Destructure args in methods module

Author: camsteffen

clippy_lints/src/methods/bind_instead_of_map.rs

@@ -80,7 +80,7 @@ pub(crate) trait BindInsteadOfMap {
     fn lint_closure_autofixable(
         cx: &LateContext<'_>,
         expr: &hir::Expr<'_>,
-        args: &[hir::Expr<'_>],
+        recv: &hir::Expr<'_>,
         closure_expr: &hir::Expr<'_>,
         closure_args_span: Span,
     ) -> bool {
@@ -103,7 +103,7 @@ pub(crate) trait BindInsteadOfMap {
                 };
 
                 let closure_args_snip = snippet(cx, closure_args_span, "..");
-                let option_snip = snippet(cx, args[0].span, "..");
+                let option_snip = snippet(cx, recv.span, "..");
                 let note = format!("{}.{}({} {})", option_snip, Self::GOOD_METHOD_NAME, closure_args_snip, some_inner_snip);
                 span_lint_and_sugg(
                     cx,
@@ -158,17 +158,17 @@ pub(crate) trait BindInsteadOfMap {
     }
 
     /// Lint use of `_.and_then(|x| Some(y))` for `Option`s
-    fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) -> bool {
-        if !match_type(cx, cx.typeck_results().expr_ty(&args[0]), Self::TYPE_QPATH) {
+    fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) -> bool {
+        if !match_type(cx, cx.typeck_results().expr_ty(recv), Self::TYPE_QPATH) {
             return false;
         }
 
-        match args[1].kind {
+        match arg.kind {
             hir::ExprKind::Closure(_, _, body_id, closure_args_span, _) => {
                 let closure_body = cx.tcx.hir().body(body_id);
                 let closure_expr = remove_blocks(&closure_body.value);
 
-                if Self::lint_closure_autofixable(cx, expr, args, closure_expr, closure_args_span) {
+                if Self::lint_closure_autofixable(cx, expr, recv, closure_expr, closure_args_span) {
                     true
                 } else {
                     Self::lint_closure(cx, expr, closure_expr)
@@ -182,7 +182,7 @@ pub(crate) trait BindInsteadOfMap {
                     expr.span,
                     Self::no_op_msg().as_ref(),
                     "use the expression directly",
-                    snippet(cx, args[0].span, "..").into(),
+                    snippet(cx, recv.span, "..").into(),
                     Applicability::MachineApplicable,
                 );
                 true

clippy_lints/src/methods/bytes_nth.rs

@@ -3,16 +3,15 @@ use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::is_type_diagnostic_item;
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::Expr;
 use rustc_lint::LateContext;
 use rustc_span::sym;
 
 use super::BYTES_NTH;
 
-pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>]) {
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, recv: &'tcx Expr<'tcx>, n_arg: &'tcx Expr<'tcx>) {
     if_chain! {
-        if let ExprKind::MethodCall(_, _, ref args, _) = expr.kind;
-        let ty = cx.typeck_results().expr_ty(&iter_args[0]).peel_refs();
+        let ty = cx.typeck_results().expr_ty(recv).peel_refs();
         let caller_type = if is_type_diagnostic_item(cx, ty, sym::string_type) {
             Some("String")
         } else if ty.is_str() {
@@ -31,8 +30,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'
                 "try",
                 format!(
                     "{}.as_bytes().get({})",
-                    snippet_with_applicability(cx, iter_args[0].span, "..", &mut applicability),
-                    snippet_with_applicability(cx, args[1].span, "..", &mut applicability)
+                    snippet_with_applicability(cx, recv.span, "..", &mut applicability),
+                    snippet_with_applicability(cx, n_arg.span, "..", &mut applicability)
                 ),
                 applicability,
             );

clippy_lints/src/methods/expect_used.rs

@@ -7,8 +7,8 @@ use rustc_span::sym;
 use super::EXPECT_USED;
 
