public CheckLevel level()

in java/com/google/javascript/jscomp/JsCompilerWarnings.java [58:121]
36 lines of code
12 McCabe index (conditional complexity)

  public CheckLevel level(JSError error) {
    // Closure Rules will always ignore these checks no matter what.
    if (Diagnostics.IGNORE_ALWAYS.contains(error.getType())) {
      return CheckLevel.OFF;
    }

    // Some checks, e.g. linting, are handled *exclusively* by JsChecker.
    if (Diagnostics.JSCHECKER_ONLY_SUPPRESS_CODES.contains(error.getType().key)) {
      return CheckLevel.OFF;
    }

    // Synthetic code is generated by compiler passes.
    if (isInSyntheticCode(error)) {
      // These are the checks we know synthetic code currently isn't very good at following.
      if (Diagnostics.IGNORE_FOR_SYNTHETIC.contains(error.getType())) {
        return CheckLevel.OFF;
      }
      // If there are any others, we'll display a warning, because it's impossible for the user to
      // address these errors. We're not ignoring them entirely because we want to encourage users
      // to file bugs so the compiler pass can be fixed.
      return CheckLevel.WARNING;
    }

    // Some errors are independent of code, e.g. flag misuse.
    if (error.getSourceName() == null) {
      return CheckLevel.ERROR;
    }
    
    // We provide an escape hatch for situations in which it's not possible (or too burdensome) to
    // add a suppress code to the closure_js_library() rule responsible for the error.
    if (globalSuppressions.contains(error.getType())) {
      return CheckLevel.OFF;
    }

    for (String module : convertPathToModuleName(error.getSourceName(), roots).asSet()) {
      if (legacyModules.contains(module)) {
        // Ignore it entirely if it's very noisy.
        if (Diagnostics.IGNORE_FOR_LEGACY.contains(error.getType())) {
          return CheckLevel.OFF;
        }
        // Otherwise downgrade to a warning, since it's not easily actionable.
        return CheckLevel.WARNING;
      } else if (suppressions.containsEntry(module, error.getType())) {
        // If a closure_js_library() defined this source file, then check if that library rule
        // defined a suppress code to make this error go away.
        return CheckLevel.OFF;
      }
    }

    switch (error.getDefaultLevel()) {
      case OFF:
        /**
         * Treat any user invisible diagnostics as safe by default.
         *
         * <p>This lets new diagnostics be added to JSCompiler without immediately being errors,
         * whcih is useful for staged rollouts.
         */
        return CheckLevel.OFF;

      default:
        // Treat any user visible diagnostic as an error by default.
        return CheckLevel.ERROR;
    }
  }