Auto merge of #8802 - smoelius:allow-expect-unwrap-in-tests, r=llogiq

Optionally allow `expect` and `unwrap` in tests

This addresses #1015, except it makes the new behavior optional.

The reason for the msrv-related changes is as follows.

Rather than expand `check_methods` list of arguments, it seemed easier to make `check_methods` a method of `Methods`, so that `check_methods` could access `Methods`' fields.

`check_methods` had an `msrv` parameter, which I consequently made a field of `Methods`. But, to avoid adding a lifetime parameter to `Methods`, I made the field type `Option<RustcVersion>` instead of the parameter's existing type, `Option<&RustcVersion>`. This seemed sensible since `RustcVersion` implements `Copy`. But this broke a lot of code that expected an `Option<&RustcVersion>` or `&Option<RustcVersion>`. I changed all of those occurrences to `Option<RustcVersion>`. IMHO, the code is better as a result of these changes, though.

The msrv-related changes are in their own commit to (hopefully) ease review.

Closes #1015

changelog: optionally allow `expect` and `unwrap` in tests

r? `@llogiq`

clippy_lints/src/approx_const.rs

@@ -87,9 +87,7 @@ impl ApproxConstant {
         let s = s.as_str();
         if s.parse::<f64>().is_ok() {
             for &(constant, name, min_digits, msrv) in &KNOWN_CONSTS {
-                if is_approx_const(constant, s, min_digits)
-                    && msrv.as_ref().map_or(true, |msrv| meets_msrv(self.msrv.as_ref(), msrv))
-                {
+                if is_approx_const(constant, s, min_digits) && msrv.map_or(true, |msrv| meets_msrv(self.msrv, msrv)) {
                     span_lint_and_help(
                         cx,
                         APPROX_CONSTANT,

clippy_lints/src/attrs.rs

@@ -613,7 +613,7 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::It
 
 fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: Option<RustcVersion>) {
     if_chain! {
-        if meets_msrv(msrv.as_ref(), &msrvs::TOOL_ATTRIBUTES);
+        if meets_msrv(msrv, msrvs::TOOL_ATTRIBUTES);
         // check cfg_attr
         if attr.has_name(sym::cfg_attr);
         if let Some(items) = attr.meta_item_list();

clippy_lints/src/borrow_as_ptr.rs

@@ -57,7 +57,7 @@ impl BorrowAsPtr {
 
 impl<'tcx> LateLintPass<'tcx> for BorrowAsPtr {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::BORROW_AS_PTR) {
+        if !meets_msrv(self.msrv, msrvs::BORROW_AS_PTR) {
             return;
         }
 

clippy_lints/src/casts/cast_abs_to_unsigned.rs

@@ -16,10 +16,10 @@ pub(super) fn check(
     cast_expr: &Expr<'_>,
     cast_from: Ty<'_>,
     cast_to: Ty<'_>,
-    msrv: &Option<RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) {
     if_chain! {
-        if meets_msrv(msrv.as_ref(), &msrvs::UNSIGNED_ABS);
+        if meets_msrv(msrv, msrvs::UNSIGNED_ABS);
         if cast_from.is_integral();
         if cast_to.is_integral();
         if cast_from.is_signed();

clippy_lints/src/casts/cast_lossless.rs

@@ -16,7 +16,7 @@ pub(super) fn check(
     cast_op: &Expr<'_>,
     cast_from: Ty<'_>,
     cast_to: Ty<'_>,
-    msrv: &Option<RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) {
     if !should_lint(cx, expr, cast_from, cast_to, msrv) {
         return;
@@ -68,7 +68,7 @@ fn should_lint(
     expr: &Expr<'_>,
     cast_from: Ty<'_>,
     cast_to: Ty<'_>,
-    msrv: &Option<RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) -> bool {
     // Do not suggest using From in consts/statics until it is valid to do so (see #2267).
     if in_constant(cx, expr.hir_id) {
@@ -95,7 +95,7 @@ fn should_lint(
             };
             !is_isize_or_usize(cast_from) && from_nbits < to_nbits
         },
-        (false, true) if matches!(cast_from.kind(), ty::Bool) && meets_msrv(msrv.as_ref(), &msrvs::FROM_BOOL) => true,
+        (false, true) if matches!(cast_from.kind(), ty::Bool) && meets_msrv(msrv, msrvs::FROM_BOOL) => true,
         (_, _) => {
             matches!(cast_from.kind(), ty::Float(FloatTy::F32)) && matches!(cast_to.kind(), ty::Float(FloatTy::F64))
         },

