cargo/lints/rules/
unused_workspace_dependencies.rs

1use std::path::Path;
2
3use annotate_snippets::AnnotationKind;
4use annotate_snippets::Group;
5use annotate_snippets::Level;
6use annotate_snippets::Origin;
7use annotate_snippets::Patch;
8use annotate_snippets::Snippet;
9use cargo_util_schemas::manifest::InheritableDependency;
10use cargo_util_schemas::manifest::TomlToolLints;
11use indexmap::IndexSet;
12
13use crate::CargoResult;
14use crate::GlobalContext;
15use crate::core::MaybePackage;
16use crate::core::Workspace;
17use crate::lints::Lint;
18use crate::lints::LintLevel;
19use crate::lints::SUSPICIOUS;
20use crate::lints::get_key_value_span;
21use crate::lints::rel_cwd_manifest_path;
22
23pub const LINT: Lint = Lint {
24    name: "unused_workspace_dependencies",
25    desc: "unused workspace dependency",
26    primary_group: &SUSPICIOUS,
27    edition_lint_opts: None,
28    feature_gate: None,
29    docs: Some(
30        r#"
31### What it does
32Checks for any entry in `[workspace.dependencies]` that has not been inherited
33
34### Why it is bad
35They can give the false impression that these dependencies are used
36
37### Example
38```toml
39[workspace.dependencies]
40regex = "1"
41
42[dependencies]
43```
44"#,
45    ),
46};
47
48pub fn unused_workspace_dependencies(
49    ws: &Workspace<'_>,
50    maybe_pkg: &MaybePackage,
51    manifest_path: &Path,
52    cargo_lints: &TomlToolLints,
53    error_count: &mut usize,
54    gctx: &GlobalContext,
55) -> CargoResult<()> {
56    let (lint_level, reason) = LINT.level(
57        cargo_lints,
58        maybe_pkg.edition(),
59        maybe_pkg.unstable_features(),
60    );
61    if lint_level == LintLevel::Allow {
62        return Ok(());
63    }
64
65    let workspace_deps: IndexSet<_> = maybe_pkg
66        .original_toml()
67        .and_then(|t| t.workspace.as_ref())
68        .and_then(|w| w.dependencies.as_ref())
69        .iter()
70        .flat_map(|d| d.keys())
71        .collect();
72
73    let mut inherited_deps = IndexSet::new();
74    for member in ws.members() {
75        let Some(original_toml) = member.manifest().original_toml() else {
76            return Ok(());
77        };
78        inherited_deps.extend(
79            original_toml
80                .build_dependencies()
81                .into_iter()
82                .flatten()
83                .filter(|(_, d)| is_inherited(d))
84                .map(|(name, _)| name),
85        );
86        inherited_deps.extend(
87            original_toml
88                .dependencies
89                .iter()
90                .flatten()
91                .filter(|(_, d)| is_inherited(d))
92                .map(|(name, _)| name),
93        );
94        inherited_deps.extend(
95            original_toml
96                .dev_dependencies()
97                .into_iter()
98                .flatten()
99                .filter(|(_, d)| is_inherited(d))
100                .map(|(name, _)| name),
101        );
102        for target in original_toml.target.iter().flat_map(|t| t.values()) {
103            inherited_deps.extend(
104                target
105                    .build_dependencies()
106                    .into_iter()
107                    .flatten()
108                    .filter(|(_, d)| is_inherited(d))
109                    .map(|(name, _)| name),
110            );
111            inherited_deps.extend(
112                target
113                    .dependencies
114                    .iter()
115                    .flatten()
116                    .filter(|(_, d)| is_inherited(d))
117                    .map(|(name, _)| name),
118            );
119            inherited_deps.extend(
120                target
121                    .dev_dependencies()
122                    .into_iter()
123                    .flatten()
124                    .filter(|(_, d)| is_inherited(d))
125                    .map(|(name, _)| name),
126            );
127        }
128    }
129
130    for (i, unused) in workspace_deps.difference(&inherited_deps).enumerate() {
131        let document = maybe_pkg.document();
132        let contents = maybe_pkg.contents();
133        let level = lint_level.to_diagnostic_level();
134        let manifest_path = rel_cwd_manifest_path(manifest_path, gctx);
135        let emitted_source = LINT.emitted_source(lint_level, reason);
136
137        let mut primary = Group::with_title(level.primary_title(LINT.desc));
138        if let Some(document) = document
139            && let Some(contents) = contents
140        {
141            let mut snippet = Snippet::source(contents).path(&manifest_path);
142            if let Some(span) =
143                get_key_value_span(document, &["workspace", "dependencies", unused.as_str()])
144            {
145                snippet = snippet.annotation(AnnotationKind::Primary.span(span.key));
146            }
147            primary = primary.element(snippet);
148        } else {
149            primary = primary.element(Origin::path(&manifest_path));
150        }
151        if i == 0 {
152            primary = primary.element(Level::NOTE.message(emitted_source));
153        }
154        let mut report = vec![primary];
155        if let Some(document) = document
156            && let Some(contents) = contents
157        {
158            let mut help = Group::with_title(
159                Level::HELP.secondary_title("consider removing the unused dependency"),
160            );
161            let mut snippet = Snippet::source(contents).path(&manifest_path);
162            if let Some(span) =
163                get_key_value_span(document, &["workspace", "dependencies", unused.as_str()])
164            {
165                snippet = snippet.patch(Patch::new(span.key.start..span.value.end, ""));
166            }
167            help = help.element(snippet);
168            report.push(help);
169        }
170
171        if lint_level.is_error() {
172            *error_count += 1;
173        }
174        gctx.shell().print_report(&report, lint_level.force())?;
175    }
176
177    Ok(())
178}
179
180fn is_inherited(dep: &InheritableDependency) -> bool {
181    matches!(dep, InheritableDependency::Inherit(_))
182}
cargo/lints/rules/unused_workspace_dependencies.rs

cargo/lints/rules/
unused_workspace_dependencies.rs
