Clean Code

try {
return am == null ? 0 : (Double) am.get();
} catch (Exception e) {
return 0.0;
}
}
And all the tests pass! That was pretty painless. So now let’s make sure all the error
processing works correctly. The next test case checks that an error is declared if an
unparseable string is fed to a 
##
argument.
public void testInvalidDouble() throws Exception {
Args args = new Args("x##", new String[] {"-x","Forty two"});
assertFalse(args.isValid());
assertEquals(0, args.cardinality());
assertFalse(args.has('x'));
assertEquals(0, args.getInt('x'));

---

239
String Arguments
assertEquals("Argument -x expects a double but was 'Forty two'.", 
args.errorMessage());
}
---
public String errorMessage() throws Exception {
switch (errorCode) {
case OK:
throw new Exception("TILT: Should not get here.");
case UNEXPECTED_ARGUMENT:
return unexpectedArgumentMessage();
case MISSING_STRING:
return String.format("Could not find string parameter for -%c.", 
errorArgumentId);
case INVALID_INTEGER:
return String.format("Argument -%c expects an integer but was '%s'.", 
errorArgumentId, errorParameter);
case MISSING_INTEGER:
return String.format("Could not find integer parameter for -%c.", 
errorArgumentId);
case INVALID_DOUBLE:
return String.format("Argument -%c expects a double but was '%s'.",
errorArgumentId, errorParameter);
case MISSING_DOUBLE:
return String.format("Could not find double parameter for -%c.", 
errorArgumentId);
}
return "";
}
And the tests pass. The next test makes sure we detect a missing 
double
argument properly.