clippy_lints/src/casts/cast_slice_different_sizes.rs

@@ -8,9 +8,9 @@ use rustc_semver::RustcVersion;
 
 use super::CAST_SLICE_DIFFERENT_SIZES;
 
-pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: &Option<RustcVersion>) {
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: Option<RustcVersion>) {
     // suggestion is invalid if `ptr::slice_from_raw_parts` does not exist
-    if !meets_msrv(msrv.as_ref(), &msrvs::PTR_SLICE_RAW_PARTS) {
+    if !meets_msrv(msrv, msrvs::PTR_SLICE_RAW_PARTS) {
         return;
     }
 

clippy_lints/src/casts/mod.rs

@@ -532,7 +532,7 @@ impl_lint_pass!(Casts => [
 impl<'tcx> LateLintPass<'tcx> for Casts {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if !in_external_macro(cx.sess(), expr.span) {
-            ptr_as_ptr::check(cx, expr, &self.msrv);
+            ptr_as_ptr::check(cx, expr, self.msrv);
         }
 
         if expr.span.from_expansion() {
@@ -562,18 +562,18 @@ impl<'tcx> LateLintPass<'tcx> for Casts {
                     cast_possible_wrap::check(cx, expr, cast_from, cast_to);
                     cast_precision_loss::check(cx, expr, cast_from, cast_to);
                     cast_sign_loss::check(cx, expr, cast_expr, cast_from, cast_to);
-                    cast_abs_to_unsigned::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv);
+                    cast_abs_to_unsigned::check(cx, expr, cast_expr, cast_from, cast_to, self.msrv);
                 }
-                cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv);
+                cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, self.msrv);
                 cast_enum_constructor::check(cx, expr, cast_expr, cast_from);
             }
         }
 
         cast_ref_to_mut::check(cx, expr);
         cast_ptr_alignment::check(cx, expr);
         char_lit_as_u8::check(cx, expr);
-        ptr_as_ptr::check(cx, expr, &self.msrv);
-        cast_slice_different_sizes::check(cx, expr, &self.msrv);
+        ptr_as_ptr::check(cx, expr, self.msrv);
+        cast_slice_different_sizes::check(cx, expr, self.msrv);
     }
 
     extract_msrv_attr!(LateContext);

clippy_lints/src/casts/ptr_as_ptr.rs

@@ -12,8 +12,8 @@ use rustc_semver::RustcVersion;
 
 use super::PTR_AS_PTR;
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: &Option<RustcVersion>) {
-    if !meets_msrv(msrv.as_ref(), &msrvs::POINTER_CAST) {
+pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Option<RustcVersion>) {
+    if !meets_msrv(msrv, msrvs::POINTER_CAST) {
         return;
     }
 

clippy_lints/src/checked_conversions.rs

@@ -57,7 +57,7 @@ impl_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
 
 impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
     fn check_expr(&mut self, cx: &LateContext<'_>, item: &Expr<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::TRY_FROM) {
+        if !meets_msrv(self.msrv, msrvs::TRY_FROM) {
             return;
         }
 

clippy_lints/src/from_over_into.rs

@@ -55,7 +55,7 @@ impl_lint_pass!(FromOverInto => [FROM_OVER_INTO]);
 
 impl<'tcx> LateLintPass<'tcx> for FromOverInto {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::RE_REBALANCING_COHERENCE) {
+        if !meets_msrv(self.msrv, msrvs::RE_REBALANCING_COHERENCE) {
             return;
         }
 

