text: "use strict";
  
  var test = require('tape');
  var mapnik = require('../');
  
  
  test('should throw with invalid usage', (assert) => {
    // no 'new' keyword
    assert.throws(function() { mapnik.Expression(); });
    // invalid args
    assert.throws(function() { new mapnik.Expression(); });
    assert.throws(function() { new mapnik.Expression(1); });
    assert.throws(function() { new mapnik.Expression('[asdfadsa]]'); });
    assert.end();
  });
  
  test('should accept complex expressions', (assert) => {
    // valid expression strings
    var expr = new mapnik.Expression('[ATTR]');
    expr = new mapnik.Expression('[ATTR]+2');
    expr = new mapnik.Expression('[ATTR]/2');
  
    expr = new mapnik.Expression('[ATTR1]/[ATTR2]');
    assert.equal(expr.toString(), '[ATTR1]/[ATTR2]');
  
    expr = new mapnik.Expression('\'literal\'');
    assert.equal(expr.toString(), "'literal'");
    assert.end();
  });
  
  test('should support evaluation to js types', (assert) => {
    var expr = new mapnik.Expression("[attr]='value'");
    var feature = new mapnik.Feature.fromJSON('{"type":"Feature","properties":{"attr":"value"},"geometry":null}');
  
    // Test bad parameters
    assert.throws(function() { expr.evaluate(); });
    assert.throws(function() { expr.evaluate(null); });
    assert.throws(function() { expr.evaluate(feature, null); });
    assert.throws(function() { expr.evaluate(feature, {variables:null}); });
  
    assert.equal(expr.evaluate(feature), true);
    assert.equal(expr.evaluate(feature).toString(), 'true');
    assert.end();
  });
  
  test('should support evaluation with variables', (assert) => {
    var expr = new mapnik.Expression("[integer]=@integer and [bool]=@bool and [string]=@string and [double]=@double");
    var options = {variables: { 'integer': 22, 'bool': true, 'string': "string", 'double': 1.0001 } };
    var feature = new mapnik.Feature.fromJSON('{"type":"Feature","properties":{"integer":22, "bool": 1, "string": "string", "double":1.0001},"geometry":null}');
    assert.equal(expr.evaluate(feature, options), true);
    assert.equal(expr.evaluate(feature, options).toString(), 'true');
    assert.end();
  });
  