phorge-arcanist/src/lint/linter/ArcanistPyFlakesLinter.php

<?php

/**
 * Uses "PyFlakes" to detect various errors in Python code.
 */
final class ArcanistPyFlakesLinter extends ArcanistExternalLinter {

  public function getInfoURI() {
    return 'https://pypi.python.org/pypi/pyflakes';
  }

  public function getInfoName() {
    return pht('PyFlakes');
  }

  public function getInfoDescription() {
    return pht(
      'PyFlakes is a simple program which checks Python source files for '.
      'errors.');
  }

  public function getLinterName() {
    return 'PYFLAKES';
  }

  public function getLinterConfigurationName() {
    return 'pyflakes';
  }

  public function getDefaultBinary() {
    $config = $this->getEngine()->getConfigurationManager();
    $prefix = $config->getConfigFromAnySource('lint.pyflakes.prefix');
    $bin = $config->getConfigFromAnySource('lint.pyflakes.bin', 'pyflakes');

    if ($prefix) {
      return $prefix.'/'.$bin;
    } else {
      return $bin;
    }
  }

  public function getVersion() {
    list($stdout) = execx('%C --version', $this->getExecutableCommand());

    $matches = array();
    if (preg_match('/^(?P<version>\d+\.\d+\.\d+)$/', $stdout, $matches)) {
      return $matches['version'];
    } else {
      return false;
    }
  }

  public function getInstallInstructions() {
    return pht('Install pyflakes with `pip install pyflakes`.');
  }

  public function shouldExpectCommandErrors() {
    return true;
  }

  public function supportsReadDataFromStdin() {
    return true;
  }

  protected function parseLinterOutput($path, $err, $stdout, $stderr) {
    $lines = phutil_split_lines($stdout, false);

    $messages = array();
    foreach ($lines as $line) {
      $matches = null;
      if (!preg_match('/^(.*?):(\d+): (.*)$/', $line, $matches)) {
        continue;
      }
      foreach ($matches as $key => $match) {
        $matches[$key] = trim($match);
      }

      $severity = ArcanistLintSeverity::SEVERITY_WARNING;
      $description = $matches[3];

      $error_regexp = '/(^undefined|^duplicate|before assignment$)/';
      if (preg_match($error_regexp, $description)) {
        $severity = ArcanistLintSeverity::SEVERITY_ERROR;
      }

      $message = new ArcanistLintMessage();
      $message->setPath($path);
      $message->setLine($matches[2]);
      $message->setCode($this->getLinterName());
      $message->setDescription($description);
      $message->setSeverity($severity);

      $messages[] = $message;
    }

    if ($err && !$messages) {
      return false;
    }

    return $messages;
  }

}