/**
* Returns a {@link Statement}: apply all static {@link Value} fields annotated with {@link Rule}.
*
* @param statement the base statement
* @return a WithClassRules statement if any class-level {@link Rule}s are found, or the base
* statement
*/
private Statement withClassRules(Statement statement) {
final List<TestRule> classRules = classRules();
if (classRules.isEmpty()) {
return statement;
}
Statement next = statement;
for (final TestRule classRule : classRules) {
next = classRule.apply(next, getDescription());
}
return next;
}
/**
* Ad hoc invocation of a callable wrapped in the start/finish behaviour of a JUnit rule.
*
* @param callable the callable to execute
* @param rule the rule to wrap it in
* @throws Exception on any exception thrown by the callable or the rule
*/
public static <V> V callWith(Callable<V> callable, TestRule rule) throws Exception {
class CallableStatement extends Statement {
final Callable<V> callable;
V result;
CallableStatement(Callable<V> callable) {
this.callable = callable;
}
@Override
public void evaluate() throws Throwable {
result = callable.call();
}
}
try {
CallableStatement statement = new CallableStatement(callable);
rule.apply(statement, Description.EMPTY).evaluate();
return statement.result;
} catch (Throwable t) {
if (t instanceof Exception) {
throw (Exception) t;
} else {
throw (Error) t;
}
}
}