clippy_lints/src/if_then_some_else_none.rs

@@ -57,7 +57,7 @@ impl_lint_pass!(IfThenSomeElseNone => [IF_THEN_SOME_ELSE_NONE]);
 
 impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'tcx Expr<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::BOOL_THEN) {
+        if !meets_msrv(self.msrv, msrvs::BOOL_THEN) {
             return;
         }
 

clippy_lints/src/index_refutable_slice.rs

@@ -75,7 +75,7 @@ impl<'tcx> LateLintPass<'tcx> for IndexRefutableSlice {
             if !expr.span.from_expansion() || is_expn_of(expr.span, "if_chain").is_some();
             if let Some(IfLet {let_pat, if_then, ..}) = IfLet::hir(cx, expr);
             if !is_lint_allowed(cx, INDEX_REFUTABLE_SLICE, expr.hir_id);
-            if meets_msrv(self.msrv.as_ref(), &msrvs::SLICE_PATTERNS);
+            if meets_msrv(self.msrv, msrvs::SLICE_PATTERNS);
 
             let found_slices = find_slice_values(cx, let_pat);
             if !found_slices.is_empty();

clippy_lints/src/lib.rs

@@ -582,8 +582,17 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     });
 
     let avoid_breaking_exported_api = conf.avoid_breaking_exported_api;
+    let allow_expect_in_tests = conf.allow_expect_in_tests;
+    let allow_unwrap_in_tests = conf.allow_unwrap_in_tests;
     store.register_late_pass(move || Box::new(approx_const::ApproxConstant::new(msrv)));
-    store.register_late_pass(move || Box::new(methods::Methods::new(avoid_breaking_exported_api, msrv)));
+    store.register_late_pass(move || {
+        Box::new(methods::Methods::new(
+            avoid_breaking_exported_api,
+            msrv,
+            allow_expect_in_tests,
+            allow_unwrap_in_tests,
+        ))
+    });
     store.register_late_pass(move || Box::new(matches::Matches::new(msrv)));
     store.register_early_pass(move || Box::new(manual_non_exhaustive::ManualNonExhaustiveStruct::new(msrv)));
     store.register_late_pass(move || Box::new(manual_non_exhaustive::ManualNonExhaustiveEnum::new(msrv)));

clippy_lints/src/manual_bits.rs

@@ -48,7 +48,7 @@ impl_lint_pass!(ManualBits => [MANUAL_BITS]);
 
 impl<'tcx> LateLintPass<'tcx> for ManualBits {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::MANUAL_BITS) {
+        if !meets_msrv(self.msrv, msrvs::MANUAL_BITS) {
             return;
         }
 

clippy_lints/src/manual_non_exhaustive.rs

@@ -98,7 +98,7 @@ impl_lint_pass!(ManualNonExhaustiveEnum => [MANUAL_NON_EXHAUSTIVE]);
 
 impl EarlyLintPass for ManualNonExhaustiveStruct {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::NON_EXHAUSTIVE) {
+        if !meets_msrv(self.msrv, msrvs::NON_EXHAUSTIVE) {
             return;
         }
 
@@ -150,7 +150,7 @@ impl EarlyLintPass for ManualNonExhaustiveStruct {
 
 impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::NON_EXHAUSTIVE) {
+        if !meets_msrv(self.msrv, msrvs::NON_EXHAUSTIVE) {
             return;
         }
 

clippy_lints/src/manual_strip.rs

@@ -68,7 +68,7 @@ enum StripKind {
 
 impl<'tcx> LateLintPass<'tcx> for ManualStrip {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if !meets_msrv(self.msrv.as_ref(), &msrvs::STR_STRIP_PREFIX) {
+        if !meets_msrv(self.msrv, msrvs::STR_STRIP_PREFIX) {
             return;
         }
 

clippy_lints/src/map_clone.rs

@@ -144,7 +144,7 @@ impl MapClone {
     fn lint_explicit_closure(&self, cx: &LateContext<'_>, replace: Span, root: Span, is_copy: bool) {
         let mut applicability = Applicability::MachineApplicable;
 
