function DrupalJSONTest::testJSON

Tests converting PHP variables to JSON strings and back.

File

drupal/modules/simpletest/tests/common.test, line 2444

Tests for common.inc functionality.

Class

DrupalJSONTest

Tests converting PHP variables to JSON strings and back.

Code

function testJSON() {
  // Setup a string with the full ASCII table.
  // @todo: Add tests for non-ASCII characters and Unicode.
  $str = '';
  for ($i = 0; $i < 128; $i++) {
    $str .= chr($i);
  }
  // Characters that must be escaped.
  // We check for unescaped " separately.
  $html_unsafe = array('<', '>', '\'', '&');
  // The following are the encoded forms of: < > ' & "
  $html_unsafe_escaped = array(
    '\u003C',
    '\u003E',
    '\u0027',
    '\u0026',
    '\u0022',
  );

  // Verify there aren't character encoding problems with the source string.
  $this->assertIdentical(strlen($str), 128, t('A string with the full ASCII table has the correct length.'));
  foreach ($html_unsafe as $char) {
    $this->assertTrue(strpos($str, $char) > 0, t('A string with the full ASCII table includes @s.', array('@s' => $char)));
  }

  // Verify that JSON encoding produces a string with all of the characters.
  $json = drupal_json_encode($str);
  $this->assertTrue(strlen($json) > strlen($str), t('A JSON encoded string is larger than the source string.'));

  // The first and last characters should be ", and no others.
  $this->assertTrue($json[0] == '"', t('A JSON encoded string begins with ".'));
  $this->assertTrue($json[strlen($json) - 1] == '"', t('A JSON encoded string ends with ".'));
  $this->assertTrue(substr_count($json, '"') == 2, t('A JSON encoded string contains exactly two ".'));

  // Verify that encoding/decoding is reversible.
  $json_decoded = drupal_json_decode($json);
  $this->assertIdentical($str, $json_decoded, t('Encoding a string to JSON and decoding back results in the original string.'));

  // Verify reversibility for structured data. Also verify that necessary
  // characters are escaped.
  $source = array(
    TRUE,
    FALSE,
    0,
    1,
    '0',
    '1',
    $str,
    array(
      'key1' => $str,
      'key2' => array('nested' => TRUE),
    ),
  );
  $json = drupal_json_encode($source);
  foreach ($html_unsafe as $char) {
    $this->assertTrue(strpos($json, $char) === FALSE, t('A JSON encoded string does not contain @s.', array('@s' => $char)));
  }
  // Verify that JSON encoding escapes the HTML unsafe characters
  foreach ($html_unsafe_escaped as $char) {
    $this->assertTrue(strpos($json, $char) > 0, t('A JSON encoded string contains @s.', array('@s' => $char)));
  }
  $json_decoded = drupal_json_decode($json);
  $this->assertNotIdentical($source, $json, t('An array encoded in JSON is not identical to the source.'));
  $this->assertIdentical($source, $json_decoded, t('Encoding structured data to JSON and decoding back results in the original data.'));
}