jison-es/tests/parser/errorlab.js

Fork of jison that emits parsers as ES modules

var Jison = require("../setup").Jison,
    Lexer = require("../setup").Lexer,
    assert = require("assert");

exports["test error caught"] = function () {
    var lexData = {
        rules: [
           ["x", "return 'x';"],
           ["y", "return 'y';"],
           [".", "return 'ERR';"]
        ]
    };
    var grammar = {
        bnf: {
            "A" :['A x',
                  'A y',
                  [ 'A error', "return 'caught';" ],
                   ''      ]
        }
    };

    var parser = new Jison.Parser(grammar, {type: "lr0"});
    parser.lexer = new Lexer(lexData);
    assert.ok(parser.parse('xxy'), "should parse");
    assert.equal(parser.parse('xyg'), "caught", "should return 'caught'");
};

exports["test error recovery"] = function () {
    var lexData = {
        rules: [
           ["x", "return 'x';"],
           ["y", "return 'y';"],
           [".", "return 'ERR';"]
        ]
    };
    var grammar = {
        bnf: {
            "A" :['A x',
                  ['A y', "return 'recovery'"],
                  'A error',
                   ''      ]
        }
    };

    var parser = new Jison.Parser(grammar, {type: "lr0"});
    parser.lexer = new Lexer(lexData);
    assert.equal(parser.parse('xxgy'), "recovery", "should return foo");
};

exports["test deep error recovery"] = function () {
    var lexData = {
        rules: [
           ["x", "return 'x';"],
           ["y", "return 'y';"],
           ["g", "return 'g';"],
           [";", "return ';';"],
           [".", "return 'ERR';"]
        ]
    };
    var grammar = {
        bnf: {
            "S" :['g A ;',
                  ['g error ;', 'return "nested"']
                      ],
            "A" :['A x',
                  'x' ]
        }
    };

    var parser = new Jison.Parser(grammar, {type: "lr0"});
    parser.lexer = new Lexer(lexData);
    assert.ok(parser.parse('gxxx;'), "should parse");
    assert.equal(parser.parse('gxxg;'), "nested", "should return nested");
};

exports["test no recovery"] = function () {
    var lexData = {
        rules: [
           ["x", "return 'x';"],
           ["y", "return 'y';"],
           [".", "return 'ERR';"]
        ]
    };
    var grammar = {
        bnf: {
            "A" :['A x',
                  ['A y', "return 'recovery'"],
                   ''      ]
        }
    };

    var parser = new Jison.Parser(grammar, {type: "lr0"});
    parser.lexer = new Lexer(lexData);
    assert.throws(function (){parser.parse('xxgy')}, "should throw");
};

exports["test error after error recovery"] = function () {
    var lexData = {
        rules: [
           ["x", "return 'x';"],
           ["y", "return 'y';"],
           ["g", "return 'g';"],
           [".", "return 'ERR';"]
        ]
    };
    var grammar = {
        bnf: {
            "S" :['g A y',
                  ['g error y', 'return "nested"']
                      ],
            "A" :['A x',
                  'x' ]
        }
    };

    var parser = new Jison.Parser(grammar, {type: "lr0"});
    parser.lexer = new Lexer(lexData);
    assert.throws(function (){parser.parse('gxxx;')}, "should return bar");
};

exports["test throws error despite recovery rule"] = function() {
    var lexData2 = {
        rules: [
           ["0", "return 'ZERO';"],
           ["\\+", "return 'PLUS';"],
           [";", "return ';';"],
           [".", "return 'INVALID'"],
           ["$", "return 'EOF';"]
        ]
    };
    var grammar = {
        bnf: {
            "S" :[ [ "Exp EOF",    "return $1" ]],
            "Exp" :[ [ "E ;",    "$$ = $1;" ],
                     [ "E error", "$$ = $1;" ]],
            "E" :[ [ "E PLUS T", "$$ = ['+',$1,$3]"  ],
                   [ "T",        "$$ = $1" ]  ],
            "T" :[ [ "ZERO",     "$$ = [0]" ] ]
        }
    };

    var parser = new Jison.Parser(grammar, {debug: true});
    parser.lexer = new Lexer(lexData2);

    var expectedAST = ["+", ["+", [0], [0]], [0]];

    assert.throws(function (){(parser.parse("0+0+0>"), expectedAST);});
};

exports["test correct AST after error recovery abrupt end"] = function() {
    var lexData2 = {
        rules: [
           ["0", "return 'ZERO';"],
           ["\\+", "return 'PLUS';"],
           [";", "return ';';"],
           ["$", "return 'EOF';"],
           [".", "return 'INVALID';"]
        ]
    };
    var grammar = {
        bnf: {
            "S" :[ [ "Exp EOF",    "return $1" ]],
            "Exp" :[ [ "E ;",    "$$ = $1;" ],
                     [ "E error", "$$ = $1;" ]],
            "E" :[ [ "E PLUS T", "$$ = ['+',$1,$3]"  ],
                   [ "T",        "$$ = $1" ]  ],
            "T" :[ [ "ZERO",     "$$ = [0]" ] ]
        }
    };

    var parser = new Jison.Parser(grammar);
    parser.lexer = new Lexer(lexData2);

    var expectedAST = ["+", ["+", [0], [0]], [0]];

    assert.deepEqual(parser.parse("0+0+0"), expectedAST);
};


exports["test bison error recovery example"] = function() {
    var lexData2 = {
        rules: [
           ["0", "return 'ZERO';"],
           ["\\+", "return 'PLUS';"],
           [";", "return ';';"],
           ["$", "return 'EOF';"],
           [".", "return 'INVALID';"]
        ]
    };
    var grammar = {
        bnf: {
            "S" :[ [ "stmt stmt EOF",    "return $1" ]],
            "stmt" :[ [ "E ;",    "$$ = $1;" ],
                     [ "error ;", "$$ = $1;" ]],
            "E" :[ [ "E PLUS T", "$$ = ['+',$1,$3]"  ],
                   [ "T",        "$$ = $1" ]  ],
            "T" :[ [ "ZERO",     "$$ = [0]" ] ]
        }
    };

    var parser = new Jison.Parser(grammar);
    parser.lexer = new Lexer(lexData2);

    assert.ok(parser.parse("0+0++++>;0;"), "should recover");
};