clippy_lints/src/wildcard_dependencies.rs

   1 use crate::utils::span_lint;
   2 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
   3 use rustc::{declare_tool_lint, lint_array};
   4 use syntax::{ast::*, source_map::DUMMY_SP};
   5
   6 use cargo_metadata;
   7 use if_chain::if_chain;
   8 use semver;
   9
  10 declare_clippy_lint! {
  11     /// **What it does:** Checks for wildcard dependencies in the `Cargo.toml`.
  12     ///
  13     /// **Why is this bad?** [As the edition guide says](https://rust-lang-nursery.github.io/edition-guide/rust-2018/cargo-and-crates-io/crates-io-disallows-wildcard-dependencies.html),
  14     /// it is highly unlikely that you work with any possible version of your dependency,
  15     /// and wildcard dependencies would cause unnecessary breakage in the ecosystem.
  16     ///
  17     /// **Known problems:** None.
  18     ///
  19     /// **Example:**
  20     ///
  21     /// ```toml
  22     /// [dependencies]
  23     /// regex = "*"
  24     /// ```
  25     pub WILDCARD_DEPENDENCIES,
  26     cargo,
  27     "wildcard dependencies being used"
  28 }
  29
  30 pub struct Pass;
  31
  32 impl LintPass for Pass {
  33     fn get_lints(&self) -> LintArray {
  34         lint_array!(WILDCARD_DEPENDENCIES)
  35     }
  36
  37     fn name(&self) -> &'static str {
  38         "WildcardDependencies"
  39     }
  40 }
  41
  42 impl EarlyLintPass for Pass {
  43     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &Crate) {
  44         let metadata = if let Ok(metadata) = cargo_metadata::MetadataCommand::new().no_deps().exec() {
  45             metadata
  46         } else {
  47             span_lint(cx, WILDCARD_DEPENDENCIES, DUMMY_SP, "could not read cargo metadata");
  48             return;
  49         };
  50
  51         for dep in &metadata.packages[0].dependencies {
  52             // VersionReq::any() does not work
  53             if_chain! {
  54                 if let Ok(wildcard_ver) = semver::VersionReq::parse("*");
  55                 if let Some(ref source) = dep.source;
  56                 if !source.starts_with("git");
  57                 if dep.req == wildcard_ver;
  58                 then {
  59                     span_lint(
  60                         cx,
  61                         WILDCARD_DEPENDENCIES,
  62                         DUMMY_SP,
  63                         &format!("wildcard dependency for `{}`", dep.name),
  64                     );
  65                 }
  66             }
  67         }
  68     }
  69 }