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 /// **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 declare_clippy_lint! {
  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
  38 impl EarlyLintPass for Pass {
  39     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &Crate) {
  40         let metadata = if let Ok(metadata) = cargo_metadata::metadata(None) {
  41             metadata
  42         } else {
  43             span_lint(cx, WILDCARD_DEPENDENCIES, DUMMY_SP, "could not read cargo metadata");
  44             return;
  45         };
  46
  47         for dep in &metadata.packages[0].dependencies {
  48             // VersionReq::any() does not work
  49             if_chain! {
  50                 if let Ok(wildcard_ver) = semver::VersionReq::parse("*");
  51                 if let Some(ref source) = dep.source;
  52                 if !source.starts_with("git");
  53                 if dep.req == wildcard_ver;
  54                 then {
  55                     span_lint(
  56                         cx,
  57                         WILDCARD_DEPENDENCIES,
  58                         DUMMY_SP,
  59                         &format!("wildcard dependency for `{}`", dep.name),
  60                     );
  61                 }
  62             }
  63         }
  64     }
  65 }