Function validateIcon

src/node/validate.ts:39–109

* Validate icon field in manifest * @param iconPath - The icon path from manifest.json * @param baseDir - The base directory containing the manifest * @returns Validation result with errors and warnings

(
  iconPath: string,
  baseDir: string,
)

 * @returns Validation result with errors and warnings
 */
function validateIcon(
  iconPath: string,
  baseDir: string,
): { valid: boolean; errors: string[]; warnings: string[] } {
  const errors: string[] = [];
  const warnings: string[] = [];

  const isRemoteUrl =
    iconPath.startsWith("http://") || iconPath.startsWith("https://");
  const hasVariableSubstitution = iconPath.includes("${__dirname}");
  const isAbsolutePath = isAbsolute(iconPath);

  // Warn about remote URLs (best practice: use local files)
  if (isRemoteUrl) {
    warnings.push(
      "Icon path uses a remote URL. " +
        'Best practice for local MCP servers: Use local files like "icon": "icon.png" for maximum compatibility. ' +
        "Claude Desktop currently only supports local icon files in bundles.",
    );
  }

  // Check for ${__dirname} variable (error - doesn't work)
  if (hasVariableSubstitution) {
    errors.push(
      "Icon path should not use ${__dirname} variable substitution. " +
        'Use a simple relative path like "icon.png" instead of "${__dirname}/icon.png".',
    );
  }

  // Check for absolute path (error - not portable)
  if (isAbsolutePath) {
    errors.push(
      "Icon path must be relative to the bundle root, not an absolute path. " +
        `Found: "${iconPath}"`,
    );
  }

  // Only proceed with file checks if the path looks like a local file
  if (!isRemoteUrl && !isAbsolutePath && !hasVariableSubstitution) {
    // Check file existence
    const fullIconPath = join(baseDir, iconPath);
    if (!existsSync(fullIconPath)) {
      errors.push(`Icon file not found at path: ${iconPath}`);
    } else {
      try {
        // Check PNG format
        const buffer = readFileSync(fullIconPath);
        if (!isPNG(buffer)) {
          errors.push(
            `Icon file must be PNG format. The file at "${iconPath}" does not appear to be a valid PNG file.`,
          );
        } else {
          // File exists and is a valid PNG - add recommendation
          warnings.push(
            "Icon validation passed. Recommended size is 512×512 pixels for best display in Claude Desktop.",
          );
        }
      } catch (error) {