Fixed errors and lack of documentation in mod.rs.

Author: Mason Ray Hanna III

clippy_lints/src/methods/mod.rs

@@ -1,4 +1,3 @@
-mod path_join_correction;
 mod bind_instead_of_map;
 mod bytecount;
 mod bytes_count_to_len;
@@ -69,6 +68,7 @@ mod option_map_unwrap_or;
 mod or_fun_call;
 mod or_then_unwrap;
 mod path_buf_push_overwrite;
+mod path_join_correction;
 mod range_zip_with_len;
 mod repeat_once;
 mod search_is_some;
@@ -3219,21 +3219,23 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    ///
+    /// Checks for initial '/' in an argument to .join on a path.
     /// ### Why is this bad?
-    ///
+    /// .join() calls on paths already attach the '/'.
     /// ### Example
     /// ```rust
     /// // example code where clippy issues a warning
+    /// let path = std::path::Path::new("/bin");
+    /// path.join("/sh");
     /// ```
     /// Use instead:
     /// ```rust
-    /// // example code which does not raise clippy warning
+    /// // path.join("sh");
     /// ```
     #[clippy::version = "1.70.0"]
     pub PATH_JOIN_CORRECTION,
     pedantic,
-    "default lint description"
+    "arg to .join called on a Path contains '/' at the start"
 }
 
 pub struct Methods {
@@ -3678,9 +3680,6 @@ impl Methods {
                     }
 		    else {path_join_correction::check(cx, expr,  join_arg, span);}
                 },
-	        /*("join", [join_arg]) => {
-		    path_join_correction::check(cx, expr,  join_arg, span);
-		},*/
                 ("last", []) | ("skip", [_]) => {
                     if let Some((name2, recv2, args2, _span2, _)) = method_call(recv) {
                         if let ("cloned", []) = (name2, args2) {

clippy_lints/src/methods/path_join_correction.rs

@@ -1,34 +1,28 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use rustc_lint::{LateContext};
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
+use rustc_lint::LateContext;
 use rustc_span::Span;
 
 use super::PATH_JOIN_CORRECTION;
 
-
-pub(super) fn check<'tcx>(
-    cx: &LateContext<'tcx>,
-    expr: &'tcx Expr<'tcx>,
-    join_arg: &'tcx Expr<'tcx>,
-    span: Span,
-) {
-  let applicability = Applicability::MachineApplicable;
-  if_chain!(
-    if let ExprKind::Lit(spanned) = &join_arg.kind;
-    if let LitKind::Str(symbol, _) = spanned.node;
-    if symbol.as_str().starts_with('/');
-    then {
-      span_lint_and_sugg(
-	cx,
-	PATH_JOIN_CORRECTION,
-	span.with_hi(expr.span.hi()),
-	r#"argument in join called on path contains a starting '/'"#,
-	"try removing first '/'",
-	"join(\"your/path/here\")".to_owned(),
-	applicability
-      );
-    }
-  );
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, join_arg: &'tcx Expr<'tcx>, span: Span) {
+    let applicability = Applicability::MachineApplicable;
+    if_chain!(
+      if let ExprKind::Lit(spanned) = &join_arg.kind;
+      if let LitKind::Str(symbol, _) = spanned.node;
+      if symbol.as_str().starts_with('/');
+      then {
+        span_lint_and_sugg(
+      cx,
+      PATH_JOIN_CORRECTION,
+      span.with_hi(expr.span.hi()),
+      r#"argument in join called on path contains a starting '/'"#,
+      "try removing first '/'",
+      "join(\"your/path/here\")".to_owned(),
+      applicability
+        );
+      }
+    );
 }

tests/ui/path_join_correction.fixed

@@ -0,0 +1,15 @@
+// run-rustfix
+#![allow(unused)]
+#![warn(clippy::path_join_correction)]
+
+fn main() {
+    // should be linted
+    let path = std::path::Path::new("/bin");
+    path.join("your/path/here");
+    println!("{}", path.display());
+
+    //should not be linted
+    let path = std::path::Path::new("/bin");
+    path.join("sh");
+    println!("{}", path.display());
+}

tests/ui/path_join_correction.rs

@@ -1,15 +1,15 @@
+// run-rustfix
 #![allow(unused)]
 #![warn(clippy::path_join_correction)]
 
 fn main() {
-  // should be linted
-  let path = std::path::Path::new("/bin");
-  path.join("/sh");
-  println!("{}", path.display());
+    // should be linted
+    let path = std::path::Path::new("/bin");
+    path.join("/sh");
+    println!("{}", path.display());
 
-  //should not be linted
-  let path = std::path::Path::new("/bin");
-  path.join("sh");
-  println!("{}", path.display());
-  
+    //should not be linted
+    let path = std::path::Path::new("/bin");
+    path.join("sh");
+    println!("{}", path.display());
 }

tests/ui/path_join_correction.stderr

@@ -1,8 +1,8 @@
 error: argument in join called on path contains a starting '/'
-  --> $DIR/path_join_correction.rs:7:8
+  --> $DIR/path_join_correction.rs:8:10
    |
-LL |   path.join("/sh");
-   |        ^^^^^^^^^^^ help: try removing first '/': `join("your/path/here")`
+LL |     path.join("/sh");
+   |          ^^^^^^^^^^^ help: try removing first '/': `join("your/path/here")`
    |
    = note: `-D clippy::path-join-correction` implied by `-D warnings`