Throw error on storeOptionsAsProperties() after setting option values

[aweebit]

Cherry-picked from #1926 for better separation of concerns.

Additionally, a unit test has been added to cover the error.

Problem

program.setOptionValue('foo', 'bar');
console.log(program.getOptionValue('foo')); // 'bar'
console.log(program.opts()); // { foo: 'bar' }
program.storeOptionsAsProperties(); // allowed!
console.log(program.getOptionValue('foo')); // undefined
console.log(program.opts()); // {}

ChangeLog

Changed

• Breaking: throw error when calling .storeOptionsAsProperties() after setting an option value

[shadowspawn]

Passing false is same as the default state, so it isn't the interesting case and pretty unlikely to be encountered:

Suggested change

	program.storeOptionsAsProperties(false);
	program.storeOptionsAsProperties();

(I know the throw does not currently care, but I would still like to test the interesting case.)

[aweebit]

I actually just copied the call from above, and before doing that, I took a minute to think about why you'd decided to pass false in that previous test. The way I ended up explaining it to myself is that you'd probably wanted to test the unproblematic call that would not even change anything if it were allowed because that demonstrates how intransigent the check is. It is obvious an error will be thrown when passing true or nothing if even passing false results in an error (despite the fact that the call would simply be no-op otherwise). That last bit is not so obvious, so that is why I think tests with false might actually be the more interesting ones here.

[shadowspawn]

I actually just copied the call from above

Oh, digging... The previous test logic dates back to when the default was to store options as properties, and was not correctly updated when the default behaviour changed. Please change the previous test too! Either pass true or no param, either is fine.

[shadowspawn]

This might help someone making a gradual (and big) transition away from storing options as properties and as first step switching from program.foo = true to program.setOptionValue('foo', true).

One minor change requested.

[shadowspawn]

LGTM

[abetomo]

+1