cargo/diagnostics/rules/
unused_workspace_dependencies.rs

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

cargo/diagnostics/rules/
unused_workspace_dependencies.rs
