cargo/diagnostics/rules/
non_snake_case_features.rs

1use std::path::Path;
2
3use cargo_util_schemas::manifest::TomlToolLints;
4use cargo_util_terminal::report::AnnotationKind;
5use cargo_util_terminal::report::Group;
6use cargo_util_terminal::report::Level;
7use cargo_util_terminal::report::Origin;
8use cargo_util_terminal::report::Patch;
9use cargo_util_terminal::report::Snippet;
10use tracing::instrument;
11
12use super::RESTRICTION;
13use crate::CargoResult;
14use crate::GlobalContext;
15use crate::core::Package;
16use crate::diagnostics::Lint;
17use crate::diagnostics::LintLevel;
18use crate::diagnostics::LintLevelSource;
19use crate::diagnostics::get_key_value_span;
20use crate::diagnostics::rel_cwd_manifest_path;
21
22pub static LINT: &Lint = &Lint {
23    name: "non_snake_case_features",
24    desc: "features should have a snake-case name",
25    primary_group: &RESTRICTION,
26    msrv: None,
27    feature_gate: None,
28    docs: Some(
29        r#"
30### What it does
31
32Detect feature names that are not snake-case.
33
34### Why it is bad
35
36Having multiple naming styles within a workspace can be confusing.
37
38### Drawbacks
39
40Users would expect that a feature tightly coupled to a dependency would match the dependency's name.
41
42### Example
43
44```toml
45[features]
46foo-bar = []
47```
48
49Should be written as:
50
51```toml
52[features]
53foo_bar = []
54```
55"#,
56    ),
57};
58
59#[instrument(skip_all)]
60pub fn non_snake_case_features(
61    pkg: &Package,
62    manifest_path: &Path,
63    cargo_lints: &TomlToolLints,
64    error_count: &mut usize,
65    gctx: &GlobalContext,
66) -> CargoResult<()> {
67    let (lint_level, source) = LINT.level(
68        cargo_lints,
69        pkg.rust_version(),
70        pkg.manifest().unstable_features(),
71    );
72
73    if lint_level == LintLevel::Allow {
74        return Ok(());
75    }
76
77    let manifest_path = rel_cwd_manifest_path(manifest_path, gctx);
78
79    lint_package(pkg, &manifest_path, lint_level, source, error_count, gctx)
80}
81
82fn lint_package(
83    pkg: &Package,
84    manifest_path: &str,
85    lint_level: LintLevel,
86    source: LintLevelSource,
87    error_count: &mut usize,
88    gctx: &GlobalContext,
89) -> CargoResult<()> {
90    for original_name in pkg.summary().features().keys() {
91        let original_name = &**original_name;
92        let snake_case = heck::ToSnakeCase::to_snake_case(original_name);
93        if snake_case == original_name {
94            continue;
95        }
96
97        let manifest = pkg.manifest();
98        let document = manifest.document();
99        let contents = manifest.contents();
100        let level = lint_level.to_diagnostic_level();
101        let emitted_source = LINT.emitted_source(lint_level, source);
102
103        let mut primary = Group::with_title(level.primary_title(LINT.desc));
104        if let Some(document) = document
105            && let Some(contents) = contents
106            && let Some(span) = get_key_value_span(document, &["features", original_name])
107        {
108            primary = primary.element(
109                Snippet::source(contents)
110                    .path(manifest_path)
111                    .annotation(AnnotationKind::Primary.span(span.key)),
112            );
113        } else if let Some(document) = document
114            && let Some(contents) = contents
115            && let Some(dep_span) = get_key_value_span(document, &["dependencies", original_name])
116            && let Some(optional_span) =
117                get_key_value_span(document, &["dependencies", original_name, "optional"])
118        {
119            primary = primary.element(
120                Snippet::source(contents)
121                    .path(manifest_path)
122                    .annotation(AnnotationKind::Primary.span(dep_span.key).label("source of feature name"))
123                    .annotation(
124                        AnnotationKind::Context
125                            .span(optional_span.key.start..optional_span.value.end)
126                            .label("cause of feature"),
127                    ),
128            ).element(Level::NOTE.message("see also <https://doc.rust-lang.org/cargo/reference/features.html#optional-dependencies>"));
129        } else {
130            primary = primary.element(Origin::path(manifest_path));
131        }
132        primary = primary.element(Level::NOTE.message(emitted_source));
133        let mut report = vec![primary];
134        if let Some(document) = document
135            && let Some(contents) = contents
136            && let Some(span) = get_key_value_span(document, &["features", original_name])
137        {
138            let mut help = Group::with_title(Level::HELP.secondary_title(
139                "to change the feature name to snake case, convert the `features` key",
140            ));
141            help = help.element(
142                Snippet::source(contents)
143                    .path(manifest_path)
144                    .patch(Patch::new(span.key, snake_case.as_str())),
145            );
146            report.push(help);
147        }
148
149        if lint_level.is_error() {
150            *error_count += 1;
151        }
152        gctx.shell().print_report(&report, lint_level.force())?;
153    }
154
155    Ok(())
156}
cargo/diagnostics/rules/non_snake_case_features.rs

cargo/diagnostics/rules/
non_snake_case_features.rs
