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     #[clippy::version = "1.55.0"]
  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<'_>) {
  60         for Rename { path, rename } in &self.conf_renames {
  61             let segs = path.split("::").collect::<Vec<_>>();
  62             for id in clippy_utils::def_path_def_ids(cx, &segs) {
  63                 self.renames.insert(id, Symbol::intern(rename));
  64             }
  65         }
  66     }
  67
  68     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
  69         if let ItemKind::Use(path, UseKind::Single) = &item.kind {
  70             for &res in &path.res {
  71                 if_chain! {
  72                     if let Res::Def(_, id) = res;
  73                     if let Some(name) = self.renames.get(&id);
  74                     // Remove semicolon since it is not present for nested imports
  75                     let span_without_semi = cx.sess().source_map().span_until_char(item.span, ';');
  76                     if let Some(snip) = snippet_opt(cx, span_without_semi);
  77                     if let Some(import) = match snip.split_once(" as ") {
  78                         None => Some(snip.as_str()),
  79                         Some((import, rename)) => {
  80                             if rename.trim() == name.as_str() {
  81                                 None
  82                             } else {
  83                                 Some(import.trim())
  84                             }
  85                         },
  86                     };
  87                     then {
  88                         span_lint_and_sugg(
  89                             cx,
  90                             MISSING_ENFORCED_IMPORT_RENAMES,
  91                             span_without_semi,
  92                             "this import should be renamed",
  93                             "try",
  94                             format!(
  95                                 "{import} as {name}",
  96                             ),
  97                             Applicability::MachineApplicable,
  98                         );
  99                     }
 100                 }
 101             }
 102         }
 103     }
 104 }