Improve "unknown field" error messages

[smoelius]

Fixes #8806

Sample output:

error: error reading Clippy's configuration file `/home/smoelius/github/smoelius/rust-clippy/clippy.toml`: unknown field `foobar`, expected one of
           allow-expect-in-tests              enable-raw-pointer-heuristic-for-send    standard-macro-braces
           allow-unwrap-in-tests              enforced-import-renames                  third-party
           allowed-scripts                    enum-variant-name-threshold              too-large-for-stack
           array-size-threshold               enum-variant-size-threshold              too-many-arguments-threshold
           avoid-breaking-exported-api        literal-representation-threshold         too-many-lines-threshold
           await-holding-invalid-types        max-fn-params-bools                      trivial-copy-size-limit
           blacklisted-names                  max-include-file-size                    type-complexity-threshold
           cargo-ignore-publish               max-struct-bools                         unreadable-literal-lint-fractions
           cognitive-complexity-threshold     max-suggested-slice-pattern-length       upper-case-acronyms-aggressive
           cyclomatic-complexity-threshold    max-trait-bounds                         vec-box-size-threshold
           disallowed-methods                 msrv                                     verbose-bit-mask-threshold
           disallowed-types                   pass-by-value-size-limit                 warn-on-all-wildcard-imports
           doc-valid-idents                   single-char-binding-names-threshold      
       at line 1 column 1

You can test this by (say) adding foobar = 42 to Clippy's root clippy.toml file, and running cargo run --bin cargo-clippy.

Note that, to get the terminal width, this PR adds termize as a dependency to cargo-clippy. However, termize is also how rustc_errors gets the terminal width. So, hopefully, this is not a dealbreaker.

r? @xFrednet

changelog: Enhancements: the "unknown field" error messages for config files now wraps the field names.

[xFrednet]

The output looks very cool ❤️ the dependency should be fine if it's also used by rustc_errors 🙃

This is also worthy of a changelog entry 🙃

[xFrednet]

The output already looks good to me 👍

[xFrednet]

Is there any advantage in getting the width here and storing it in an environment value? This will not be used 99% of the time. Could we move this to the warning code? Having an environment value is usually intended to enable users to configure or read something, but neither applies here.

If there is a reason for this, I'm fine with it 🙃

[smoelius]

I think Cargo is piping rustc's IO, though I haven't been able to figure out precisely where this occurs (in the jobserver crate is my best guess). When I tried to do as you suggested, I got None from termize::dimensions() every time. I even tried at the very start of the driver's main function, but the result was the same.

As I was typing this, I realized that dimensions_stdin should be dimensions in the line you cited, hence the forced push. (dimensions_stdin was a relic from experimenting with this very issue.)

[xFrednet]

Good to know that might also come in handy for a different project 🙃

[xFrednet]

As I was typing this, I realized that dimensions_stdin should be dimensions in the line you cited, hence the forced push. (dimensions_stdin was a relic from experimenting with this very issue.)

Thanks for the hint. GitHub has finally improved their force push information so that it's possible to see the specific changes of a force push. 🥳

[xFrednet]

Looks good to me, thank you for the update!

I've changed the changelog slightly, hope that's okay with you 🙃

@bors r+

[bors]

📌 Commit 5647257 has been approved by xFrednet

[bors]

⌛ Testing commit 5647257 with merge b6ad6fc...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: xFrednet
Pushing b6ad6fc to master...

[hellow554]

This looks like a typical clippy lint: use writeln instead 😁

[smoelius]

Ironically, on lines 422, 426, and 437, I originally had s += .... Then, format_push_string fired, and I changed them to write!.

I don't know why write_with_newline doesn't fire here. But to be honest, I'm kind of glad it doesn't. My aesthetic self kind of prefers the symmetry with lines 426 and 437. 🤷