ktlint arcanist plugin?

[martijnthe]

In your blog post , you mention having a plugin for arcanist. Supposedly it’s only 65 lines of php code. Nonetheless it would be nice to not have to reinvent the wheel. It would be awesome if you could open-source the plug-in!

thanks 🙏

See also pinterest/arcanist-linters#47 (comment)

[shashachu]

Sure - will work on that. Thanks for the nudge.

[kenyee]

+1...please share 😄

[shashachu]

Here is approximately what we use. It worked well for us when we first switched to Kotlin and could gradually run ktlint on the codebase as more Kotlin appeared, as Arcanist lint only runs on changed files.

<?php
final class ArcanistKotlinLinter extends ArcanistLinter
{
    public function getInfoName()
    {
        return "Kotlin Linter";
    }

    public function getInfoDescription() 
    {
        return "Runs ktlint command line on Kotlin files.";
    }

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

    public function getLinterName()
    {
        return 'Kotlin Linter';
    }

    protected function shouldLintDirectories()
    {
        return true;
    }

    public function lintPath($path)
    {
        $root = $this->getEngine()->getWorkingCopy()->getProjectRoot();

        $cwd = getcwd();
        chdir($root);

        $jarPath = "./path/to/your/custom/rules.jar";

        if (!file_exists($jarPath)) {
            throw new ArcanistUsageException("Can't find custom rules jar.");
        }

        $filePath = Filesystem::resolvePath($path, $root);
        $orig = file_get_contents($filePath);

        // Run with -F so that any violations that can be auto-corrected are.
        // Also link in our custom ruleset
        $cmd = "path/to/ktlint --experimental -F -R " . $jarPath . " %s";
        // Run the command line ktlint on the path
        list ($err, $stdout, $stderr) = exec_manual($cmd, $path);

        // Split the output by line
        $output_lines = explode("\n", $stdout);

        $formatted = file_get_contents($filePath);

        if ($orig != $formatted) {
            $message = id(new ArcanistLintMessage())
                  ->setPath($path)
                  ->setLine(1)
                  ->setChar(1)
                  ->setGranularity(ArcanistLinter::GRANULARITY_FILE)
                  ->setCode('KFMT')
                  ->setSeverity(ArcanistLintSeverity::SEVERITY_AUTOFIX)
                  ->setName('Code style violation')
                  ->setDescription("'$path' has code style errors.")
                  ->setOriginalText($orig)
                  ->setReplacementText($formatted);
            $this->addLintMessage($message);
        }

        file_put_contents($filePath, $orig);

        if (sizeof($output_lines) > 0) {
            $pattern = "/(^[\S]+.kt):([\d]+):([\d]+):\S* (.+$)/";

            foreach ($output_lines as $line) {
                preg_match($pattern, $line, $matches);
                if (!empty($matches)) {
                    $desc = $matches[4];
                    // The autofixable errors have already been autocorrected, so only show the true errors here.
                    if (!$this->canAutofix($desc)) {
                        $message = new ArcanistLintMessage();
                        $message->setName("Kotlin Lint Error");
                        $message->setPath($path);
                        $message->setDescription($matches[4]);
                        $message->setLine(intval($matches[2]));
                        $message->setSeverity(ArcanistLintSeverity::SEVERITY_ERROR);

                        $this->addLintMessage($message);
                    }
                }
            }
        }

        chdir($cwd);
    }

    private function canAutofix($text) {
        return strpos($text, "(cannot be auto-corrected)") === false;
    }
}