* Make method for searching parents for toml file public
* Make method for loading config from path directly public, tweak the
API since it was never returning None
- `--dump-default-config` outputs the default configuration to the
specified file as TOML and then exits.
- `--dump-minimal-config` is checked after formatting files as normal.
If present, any configuration options that were checked during
formatting are written to the specified file as TOML.
- These options were added only to `rustfmt`, not to `cargo fmt`. They
can be specified when using `cargo fmt` by placing them after `--`.
- It would have been nice if the filename was optional, so you could
run just `rusfmt --dump-minimal-config build.rs` to have it output to
`rustfmt.toml`. However, this doesn't do what you might expect: it
outputs the config to `build.rs`!
This API isn't fantastic, but it's the best I can come up with without
something like `concat_idents!()`. There are relatively few places where
config is set, to hopefully the ugliness isn't disastrous.
Change previous occurences of `config.item = value` to this new API,
rather than using `config.override_value()`. Undo the changes to
`override_value()`, as it's no longer important to propogate the error
to the caller. Add a test for the new interface.
Preparation for #865, which proposes adding a flag which outputs which
config options are used during formatting.
This PR should not make any difference to functionality. A lot of this
was search-and-replace.
Some areas worthy of review/discussion:
- The method for each config item returns a clone of the underlying
value. We can't simply return an immutable reference, as lots of
places in the code expect to be able to pass the returned value as
`bool` (not `&bool). It would be nice if the `bool` items could
return a copy, but the more complex types a borrowed reference... but
unfortunately, I couldn't get the macro to do this.
- A few places (mostly tests and `src/bin/rustfmt.rs`) were overriding
config items by modifying the fields of the `Config` struct directly.
They now use the existing `override_value()` method, which has been
modified to return a `Result` for use by `src/bin/rustfmt.rs`. This
benefits of this are that the complex `file_lines` and `write_mode`
strings are now parsed in one place (`Config.override_value`) instead
of multiple. The disadvantages are that it moves the compile-time
checks for config names to become run-time checks.