 /// lint use of `expect()` for `Option`s and `Result`s
-pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, expect_args: &[hir::Expr<'_>]) {
-    let obj_ty = cx.typeck_results().expr_ty(&expect_args[0]).peel_refs();
+pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
+    let obj_ty = cx.typeck_results().expr_ty(recv).peel_refs();
 
     let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) {
         Some((EXPECT_USED, "an Option", "None"))

clippy_lints/src/methods/filetype_is_file.rs

@@ -8,8 +8,8 @@ use rustc_span::source_map::Span;
 
 use super::FILETYPE_IS_FILE;
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
-    let ty = cx.typeck_results().expr_ty(&args[0]);
+pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
+    let ty = cx.typeck_results().expr_ty(recv);
 
     if !match_type(cx, ty, &paths::FILE_TYPE) {
         return;

clippy_lints/src/methods/filter_map.rs

@@ -7,18 +7,23 @@ use rustc_hir as hir;
 use rustc_hir::{Expr, ExprKind, PatKind, UnOp};
 use rustc_lint::LateContext;
 use rustc_middle::ty::TyS;
-use rustc_span::symbol::sym;
+use rustc_span::{sym, Span};
 
 use super::MANUAL_FILTER_MAP;
 use super::MANUAL_FIND_MAP;
 
 /// lint use of `filter().map()` or `find().map()` for `Iterators`
-pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_find: bool) {
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &hir::Expr<'_>,
+    filter_arg: &hir::Expr<'_>,
+    filter_span: Span,
+    map_recv: &hir::Expr<'_>,
+    map_arg: &hir::Expr<'_>,
+    is_find: bool,
+) {
     if_chain! {
-        if let ExprKind::MethodCall(_, _, [map_recv, map_arg], map_span) = expr.kind;
-        if let ExprKind::MethodCall(_, _, [_, filter_arg], filter_span) = map_recv.kind;
         if is_trait_method(cx, map_recv, sym::Iterator);
-
         // filter(|x| ...is_some())...
         if let ExprKind::Closure(_, _, filter_body_id, ..) = filter_arg.kind;
         let filter_body = cx.tcx.hir().body(filter_body_id);
@@ -71,7 +76,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_
         };
         if SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, map_arg);
         then {
-            let span = filter_span.to(map_span);
+            let span = filter_span.with_hi(expr.span.hi());
             let (filter_name, lint) = if is_find {
                 ("find", MANUAL_FIND_MAP)
             } else {

clippy_lints/src/methods/filter_map_identity.rs

@@ -8,15 +8,8 @@ use rustc_span::{source_map::Span, sym};
 
 use super::FILTER_MAP_IDENTITY;
 
-pub(super) fn check(
-    cx: &LateContext<'_>,
-    expr: &hir::Expr<'_>,
-    filter_map_args: &[hir::Expr<'_>],
-    filter_map_span: Span,
-) {
+pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, filter_map_arg: &hir::Expr<'_>, filter_map_span: Span) {
     if is_trait_method(cx, expr, sym::Iterator) {
-        let arg_node = &filter_map_args[1].kind;
-
         let apply_lint = |message: &str| {
             span_lint_and_sugg(
                 cx,
@@ -30,8 +23,8 @@ pub(super) fn check(
         };
 
         if_chain! {
-            if let hir::ExprKind::Closure(_, _, body_id, _, _) = arg_node;
-            let body = cx.tcx.hir().body(*body_id);
+            if let hir::ExprKind::Closure(_, _, body_id, _, _) = filter_map_arg.kind;
+            let body = cx.tcx.hir().body(body_id);
 
             if let hir::PatKind::Binding(_, binding_id, ..) = body.params[0].pat.kind;
             if path_to_local_id(&body.value, binding_id);
@@ -41,7 +34,7 @@ pub(super) fn check(
         }
 
         if_chain! {
-            if let hir::ExprKind::Path(ref qpath) = arg_node;
+            if let hir::ExprKind::Path(ref qpath) = filter_map_arg.kind;
 
             if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY);
 

clippy_lints/src/methods/filter_map_next.rs

@@ -14,7 +14,8 @@ const FILTER_MAP_NEXT_MSRV: RustcVersion = RustcVersion::new(1, 30, 0);
 pub(super) fn check<'tcx>(
     cx: &LateContext<'tcx>,
     expr: &'tcx hir::Expr<'_>,
-    filter_args: &'tcx [hir::Expr<'_>],
+    recv: &'tcx hir::Expr<'_>,
+    arg: &'tcx hir::Expr<'_>,
     msrv: Option<&RustcVersion>,
 ) {
     if is_trait_method(cx, expr, sym::Iterator) {
@@ -24,9 +25,9 @@ pub(super) fn check<'tcx>(
 
