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