tool/src/test/java/org/antlr/test/TestSyntaxErrors.java

/*
 * [The "BSD license"]
 * Copyright (c) 2011 Terence Parr
 * All rights reserved.
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package org.antlr.test;

import org.antlr.tool.ErrorManager;
import org.junit.Test;

import static org.junit.Assert.*;

import java.io.File;

/** test runtime parse errors */
public class TestSyntaxErrors extends BaseTest {
	@Test public void testLL2() throws Exception {
		String grammar =
			"grammar T;\n" +
			"a : 'a' 'b'" +
			"  | 'a' 'c'" +
			";\n" +
			"q : 'e' ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", "ae", false);
		String expecting = "line 1:1 no viable alternative at input 'e'\n";
		String result = stderrDuringParse;
		assertEquals(expecting, result);
	}

	@Test public void testLL3() throws Exception {
		String grammar =
			"grammar T;\n" +
			"a : 'a' 'b'* 'c'" +
			"  | 'a' 'b' 'd'" +
			"  ;\n" +
			"q : 'e' ;\n";
		System.out.println(grammar);
		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", "abe", false);
		String expecting = "line 1:2 no viable alternative at input 'e'\n";
		String result = stderrDuringParse;
		assertEquals(expecting, result);
	}

	@Test public void testLLStar() throws Exception {
		String grammar =
			"grammar T;\n" +
			"a : 'a'+ 'b'" +
			"  | 'a'+ 'c'" +
			";\n" +
			"q : 'e' ;\n";
		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", "aaae", false);
		String expecting = "line 1:3 no viable alternative at input 'e'\n";
		String result = stderrDuringParse;
		assertEquals(expecting, result);
	}

	@Test public void testSynPred() throws Exception {
		String grammar =
			"grammar T;\n" +
			"a : (e '.')=> e '.'" +
			"  | (e ';')=> e ';'" +
			"  | 'z'" +
			"  ;\n" +
			"e : '(' e ')'" +
			"  | 'i'" +
			"  ;\n";
		System.out.println(grammar);
		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", "((i))z", false);
		String expecting = "line 1:1 no viable alternative at input '('\n";
		String result = stderrDuringParse;
		assertEquals(expecting, result);
	}

	@Test public void testLL1ErrorInfo() throws Exception {
		String grammar =
			"grammar T;\n" +
			"start : animal (AND acClass)? service EOF;\n" +
			"animal : (DOG | CAT );\n" +
			"service : (HARDWARE | SOFTWARE) ;\n" +
			"AND : 'and';\n" +
			"DOG : 'dog';\n" +
			"CAT : 'cat';\n" +
			"HARDWARE: 'hardware';\n" +
			"SOFTWARE: 'software';\n" +
			"WS : ' ' {skip();} ;" +
			"acClass\n" +
			"@init\n" +
			"{ System.out.println(computeContextSensitiveRuleFOLLOW().toString(tokenNames)); }\n" +
			"  : ;\n";
		String result = execParser("T.g", grammar, "TParser", "TLexer", "start", "dog and software", false);
		String expecting = "{HARDWARE,SOFTWARE}\n";
		assertEquals(expecting, result);
	}

	@Test public void testStrayBracketRecovery() {
		String grammar =
			"grammar T;\n" +
			"options {output = AST;}\n" +
			"tokens{NODE;}\n" +
			"s : a=ID INT -> ^(NODE[$a]] INT);\n" +
			"ID: 'a'..'z'+;\n" +
			"INT: '0'..'9'+;\n";

		ErrorQueue errorQueue = new ErrorQueue();
		ErrorManager.setErrorListener(errorQueue);

		boolean found =
			rawGenerateAndBuildRecognizer(
				"T.g", grammar, "TParser", "TLexer", false);

		assertFalse(found);
		assertEquals(
			"[error(100): :4:27: syntax error: antlr: dangling ']'? make sure to escape with \\]]",
			errorQueue.errors.toString());
	}

	/**
	 * This is a regression test for antlr/antlr3#61.
	 * https://github.com/antlr/antlr3/issues/61
	 */
	@Test public void testMissingAttributeAccessPreventsCodeGeneration() throws Exception {
		String grammar =
			"grammar T;\n" +
			"options {\n" +
			"    backtrack = true; \n" +
			"}\n" +
			"// if b is rule ref, gens bad void x=null code\n" +
			"a : x=b {Object o = $x; System.out.println(\"alt1\");}\n" +
			"  | y=b\n" +
			"  ;\n" +
			"\n" +
			"b : 'a' ;\n" ;

		ErrorQueue errorQueue = new ErrorQueue();
		ErrorManager.setErrorListener(errorQueue);
		boolean success = rawGenerateAndBuildRecognizer("T.g", grammar, "TParser", "TLexer", false);
		assertFalse(success);
		assertEquals(
			"[error(117): "+tmpdir.toString()+File.separatorChar+"T.g:6:9: missing attribute access on rule scope: x]",
			errorQueue.errors.toString());
	}
}