Example of a failing ANTLR MySQL Parser

mysql_simple_test.go

/**
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package mysql_test

import (
	"bramp.net/antlr4-grammars/mysql"

	"github.com/antlr/antlr4/runtime/Go/antlr"
	"path/filepath"
	"testing"
	"unicode"
)

// CaseChangingStream wraps an existing CharStream, but upper cases, or
// lower cases the input before it is tokenized.
type CaseChangingStream struct {
	antlr.CharStream
	upper bool
}

func (is *CaseChangingStream) LA(offset int) int {
	in := is.CharStream.LA(offset)
	if in < 0 {
		// Such as antlr.TokenEOF which is -1
		return in
	}
	if is.upper {
		return int(unicode.ToUpper(rune(in)))
	}
	return int(unicode.ToLower(rune(in)))
}

func newCharStream(filename string) (antlr.CharStream, error) {
	input, err := antlr.NewFileStream(filepath.Join("..", filename))
	if err != nil {
		return nil, err
	}
	return &CaseChangingStream{input, true}, nil
}

// TestingErrorListener is a antlr.ErrorListener which fails the given test
// if a SyntaxError is found. The other Report errors are ignored.
type TestingErrorListener struct {
	*antlr.DefaultErrorListener

	t    *testing.T
	idx  int
	name string
}

func (l *TestingErrorListener) SyntaxError(recognizer antlr.Recognizer, offendingSymbol interface{}, line, column int, msg string, e antlr.RecognitionException) {
	l.t.Errorf("[%d] %s: SyntaxError %d:%d: %s", l.idx, l.name, line, column, msg)
}

func TestMySqlParser(t *testing.T) {
	var examples = []string{
		"grammars-v4/mysql/examples/ddl_create.sql",
		"grammars-v4/mysql/examples/dml_delete.sql",
	}

	for i, file := range examples {
		input, err := newCharStream(file)
		if err != nil {
			t.Errorf("Failed to open example file: %s", err)
		}

		// Create the Lexer
		lexer := mysql.NewMySqlLexer(input)
		stream := antlr.NewCommonTokenStream(lexer, antlr.TokenDefaultChannel)

		// Create the Parser
		p := mysql.NewMySqlParser(stream)
		p.BuildParseTrees = true
		p.AddErrorListener(&TestingErrorListener{t: t, idx: i, name: file})

		// Finally test
		p.Root()
	}
}