clippy_lints/src/missing_enforced_import_rename.rs

   1 use clippy_utils::{diagnostics::span_lint_and_sugg, source::snippet_opt};
   2
   3 use rustc_data_structures::fx::FxHashMap;
   4 use rustc_errors::Applicability;
   5 use rustc_hir::{def::Res, def_id::DefId, Crate, Item, ItemKind, UseKind};
   6 use rustc_lint::{LateContext, LateLintPass, LintContext};
   7 use rustc_session::{declare_tool_lint, impl_lint_pass};
   8 use rustc_span::Symbol;
   9
  10 use crate::utils::conf::Rename;
  11
  12 declare_clippy_lint! {
  13     /// **What it does:** Checks for imports that do not rename the item as specified
  14     /// in the `enforce-import-renames` config option.
  15     ///
  16     /// **Why is this bad?** Consistency is important, if a project has defined import
  17     /// renames they should be followed. More practically, some item names are too
  18     /// vague outside of their defining scope this can enforce a more meaningful naming.
  19     ///
  20     /// **Known problems:** None
  21     ///
  22     /// **Example:**
  23     ///
  24     /// An example clippy.toml configuration:
  25     /// ```toml
  26     /// # clippy.toml
  27     /// enforced-import-renames = [ { path = "serde_json::Value", rename = "JsonValue" }]
  28     /// ```
  29     ///
  30     /// ```rust,ignore
  31     /// use serde_json::Value;
  32     /// ```
  33     /// Use instead:
  34     /// ```rust,ignore
  35     /// use serde_json::Value as JsonValue;
  36     /// ```
  37     pub MISSING_ENFORCED_IMPORT_RENAMES,
  38     restriction,
  39     "enforce import renames"
  40 }
  41
  42 pub struct ImportRename {
  43     conf_renames: Vec<Rename>,
  44     renames: FxHashMap<DefId, Symbol>,
  45 }
  46
  47 impl ImportRename {
  48     pub fn new(conf_renames: Vec<Rename>) -> Self {
  49         Self {
  50             conf_renames,
  51             renames: FxHashMap::default(),
  52         }
  53     }
  54 }
  55
  56 impl_lint_pass!(ImportRename => [MISSING_ENFORCED_IMPORT_RENAMES]);
  57
  58 impl LateLintPass<'_> for ImportRename {
  59     fn check_crate(&mut self, cx: &LateContext<'_>, _: &Crate<'_>) {
  60         for Rename { path, rename } in &self.conf_renames {
  61             if let Res::Def(_, id) = clippy_utils::path_to_res(cx, &path.split("::").collect::<Vec<_>>()) {
  62                 self.renames.insert(id, Symbol::intern(rename));
  63             }
  64         }
  65     }
  66
  67     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
  68         if_chain! {
  69             if let ItemKind::Use(path, UseKind::Single) = &item.kind;
  70             if let Res::Def(_, id) = path.res;
  71             if let Some(name) = self.renames.get(&id);
  72             // Remove semicolon since it is not present for nested imports
  73             let span_without_semi = cx.sess().source_map().span_until_char(item.span, ';');
  74             if let Some(snip) = snippet_opt(cx, span_without_semi);
  75             if let Some(import) = match snip.split_once(" as ") {
  76                 None => Some(snip.as_str()),
  77                 Some((import, rename)) => {
  78                     if rename.trim() == &*name.as_str() {
  79                         None
  80                     } else {
  81                         Some(import.trim())
  82                     }
  83                 },
  84             };
  85             then {
  86                 span_lint_and_sugg(
  87                     cx,
  88                     MISSING_ENFORCED_IMPORT_RENAMES,
  89                     span_without_semi,
  90                     "this import should be renamed",
  91                     "try",
  92                     format!(
  93                         "{} as {}",
  94                         import,
  95                         name,
  96                     ),
  97                     Applicability::MachineApplicable,
  98                 );
  99             }
 100         }
 101     }
 102 }