Add import_rename lint, this adds a field on the Conf struct

CHANGELOG.md

@@ -2432,6 +2432,7 @@ Released 2018-09-13
 [`implicit_hasher`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_hasher
 [`implicit_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_return
 [`implicit_saturating_sub`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_sub
+[`import_rename`]: https://rust-lang.github.io/rust-clippy/master/index.html#import_rename
 [`imprecise_flops`]: https://rust-lang.github.io/rust-clippy/master/index.html#imprecise_flops
 [`inconsistent_digit_grouping`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_digit_grouping
 [`inconsistent_struct_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_struct_constructor

clippy_lints/src/import_rename.rs

@@ -0,0 +1,97 @@
+use clippy_utils::{diagnostics::span_lint_and_sugg, source::snippet_opt};
+
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir::{def::Res, Item, ItemKind, UseKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Symbol;
+
+declare_clippy_lint! {
+    /// **What it does:** Checks that any import matching `import_renames` is renamed.
+    ///
+    /// **Why is this bad?** This is purely about consistency, it is not bad.
+    ///
+    /// **Known problems:** Any import must use the original fully qualified path.
+    ///
+    /// For example, if you want to rename `serde_json::Value`, your clippy.toml
+    /// configuration would look like
+    /// `import-renames = [ { path: "serde_json::value::Value", rename = "JsonValue" }]` and not
+    /// `import-renames = [ { path: "serde_json::Value", rename = "JsonValue" }]` as you might expect.
+    ///
+    ///
+    /// **Example:**
+    ///
+    /// ```rust,ignore
+    /// use serde_json::Value;
+    /// ```
+    /// Use instead:
+    /// ```rust,ignore
+    /// use serde_json::Value as JsonValue;
+    /// ```
+    pub IMPORT_RENAME,
+    restriction,
+    "enforce import renames"
+}
+
+pub struct ImportRename {
+    imports: FxHashSet<(Vec<Symbol>, Symbol)>,
+}
+
+impl ImportRename {
+    pub fn new(imports: &FxHashSet<(String, String)>) -> Self {
+        Self {
+            imports: imports
+                .iter()
+                .map(|(orig, rename)| {
+                    (
+                        orig.split("::").map(|seg| Symbol::intern(seg)).collect::<Vec<_>>(),
+                        Symbol::intern(rename),
+                    )
+                })
+                .collect(),
+        }
+    }
+}
+
+impl_lint_pass!(ImportRename => [IMPORT_RENAME]);
+
+impl LateLintPass<'_> for ImportRename {
+    fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+        if_chain! {
+            if let ItemKind::Use(path, UseKind::Single) = &item.kind;
+            if let Res::Def(_, id) = path.res;
+            if let Some(snip) = snippet_opt(cx, item.span);
+            let use_path = cx.get_def_path(id);
+            if let Some((_, name)) = self.imports.iter().find(|(path, _)| path == &use_path);
+
+            // TODO: alternatively we could use the def_path_str() instead of the full path which would somewhat fix the
+            // problem of having to use fully qualified paths... although then nested imports kinda breaks down
+            //
+            // let orig_import = cx.tcx.def_path_str(id)
+            //   .map(|seg| Symbol::intern(seg)).collect::<Vec<_>>();
+            // if let Some((_, name)) = self.imports.iter().find(|(path, _)| {
+            //     path == &orig_import
+            // });
+
+            // Remove semicolon since it is not present for nested imports
+            if !snip.replace(";", "").ends_with(&format!("{}", name));
+            then {
+                span_lint_and_sugg(
+                    cx,
+                    IMPORT_RENAME,
+                    item.span,
+                    "this import should be renamed",
+                    "try",
+                    format!(
+                        "{} as {}{}",
+                        snip.split_whitespace().take(2).collect::<Vec<_>>().join(" "),
+                        name,
+                        if snip.ends_with(';') { ";" } else { "" },
+                    ),
+                    Applicability::MachineApplicable,
+                );
+            }
+        }
+    }
+}

clippy_lints/src/lib.rs

@@ -225,6 +225,7 @@ mod if_then_some_else_none;
 mod implicit_hasher;
 mod implicit_return;
 mod implicit_saturating_sub;
+mod import_rename;
 mod inconsistent_struct_constructor;
 mod indexing_slicing;
 mod infinite_iter;
@@ -646,6 +647,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         implicit_hasher::IMPLICIT_HASHER,
         implicit_return::IMPLICIT_RETURN,
         implicit_saturating_sub::IMPLICIT_SATURATING_SUB,
+        import_rename::IMPORT_RENAME,
         inconsistent_struct_constructor::INCONSISTENT_STRUCT_CONSTRUCTOR,
         indexing_slicing::INDEXING_SLICING,
         indexing_slicing::OUT_OF_BOUNDS_INDEXING,
@@ -994,6 +996,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(float_literal::LOSSY_FLOAT_LITERAL),
         LintId::of(if_then_some_else_none::IF_THEN_SOME_ELSE_NONE),
         LintId::of(implicit_return::IMPLICIT_RETURN),
+        LintId::of(import_rename::IMPORT_RENAME),
         LintId::of(indexing_slicing::INDEXING_SLICING),
         LintId::of(inherent_impl::MULTIPLE_INHERENT_IMPL),
         LintId::of(integer_division::INTEGER_DIVISION),
@@ -2060,6 +2063,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(move || box if_then_some_else_none::IfThenSomeElseNone::new(msrv));
     store.register_early_pass(|| box bool_assert_comparison::BoolAssertComparison);
     store.register_late_pass(|| box unused_async::UnusedAsync);
+    let renames = conf.import_renames.iter().map(|rn| (rn.path.clone(), rn.rename.clone())).collect::<FxHashSet<_>>();
+    store.register_late_pass(move || box import_rename::ImportRename::new(&renames));
 
