario: An expression is string-concatenated into a statement as the initial value
+    // First, we have to extract the inner AST node with the comment
+    Optional<ASTMCJavaBlock> blocks = parser.parse_StringMCJavaBlock("{int i1 = a // single line comment\n; int i2 = b; }");
+    assertFalse(parser.hasErrors());
+    assertTrue(blocks.isPresent());
+    ASTLocalVariableDeclarationStatement setStatement = (ASTLocalVariableDeclarationStatement) blocks.get().getMCBlockStatementList().get(0);
+    ASTExpression initialValueAST = ((ASTSimpleInit) setStatement.getLocalVariableDeclaration().getVariableDeclarator(0).getVariableInit()).getExpression();
+    assertEquals(1, initialValueAST.get_PostCommentList().size());
+
+    // print the initial value expression
+    String initialValue = TestMCCommonStatementsMill.prettyPrint(initialValueAST, true);
+    // and ensure the pretty printed string ends with a linebreak
+    assertTrue(initialValue.endsWith("\n"));
+
+    // then test to parse this value inlined - in case no linebreak is present, this will fail
+    Optional<ASTMCJavaBlock> statement = parser.parse_StringMCJavaBlock("{int i = " + initialValue + "; int i2 = 0; }");
+    assertFalse(parser.hasErrors());
+    assertTrue(statement.isPresent());
+  }
+
+}