Vanilla\Addon::check PHP Method

    public function check($trigger = false)
    {
        $issues = [];
        $rawKey = $this->getKey();
        $subdir = basename($this->getSubdir());
        // Check for missing fields.
        $required = ['key', 'type'];
        foreach ($required as $fieldName) {
            if (empty($this->info[$fieldName])) {
                $issues["required-{$fieldName}"] = "The {$fieldName} info field is required.";
            }
        }
        // Make sure the addon has a correct type.
        if ($this->getType()) {
            if (!in_array($this->getType(), [static::TYPE_ADDON, static::TYPE_THEME, static::TYPE_LOCALE])) {
                $type = $this->getType();
                $issues['type-invalid'] = "The addon has an invalid type ({$type}).";
            } elseif (empty($this->info['priority'])) {
                // Add a missing priority.
                $priorities = [static::TYPE_ADDON => static::PRIORITY_NORMAL, static::TYPE_LOCALE => static::PRIORITY_LOCALE, static::TYPE_THEME => static::PRIORITY_THEME];
                $this->info['priority'] = $priorities[$this->getType()];
            }
        }
        // Themes and locales must have a key that matches their subdirectories.
        if ($rawKey !== $subdir && in_array($this->getType(), [static::TYPE_LOCALE, static::TYPE_THEME])) {
            $issues['key-subdir-mismatch'] = "The addon key must match it's subdirectory name ({$rawKey} vs. {$subdir}).";
        }
        if ($this->getType() === static::TYPE_ADDON) {
            // Lowercase the keys of the other types.
            $key = strtolower($rawKey);
            if ($key !== $rawKey) {
                $this->info['key'] = $key;
                $this->info['keyRaw'] = $rawKey;
            }
            if (strcasecmp($key, basename($this->getSubdir())) !== 0) {
                $issues['key-subdir-mismatch-case'] = "The addon key must match it's subdirectory name ({$key} vs. {$subdir}).";
            }
        }
        if (!empty($this->special['otherPlugins'])) {
            $plugins = implode(', ', array_merge([$this->special['plugin']], $this->special['otherPlugins']));
            $issues['multiple-plugins'] = "The addon should have at most one plugin class ({$plugins}).";
        }
        if ($trigger && ($count = count($issues))) {
            $subdir = $this->getSubdir();
            trigger_error("The addon in {$subdir} has {$count} issues.", E_USER_NOTICE);
            foreach ($issues as $issue) {
                trigger_error($issue, E_USER_NOTICE);
            }
        }
        return $issues;
    }