fix: create_dir ignores paths in suggestions

Author: profetia

clippy_lints/src/create_dir.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet_with_applicability;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
@@ -38,6 +38,8 @@ impl LateLintPass<'_> for CreateDir {
             && let ExprKind::Path(ref path) = func.kind
             && let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id()
             && cx.tcx.is_diagnostic_item(sym::fs_create_dir, def_id)
+            && let QPath::Resolved(_, path) = path
+            && let Some(last) = path.segments.last()
         {
             span_lint_and_then(
                 cx,
@@ -46,13 +48,17 @@ impl LateLintPass<'_> for CreateDir {
                 "calling `std::fs::create_dir` where there may be a better way",
                 |diag| {
                     let mut app = Applicability::MaybeIncorrect;
+                    let prefix_span = func.span.shrink_to_lo().between(last.ident.span);
+                    let prefix_snippet = if !prefix_span.is_empty() {
+                        snippet_with_applicability(cx, prefix_span, "..", &mut app)
+                    } else {
+                        "std::fs::".into()
+                    };
+                    let args_snippet = snippet_with_applicability(cx, arg.span, "..", &mut app);
                     diag.span_suggestion_verbose(
                         expr.span,
                         "consider calling `std::fs::create_dir_all` instead",
-                        format!(
-                            "create_dir_all({})",
-                            snippet_with_applicability(cx, arg.span, "..", &mut app)
-                        ),
+                        format!("{prefix_snippet}create_dir_all({args_snippet})",),
                         app,
                     );
                 },

tests/ui/create_dir.fixed

@@ -7,12 +7,31 @@ fn create_dir() {}
 
 fn main() {
     // Should be warned
-    create_dir_all("foo");
+    std::fs::create_dir_all("foo");
     //~^ create_dir
-    create_dir_all("bar").unwrap();
+    std::fs::create_dir_all("bar").unwrap();
     //~^ create_dir
 
     // Shouldn't be warned
     create_dir();
     std::fs::create_dir_all("foobar");
 }
+
+mod issue14994 {
+    fn with_no_prefix() {
+        use std::fs::create_dir;
+        std::fs::create_dir_all("some/dir").unwrap();
+        //~^ create_dir
+    }
+
+    fn with_fs_prefix() {
+        use std::fs;
+        fs::create_dir_all("/some/dir").unwrap();
+        //~^ create_dir
+    }
+
+    fn with_full_prefix() {
+        std::fs::create_dir_all("/some/dir").unwrap();
+        //~^ create_dir
+    }
+}

tests/ui/create_dir.rs

@@ -16,3 +16,22 @@ fn main() {
     create_dir();
     std::fs::create_dir_all("foobar");
 }
+
+mod issue14994 {
+    fn with_no_prefix() {
+        use std::fs::create_dir;
+        create_dir("some/dir").unwrap();
+        //~^ create_dir
+    }
+
+    fn with_fs_prefix() {
+        use std::fs;
+        fs::create_dir("/some/dir").unwrap();
+        //~^ create_dir
+    }
+
+    fn with_full_prefix() {
+        std::fs::create_dir("/some/dir").unwrap();
+        //~^ create_dir
+    }
+}

tests/ui/create_dir.stderr

@@ -8,9 +8,8 @@ LL |     std::fs::create_dir("foo");
    = help: to override `-D warnings` add `#[allow(clippy::create_dir)]`
 help: consider calling `std::fs::create_dir_all` instead
    |
-LL -     std::fs::create_dir("foo");
-LL +     create_dir_all("foo");
-   |
+LL |     std::fs::create_dir_all("foo");
+   |                        ++++
 
 error: calling `std::fs::create_dir` where there may be a better way
   --> tests/ui/create_dir.rs:12:5
@@ -20,9 +19,42 @@ LL |     std::fs::create_dir("bar").unwrap();
    |
 help: consider calling `std::fs::create_dir_all` instead
    |
-LL -     std::fs::create_dir("bar").unwrap();
-LL +     create_dir_all("bar").unwrap();
+LL |     std::fs::create_dir_all("bar").unwrap();
+   |                        ++++
+
+error: calling `std::fs::create_dir` where there may be a better way
+  --> tests/ui/create_dir.rs:23:9
+   |
+LL |         create_dir("some/dir").unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider calling `std::fs::create_dir_all` instead
+   |
+LL -         create_dir("some/dir").unwrap();
+LL +         std::fs::create_dir_all("some/dir").unwrap();
+   |
+
+error: calling `std::fs::create_dir` where there may be a better way
+  --> tests/ui/create_dir.rs:29:9
+   |
+LL |         fs::create_dir("/some/dir").unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider calling `std::fs::create_dir_all` instead
+   |
+LL |         fs::create_dir_all("/some/dir").unwrap();
+   |                       ++++
+
+error: calling `std::fs::create_dir` where there may be a better way
+  --> tests/ui/create_dir.rs:34:9
+   |
+LL |         std::fs::create_dir("/some/dir").unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: consider calling `std::fs::create_dir_all` instead
    |
+LL |         std::fs::create_dir_all("/some/dir").unwrap();
+   |                            ++++
 
-error: aborting due to 2 previous errors
+error: aborting due to 5 previous errors