clippy_lints/src/wildcard_dependencies.rs

   1 use crate::utils::span_lint;
   2 use rustc_lint::{EarlyContext, EarlyLintPass};
   3 use rustc_session::{declare_lint_pass, declare_tool_lint};
   4 use rustc_span::source_map::DUMMY_SP;
   5 use syntax::ast::*;
   6
   7 use if_chain::if_chain;
   8
   9 declare_clippy_lint! {
  10     /// **What it does:** Checks for wildcard dependencies in the `Cargo.toml`.
  11     ///
  12     /// **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),
  13     /// it is highly unlikely that you work with any possible version of your dependency,
  14     /// and wildcard dependencies would cause unnecessary breakage in the ecosystem.
  15     ///
  16     /// **Known problems:** None.
  17     ///
  18     /// **Example:**
  19     ///
  20     /// ```toml
  21     /// [dependencies]
  22     /// regex = "*"
  23     /// ```
  24     pub WILDCARD_DEPENDENCIES,
  25     cargo,
  26     "wildcard dependencies being used"
  27 }
  28
  29 declare_lint_pass!(WildcardDependencies => [WILDCARD_DEPENDENCIES]);
  30
  31 impl EarlyLintPass for WildcardDependencies {
  32     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &Crate) {
  33         let metadata = if let Ok(metadata) = cargo_metadata::MetadataCommand::new().no_deps().exec() {
  34             metadata
  35         } else {
  36             span_lint(cx, WILDCARD_DEPENDENCIES, DUMMY_SP, "could not read cargo metadata");
  37             return;
  38         };
  39
  40         for dep in &metadata.packages[0].dependencies {
  41             // VersionReq::any() does not work
  42             if_chain! {
  43                 if let Ok(wildcard_ver) = semver::VersionReq::parse("*");
  44                 if let Some(ref source) = dep.source;
  45                 if !source.starts_with("git");
  46                 if dep.req == wildcard_ver;
  47                 then {
  48                     span_lint(
  49                         cx,
  50                         WILDCARD_DEPENDENCIES,
  51                         DUMMY_SP,
  52                         &format!("wildcard dependency for `{}`", dep.name),
  53                     );
  54                 }
  55             }
  56         }
  57     }
  58 }