ReplaceNestedConditionalWithGuardClauses.java

package ch9;

/* 
 * A method has conditional behavior that does not make clear the normal path of execution
 * 
 * Use guard clauses for all the special cases
 */
class ReplaceNestedConditionalWithGuardClauses {
  public double getPayAmount() {
    double result;
    if (_isDead)
      result = deadAmount();
    else {
      if (_isSeparated)
        result = separatedAmount();
      else {
        if (_isRetired)
          result = retiredAmount();
        else
          result = normalPayAmount();
      }
    }
    return result;
  }
}

class ReplaceNestedConditionalWithGuardClausesReversing {
  public double getAdjustedCapital() {
    double result = 0.0;
    if (_capital > 0.0) {
      if (_intRate > 0.0 && _duration > 0.0) {
        result = (_income / _duration) * ADJ_FACTOR;
      }
    }
    return result;
  }
}

class ReplaceNestedConditionalWithGuardClausesRefactored {
  public double getPayAmount() {
    if (_isDead)
      return deadAmount();
    if (_isSeparated)
      return separatedAmount();
    if (_isRetired)
      return retiredAmount();
    return normalPayAmount();
    ;
  }
}

class ReplaceNestedConditionalWithGuardClausesReversingRefactored {
  public double getAdjustedCapital() {
    if (_capital <= 0.0)
      return 0.0;
    if (_intRate <= 0.0 || _duration <= 0.0)
      return 0.0;
    return (_income / _duration) * ADJ_FACTOR;
  }
}