== Why is this an issue?

An ``++assert++`` is inappropriate for parameter validation because assertions can be disabled at runtime in the JVM, meaning that a bad operational setting would completely eliminate the intended checks. Further, ``++assert++``s that fail throw ``++AssertionError++``s, rather than throwing some type of ``++Exception++``. Throwing ``++Error++``s is completely outside of the normal realm of expected ``++catch++``/``++throw++`` behavior in normal programs.


This rule raises an issue when a ``++public++`` method uses one or more of its parameters with ``++assert++``s.


=== Noncompliant code example

[source,java]
----
 public void setPrice(int price) {
  assert price >= 0 && price <= MAX_PRICE;
  // Set the price
 } 
----


=== Compliant solution

[source,java]
----
 public void setPrice(int price) {
  if (price < 0 || price > MAX_PRICE) {
    throw new IllegalArgumentException("Invalid price: " + price);
  }
  // Set the price
 } 
----


== Resources

https://docs.oracle.com/javase/7/docs/technotes/guides/language/assert.html[Programming With Assertions]

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