 }
 

clippy_lints/src/utils/conf.rs

@@ -8,6 +8,13 @@ use std::error::Error;
 use std::path::{Path, PathBuf};
 use std::{env, fmt, fs, io};
 
+/// Holds information used by `IMPORT_RENAME` lint.
+#[derive(Debug, Default, Deserialize)]
+pub struct Rename {
+    pub path: String,
+    pub rename: String,
+}
+
 /// Conf with parse errors
 #[derive(Default)]
 pub struct TryConf {
@@ -196,6 +203,8 @@ define_Conf! {
     (upper_case_acronyms_aggressive: bool = false),
     /// Lint: _CARGO_COMMON_METADATA. For internal testing only, ignores the current `publish` settings in the Cargo manifest.
     (cargo_ignore_publish: bool = false),
+    /// Lint: IMPORT_RENAMES. The list of imports to always rename, a fully qualified path followed by the rename.
+    (import_renames: Vec<crate::utils::conf::Rename> = Vec::new()),
 }
 
 /// Search for the configuration file.

tests/ui-toml/toml_import_rename/clippy.toml

@@ -0,0 +1,7 @@
+import-renames = [
+    { path = "syn::path::Path", rename = "SynPath" },
+    { path = "serde::de::Deserializer", rename = "SomethingElse" },
+    { path = "serde::ser::Serializer", rename = "DarkTower" },
+    { path = "alloc::collections::btree::map::BTreeMap", rename = "Map" },
+    { path = "regex::bytes", rename = "foo" },
+]

tests/ui-toml/toml_import_rename/conf_import_rename.rs

@@ -0,0 +1,14 @@
+#![allow(unused_imports, dead_code)]
+#![warn(clippy::import_rename)]
+
+extern crate regex;
+extern crate serde;
+extern crate syn;
+
+use regex::bytes as xegersetyb;
+use serde::{de::Deserializer as WrongRename, ser::Serializer as DarkTower};
+use syn::Path as SynPath;
+
+fn main() {
+    use std::collections::BTreeMap as OopsWrongRename;
+}

tests/ui-toml/toml_import_rename/conf_import_rename.stderr

@@ -0,0 +1,22 @@
+error: this import should be renamed
+  --> $DIR/conf_import_rename.rs:8:1
+   |
+LL | use regex::bytes as xegersetyb;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `use regex::bytes as foo;`
+   |
+   = note: `-D clippy::import-rename` implied by `-D warnings`
+
+error: this import should be renamed
+  --> $DIR/conf_import_rename.rs:9:13
+   |
+LL | use serde::{de::Deserializer as WrongRename, ser::Serializer as DarkTower};
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `de::Deserializer as as SomethingElse`
+
+error: this import should be renamed
+  --> $DIR/conf_import_rename.rs:13:5
+   |
+LL |     use std::collections::BTreeMap as OopsWrongRename;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `use std::collections::BTreeMap as Map;`
+
+error: aborting due to 3 previous errors
+

tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr

@@ -1,4 +1,4 @@
-error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `avoid-breaking-exported-api`, `msrv`, `blacklisted-names`, `cognitive-complexity-threshold`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `trivial-copy-size-limit`, `pass-by-value-size-limit`, `too-many-lines-threshold`, `array-size-threshold`, `vec-box-size-threshold`, `max-trait-bounds`, `max-struct-bools`, `max-fn-params-bools`, `warn-on-all-wildcard-imports`, `disallowed-methods`, `unreadable-literal-lint-fractions`, `upper-case-acronyms-aggressive`, `cargo-ignore-publish`, `third-party` at line 5 column 1
+error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `avoid-breaking-exported-api`, `msrv`, `blacklisted-names`, `cognitive-complexity-threshold`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `trivial-copy-size-limit`, `pass-by-value-size-limit`, `too-many-lines-threshold`, `array-size-threshold`, `vec-box-size-threshold`, `max-trait-bounds`, `max-struct-bools`, `max-fn-params-bools`, `warn-on-all-wildcard-imports`, `disallowed-methods`, `unreadable-literal-lint-fractions`, `upper-case-acronyms-aggressive`, `cargo-ignore-publish`, `import-renames`, `third-party` at line 5 column 1
 
 error: aborting due to previous error