https://github.com/petitparser/java-petitparser/issues/80

Author: renggli

petitparser-core/src/test/java/org/petitparser/Assertions.java

@@ -6,23 +6,35 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 public class Assertions {
 
+  public static void assertAccept(Parser parser, String input) {
+    assertAccept(parser, input, input.length());
+  }
+
+  public static void assertAccept(Parser parser, String input, int position) {
+    Result result = parser.parse(input);
+    String resultToString = result.toString();
+    assertTrue("Expected parse success, but got " + resultToString, result.isSuccess());
+    assertEquals("Position", position, result.getPosition());
+    assertNull("No message expected", result.getMessage());
+    assertEquals("Fast parse", position, parser.fastParseOn(input, 0));
+    assertTrue("Accept", parser.accept(input));
+  }
+
   public static <T> void assertSuccess(Parser parser, String input, T result) {
     assertSuccess(parser, input, result, input.length());
   }
 
   public static <T> void assertSuccess(
       Parser parser, String input, T expected, int position) {
     Result result = parser.parse(input);
-    assertNotNull(result.toString());
-    assertTrue("Expected parse success", result.isSuccess());
-    assertFalse("Expected parse success", result.isFailure());
+    String resultToString = result.toString();
+    assertTrue("Expected parse success, but got " + resultToString, result.isSuccess());
     assertEquals("Position", position, result.getPosition());
     assertEquals("Result", expected, result.get());
     assertNull("No message expected", result.getMessage());
@@ -47,9 +59,8 @@ public static <T> void assertFailure(
   public static <T> void assertFailure(
       Parser parser, String input, int position, String message) {
     Result result = parser.parse(input);
-    assertNotNull(result.toString());
-    assertFalse("Expected parse failure", result.isSuccess());
-    assertTrue("Expected parse failure", result.isFailure());
+    String resultToString = result.toString();
+    assertTrue("Expected parse failure, but got " + resultToString, result.isFailure());
     assertEquals("Position", position, result.getPosition());
     if (message != null) {
       assertEquals("Message expected", message, result.getMessage());

petitparser-core/src/test/java/org/petitparser/RegressionsTest.java

@@ -1,8 +1,13 @@
 package org.petitparser;
 
 import org.junit.Test;
+import org.petitparser.context.Token;
 import org.petitparser.parser.Parser;
+import org.petitparser.parser.primitive.CharacterParser;
+import org.petitparser.parser.primitive.StringParser;
 
+import static org.petitparser.Assertions.assertAccept;
+import static org.petitparser.Assertions.assertFailure;
 import static org.petitparser.Assertions.assertSuccess;
 import static org.petitparser.parser.primitive.CharacterParser.of;
 
@@ -26,4 +31,35 @@ public void testTrimFlatten() {
     assertSuccess(parser, " a ", " a ");
     assertSuccess(parser, "  a  ", "  a  ");
   }
+
+  // https://github.com/petitparser/java-petitparser/issues/80
+  Parser createLine(String command) {
+    return StringParser.of(command + " ")
+        .seq(CharacterParser.word().plusLazy(Token.NEWLINE_PARSER))
+        .seq(Token.NEWLINE_PARSER);
+  }
+
+  @Test
+  public void testGithubIssue80_before() {
+    Parser parser = createLine("line1")
+        .seq(createLine("line2").optional())
+        .seq(createLine("line3"))
+        .end();
+    assertAccept(parser, "line1 value\nline3 value\n");
+    assertAccept(parser, "line1 value\nline2 value\nline3 value\n");
+    assertFailure(parser, "line1 value\nline2 !\nline3 value\n", 12, "line3  expected");
+  }
+
+  @Test
+  public void testGithubIssue80_after() {
+    Parser parser = createLine("line1")
+        .seq(
+            createLine("line3")
+                .or(createLine("line2")
+                    .seq(createLine("line3"))))
+        .end();
+    assertAccept(parser, "line1 value\nline3 value\n");
+    assertAccept(parser, "line1 value\nline2 value\nline3 value\n");
+    assertFailure(parser, "line1 value\nline2 !\nline3 value\n", 18, "letter or digit expected");
+  }
 }