Updates the derive example handling environment variables to illustrate
the case where it contains a sensitive value which should not be
displayed on the help screen.
Closes https://github.com/clap-rs/clap/issues/2101
Using `App::get_matches` from the integration tests meant that any
CLI arguments passed to libtest would also be captured by clap, often
causing the tests to fail.
For example, running `cargo test --test help -- --nocapture` would
result in several failed tests, even though `cargo test --test help`
worked fine. This was very surprising/confusing.
This commit makes the tests no longer implicitly rely on the value of
`env::args_os()`, which means developers can now provide arguments to
libtest without failures.
The YAML null value is called `null` in YAML, not `Null`. yaml-rust
handles those values according to spec, so we should use the correct
capitalization.
See https://yaml.org/spec/1.2/spec.html#id2803362 for more
information.
The macro `yaml_opt_str` is only used in `yaml_tuple3`, which again is
only used for `default_value_if`. Unfortunately, the current test
doesn't make sense, as a v.is_null() indicates a Yaml::Null, on wich
`as_str()` always returns `None`. Instead, the condition should be
negated, as the documentation of `default_value_if` hints:
> **NOTE:** If using YAML the values should be laid out as
> follows (`None` can be represented as `null` in YAML)
The case `$v.is_null()` should therefore lead to `None`, whereas all
other cases should be interpreted `as_str()`.
While reading the code for the yaml translation, I've noticed that
there is a bug in the macro `yaml_opt_str` as well as a wrong `null`
value in the test fixture.
These tests add the expected behaviour on the given fixture, e.g.
prog
and
prog <WRONG>
where `<WRONG>` is **not** `other` should yield `None` for
`"positional2"`, whereas
prog other
should yield "something" and
prog --flag ARBITRARY_VALUE
should yield "some". The first two tests
- default_value_if_not_triggered
- default_value_if_not_triggered_by_argument
fail, as the second positional arguments *gets set*, although its
conditions aren't fulfilled.
