bool/test/parser_test.js

Boolean expression evaluator

var parser = require('../lib').parser;
var Evaluator = require('../lib/evaluator');
var assert = require('assert');

describe('Bool', function() {
  it('sole tag', function() {
    var expr = parser.parse('@a');

    assert.equal(true, expr.accept(new Evaluator(), ['@a']));
    assert.equal(false, expr.accept(new Evaluator(), ['@b']));
  });

  it('does and', function() {
    var expr = parser.parse('@a && @b');
    assert.equal(true, expr.accept(new Evaluator(), ['@a', '@b']));
    assert.equal(false, expr.accept(new Evaluator(), ['@a']));
    assert.equal(false, expr.accept(new Evaluator(), ['@b']));
    assert.equal(false, expr.accept(new Evaluator(), []));
  });

  it('Does it all', function() {
    var expr = parser.parse('@a && @b || !@c');
    assert.equal(true, expr.accept(new Evaluator(), ['@a', '@b']));
    assert.equal(false, expr.accept(new Evaluator(), ['@c']));
    assert.equal(true, expr.accept(new Evaluator(), []));
  });

  it('double negation', function() {
    var expr = parser.parse('!!@a');
    assert.equal(true, expr.accept(new Evaluator(), ['@a']));
    assert.equal(false, expr.accept(new Evaluator(), ['@b']));
  });

  it('tag syntax', function() {
    var expr = parser.parse('!@a1A');
    assert.equal(false, expr.accept(new Evaluator(), ['@a1A']));
  });

  it('throws exception on scanner error', function() {
    try {
      parser.parse(      // line,token_start_col
        "          \n" + // 1
        "          \n" + // 2
        "  a       \n" + // 3,3
        "    ^     \n"   // 4,5
       //0123456789
      );
      throw new Error("should fail");
    } catch(expected) {
      assert.equal(
        "Lexical error on line 4. Unrecognized text.\n" +
        "...      a           ^     \n" +
        "---------------------^"
        , expected.message);
      assert.deepEqual({
        text: '',
        token: null,
        line: 3 // Jison lines are zero-indexed.
      }, expected.hash);
    }
  });

  it('throws exception on parse error', function() {
    try {
      parser.parse(
                         // line,token_start_col
        "          \n" + // 1
        "          \n" + // 2
        "  a       \n" + // 3,3
        "    ||    \n" + // 4,5
        "      c   \n" + // 5,7
        "        &&"     // 6,9
      ///0123456789
      );
      throw new Error("should fail");
    } catch(expected) {
      assert.equal(
        "Parse error on line 6:\n" +
        "...     c           &&\n" +
        "----------------------^\n" +
        "Expecting 'TOKEN_VAR', 'TOKEN_NOT', 'TOKEN_LPAREN', got 'EOF'"
        , expected.message);
      assert.deepEqual({
        text: '',
        token: 'EOF',
        line: 5,
        loc: { first_line: 6, last_line: 6, first_column: 8, last_column: 10 },
        expected: [ '\'TOKEN_VAR\'', '\'TOKEN_NOT\'', '\'TOKEN_LPAREN\'' ]
      }, expected.hash);
    }
  });
});