         let msg = "called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling \
                    `.find_map(..)` instead";
-        let filter_snippet = snippet(cx, filter_args[1].span, "..");
+        let filter_snippet = snippet(cx, arg.span, "..");
         if filter_snippet.lines().count() <= 1 {
-            let iter_snippet = snippet(cx, filter_args[0].span, "..");
+            let iter_snippet = snippet(cx, recv.span, "..");
             span_lint_and_sugg(
                 cx,
                 FILTER_MAP_NEXT,

clippy_lints/src/methods/filter_next.rs

@@ -9,14 +9,19 @@ use rustc_span::sym;
 use super::FILTER_NEXT;
 
 /// lint use of `filter().next()` for `Iterators`
-pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) {
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &'tcx hir::Expr<'_>,
+    recv: &'tcx hir::Expr<'_>,
+    filter_arg: &'tcx hir::Expr<'_>,
+) {
     // lint if caller of `.filter().next()` is an Iterator
     if is_trait_method(cx, expr, sym::Iterator) {
         let msg = "called `filter(..).next()` on an `Iterator`. This is more succinctly expressed by calling \
                    `.find(..)` instead";
-        let filter_snippet = snippet(cx, filter_args[1].span, "..");
+        let filter_snippet = snippet(cx, filter_arg.span, "..");
         if filter_snippet.lines().count() <= 1 {
-            let iter_snippet = snippet(cx, filter_args[0].span, "..");
+            let iter_snippet = snippet(cx, recv.span, "..");
             // add note if not multi-line
             span_lint_and_sugg(
                 cx,

clippy_lints/src/methods/flat_map_identity.rs

@@ -12,11 +12,11 @@ use super::FLAT_MAP_IDENTITY;
 pub(super) fn check<'tcx>(
     cx: &LateContext<'tcx>,
     expr: &'tcx hir::Expr<'_>,
-    flat_map_args: &'tcx [hir::Expr<'_>],
+    flat_map_arg: &'tcx hir::Expr<'_>,
     flat_map_span: Span,
 ) {
     if is_trait_method(cx, expr, sym::Iterator) {
-        let arg_node = &flat_map_args[1].kind;
+        let arg_node = &flat_map_arg.kind;
 
         let apply_lint = |message: &str| {
             span_lint_and_sugg(

clippy_lints/src/methods/get_unwrap.rs

@@ -11,18 +11,20 @@ use rustc_span::sym;
 
 use super::GET_UNWRAP;
 
-pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args: &'tcx [hir::Expr<'_>], is_mut: bool) {
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &hir::Expr<'_>,
+    recv: &'tcx hir::Expr<'tcx>,
+    get_arg: &'tcx hir::Expr<'_>,
+    is_mut: bool,
+) {
     // Note: we don't want to lint `get_mut().unwrap` for `HashMap` or `BTreeMap`,
     // because they do not implement `IndexMut`
     let mut applicability = Applicability::MachineApplicable;
-    let expr_ty = cx.typeck_results().expr_ty(&get_args[0]);
-    let get_args_str = if get_args.len() > 1 {
-        snippet_with_applicability(cx, get_args[1].span, "..", &mut applicability)
-    } else {
-        return; // not linting on a .get().unwrap() chain or variant
-    };
+    let expr_ty = cx.typeck_results().expr_ty(recv);
+    let get_args_str = snippet_with_applicability(cx, get_arg.span, "..", &mut applicability);
     let mut needs_ref;
-    let caller_type = if derefs_to_slice(cx, &get_args[0], expr_ty).is_some() {
+    let caller_type = if derefs_to_slice(cx, recv, expr_ty).is_some() {
         needs_ref = get_args_str.parse::<usize>().is_ok();
         "slice"
     } else if is_type_diagnostic_item(cx, expr_ty, sym::vec_type) {
@@ -77,7 +79,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args
         format!(
             "{}{}[{}]",
             borrow_str,
-            snippet_with_applicability(cx, get_args[0].span, "..", &mut applicability),
+            snippet_with_applicability(cx, recv.span, "..", &mut applicability),
             get_args_str
         ),
         applicability,