if (typeof module !== "undefined") {
  PEG = require("../lib/peg.js");
}

beforeEach(function() {
  this.addMatchers({
    toChangeAST: function(grammar, details) {
      function matchDetails(value, details) {
        function isArray(value) {
          return Object.prototype.toString.apply(value) === "[object Array]";
        }

        function isObject(value) {
          return value !== null && typeof value === "object";
        }

        var i, key;

        if (isArray(details)) {
          if (!isArray(value)) { return false; }

          if (value.length !== details.length) { return false; }
          for (i = 0; i < details.length; i++) {
            if (!matchDetails(value[i], details[i])) { return false; }
          }

          return true;
        } else if (isObject(details)) {
          if (!isObject(value)) { return false; }

          for (key in details) {
            if (!(key in value)) { return false; }

            if (!matchDetails(value[key], details[key])) { return false; }
          }

          return true;
        } else {
          return value === details;
        }
      }

      var ast = PEG.parser.parse(grammar);

      this.actual(ast);

      this.message = function() {
        return "Expected the pass "
             + (this.isNot ? "not " : "")
             + "to change the AST " + jasmine.pp(ast) + " "
             + "to match " + jasmine.pp(details) + ", "
             + "but it " + (this.isNot ? "did" : "didn't") + ".";
      };

      return matchDetails(ast, details);
    }
  });
});