cargo/diagnostics/rules/
unused_workspace_dependencies.rs

1use std::path::Path;
2
3use cargo_util_schemas::manifest::InheritableDependency;
4use cargo_util_schemas::manifest::TomlToolLints;
5use cargo_util_terminal::report::AnnotationKind;
6use cargo_util_terminal::report::Group;
7use cargo_util_terminal::report::Level;
8use cargo_util_terminal::report::Origin;
9use cargo_util_terminal::report::Patch;
10use cargo_util_terminal::report::Snippet;
11use indexmap::IndexSet;
12use tracing::instrument;
13
14use super::SUSPICIOUS;
15use crate::CargoResult;
16use crate::GlobalContext;
17use crate::core::MaybePackage;
18use crate::core::Workspace;
19use crate::diagnostics::DiagnosticStats;
20use crate::diagnostics::Lint;
21use crate::diagnostics::LintLevel;
22use crate::diagnostics::get_key_value_span;
23use crate::diagnostics::rel_cwd_manifest_path;
24
25pub static LINT: &Lint = &Lint {
26    name: "unused_workspace_dependencies",
27    desc: "unused workspace dependency",
28    primary_group: &SUSPICIOUS,
29    msrv: Some(super::CARGO_LINTS_MSRV),
30    feature_gate: None,
31    docs: Some(
32        r#"
33### What it does
34Checks for any entry in `[workspace.dependencies]` that has not been inherited
35
36### Why it is bad
37They can give the false impression that these dependencies are used
38
39### Example
40```toml
41[workspace.dependencies]
42regex = "1"
43
44[dependencies]
45```
46"#,
47    ),
48};
49
50#[instrument(skip_all)]
51pub fn unused_workspace_dependencies(
52    ws: &Workspace<'_>,
53    maybe_pkg: &MaybePackage,
54    manifest_path: &Path,
55    cargo_lints: &TomlToolLints,
56    stats: &mut DiagnosticStats,
57    gctx: &GlobalContext,
58) -> CargoResult<()> {
59    let (lint_level, source) = LINT.level(
60        cargo_lints,
61        ws.lowest_rust_version(),
62        maybe_pkg.unstable_features(),
63    );
64    if lint_level == LintLevel::Allow {
65        return Ok(());
66    }
67
68    let workspace_deps: IndexSet<_> = maybe_pkg
69        .original_toml()
70        .and_then(|t| t.workspace.as_ref())
71        .and_then(|w| w.dependencies.as_ref())
72        .iter()
73        .flat_map(|d| d.keys())
74        .collect();
75
76    let mut inherited_deps = IndexSet::new();
77    for member in ws.members() {
78        let Some(original_toml) = member.manifest().original_toml() else {
79            return Ok(());
80        };
81        inherited_deps.extend(
82            original_toml
83                .build_dependencies()
84                .into_iter()
85                .flatten()
86                .filter(|(_, d)| is_inherited(d))
87                .map(|(name, _)| name),
88        );
89        inherited_deps.extend(
90            original_toml
91                .dependencies
92                .iter()
93                .flatten()
94                .filter(|(_, d)| is_inherited(d))
95                .map(|(name, _)| name),
96        );
97        inherited_deps.extend(
98            original_toml
99                .dev_dependencies()
100                .into_iter()
101                .flatten()
102                .filter(|(_, d)| is_inherited(d))
103                .map(|(name, _)| name),
104        );
105        for target in original_toml.target.iter().flat_map(|t| t.values()) {
106            inherited_deps.extend(
107                target
108                    .build_dependencies()
109                    .into_iter()
110                    .flatten()
111                    .filter(|(_, d)| is_inherited(d))
112                    .map(|(name, _)| name),
113            );
114            inherited_deps.extend(
115                target
116                    .dependencies
117                    .iter()
118                    .flatten()
119                    .filter(|(_, d)| is_inherited(d))
120                    .map(|(name, _)| name),
121            );
122            inherited_deps.extend(
123                target
124                    .dev_dependencies()
125                    .into_iter()
126                    .flatten()
127                    .filter(|(_, d)| is_inherited(d))
128                    .map(|(name, _)| name),
129            );
130        }
131    }
132
133    for (i, unused) in workspace_deps.difference(&inherited_deps).enumerate() {
134        let document = maybe_pkg.document();
135        let contents = maybe_pkg.contents();
136        let level = lint_level.to_diagnostic_level();
137        let manifest_path = rel_cwd_manifest_path(manifest_path, gctx);
138        let emitted_source = LINT.emitted_source(lint_level, source);
139
140        let mut primary = Group::with_title(level.primary_title(LINT.desc));
141        if let Some(document) = document
142            && let Some(contents) = contents
143        {
144            let mut snippet = Snippet::source(contents).path(&manifest_path);
145            if let Some(span) =
146                get_key_value_span(document, &["workspace", "dependencies", unused.as_str()])
147            {
148                snippet = snippet.annotation(AnnotationKind::Primary.span(span.key));
149            }
150            primary = primary.element(snippet);
151        } else {
152            primary = primary.element(Origin::path(&manifest_path));
153        }
154        if i == 0 {
155            primary = primary.element(Level::NOTE.message(emitted_source));
156        }
157        let mut report = vec![primary];
158        if let Some(document) = document
159            && let Some(contents) = contents
160        {
161            let mut help = Group::with_title(
162                Level::HELP.secondary_title("consider removing the unused dependency"),
163            );
164            let mut snippet = Snippet::source(contents).path(&manifest_path);
165            if let Some(span) =
166                get_key_value_span(document, &["workspace", "dependencies", unused.as_str()])
167            {
168                snippet = snippet.patch(Patch::new(span.key.start..span.value.end, ""));
169            }
170            help = help.element(snippet);
171            report.push(help);
172        }
173
174        stats.record_lint(lint_level);
175        gctx.shell().print_report(&report, lint_level.force())?;
176    }
177
178    Ok(())
179}
180
181fn is_inherited(dep: &InheritableDependency) -> bool {
182    matches!(dep, InheritableDependency::Inherit(_))
183}
cargo/diagnostics/rules/unused_workspace_dependencies.rs

cargo/diagnostics/rules/
unused_workspace_dependencies.rs
