clippy_lints/src/wildcard_dependencies.rs

   1 // Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution.
   3 //
   4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   7 // option. This file may not be copied, modified, or distributed
   8 // except according to those terms.
   9
  10 use crate::utils::span_lint;
  11 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
  12 use rustc::{declare_tool_lint, lint_array};
  13 use syntax::{ast::*, source_map::DUMMY_SP};
  14
  15 use cargo_metadata;
  16 use if_chain::if_chain;
  17 use semver;
  18
  19 /// **What it does:** Checks for wildcard dependencies in the `Cargo.toml`.
  20 ///
  21 /// **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),
  22 /// it is highly unlikely that you work with any possible version of your dependency,
  23 /// and wildcard dependencies would cause unnecessary breakage in the ecosystem.
  24 ///
  25 /// **Known problems:** None.
  26 ///
  27 /// **Example:**
  28 ///
  29 /// ```toml
  30 /// [dependencies]
  31 /// regex = "*"
  32 /// ```
  33 declare_clippy_lint! {
  34     pub WILDCARD_DEPENDENCIES,
  35     cargo,
  36     "wildcard dependencies being used"
  37 }
  38
  39 pub struct Pass;
  40
  41 impl LintPass for Pass {
  42     fn get_lints(&self) -> LintArray {
  43         lint_array!(WILDCARD_DEPENDENCIES)
  44     }
  45 }
  46
  47 impl EarlyLintPass for Pass {
  48     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &Crate) {
  49         let metadata = if let Ok(metadata) = cargo_metadata::metadata(None) {
  50             metadata
  51         } else {
  52             span_lint(cx, WILDCARD_DEPENDENCIES, DUMMY_SP, "could not read cargo metadata");
  53             return;
  54         };
  55
  56         for dep in &metadata.packages[0].dependencies {
  57             // VersionReq::any() does not work
  58             if_chain! {
  59                 if let Ok(wildcard_ver) = semver::VersionReq::parse("*");
  60                 if let Some(ref source) = dep.source;
  61                 if !source.starts_with("git");
  62                 if dep.req == wildcard_ver;
  63                 then {
  64                     span_lint(
  65                         cx,
  66                         WILDCARD_DEPENDENCIES,
  67                         DUMMY_SP,
  68                         &format!("wildcard dependency for `{}`", dep.name),
  69                     );
  70                 }
  71             }
  72         }
  73     }
  74 }