-        let (message, sugg_method) = if is_copy && meets_msrv(self.msrv.as_ref(), &msrvs::ITERATOR_COPIED) {
+        let (message, sugg_method) = if is_copy && meets_msrv(self.msrv, msrvs::ITERATOR_COPIED) {
             ("you are using an explicit closure for copying elements", "copied")
         } else {
             ("you are using an explicit closure for cloning elements", "cloned")

clippy_lints/src/matches/mod.rs

@@ -658,7 +658,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches {
             }
             if !contains_cfg_arm(cx, expr, ex, arms) {
                 if source == MatchSource::Normal {
-                    if !(meets_msrv(self.msrv.as_ref(), &msrvs::MATCHES_MACRO)
+                    if !(meets_msrv(self.msrv, msrvs::MATCHES_MACRO)
                         && match_like_matches::check_match(cx, expr, ex, arms))
                     {
                         match_same_arms::check(cx, arms);
@@ -685,7 +685,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches {
             match_wild_err_arm::check(cx, ex, arms);
             wild_in_or_pats::check(cx, arms);
         } else {
-            if meets_msrv(self.msrv.as_ref(), &msrvs::MATCHES_MACRO) {
+            if meets_msrv(self.msrv, msrvs::MATCHES_MACRO) {
                 match_like_matches::check(cx, expr);
             }
             redundant_pattern_match::check(cx, expr);

clippy_lints/src/mem_replace.rs

@@ -254,7 +254,7 @@ impl<'tcx> LateLintPass<'tcx> for MemReplace {
             then {
                 check_replace_option_with_none(cx, src, dest, expr.span);
                 check_replace_with_uninit(cx, src, dest, expr.span);
-                if meets_msrv(self.msrv.as_ref(), &msrvs::MEM_TAKE) {
+                if meets_msrv(self.msrv, msrvs::MEM_TAKE) {
                     check_replace_with_default(cx, src, dest, expr.span);
                 }
             }

clippy_lints/src/methods/cloned_instead_of_copied.rs

@@ -10,16 +10,16 @@ use rustc_span::{sym, Span};
 
 use super::CLONED_INSTEAD_OF_COPIED;
 
-pub fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, span: Span, msrv: Option<&RustcVersion>) {
+pub fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, span: Span, msrv: Option<RustcVersion>) {
     let recv_ty = cx.typeck_results().expr_ty_adjusted(recv);
     let inner_ty = match recv_ty.kind() {
         // `Option<T>` -> `T`
         ty::Adt(adt, subst)
-            if cx.tcx.is_diagnostic_item(sym::Option, adt.did()) && meets_msrv(msrv, &msrvs::OPTION_COPIED) =>
+            if cx.tcx.is_diagnostic_item(sym::Option, adt.did()) && meets_msrv(msrv, msrvs::OPTION_COPIED) =>
         {
             subst.type_at(0)
         },
-        _ if is_trait_method(cx, expr, sym::Iterator) && meets_msrv(msrv, &msrvs::ITERATOR_COPIED) => {
+        _ if is_trait_method(cx, expr, sym::Iterator) && meets_msrv(msrv, msrvs::ITERATOR_COPIED) => {
             match get_iterator_item_ty(cx, recv_ty) {
                 // <T as Iterator>::Item
                 Some(ty) => ty,

clippy_lints/src/methods/err_expect.rs

@@ -13,15 +13,15 @@ pub(super) fn check(
     cx: &LateContext<'_>,
     _expr: &rustc_hir::Expr<'_>,
     recv: &rustc_hir::Expr<'_>,
-    msrv: Option<&RustcVersion>,
+    msrv: Option<RustcVersion>,
     expect_span: Span,
     err_span: Span,
 ) {
     if_chain! {
         if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result);
         // Test the version to make sure the lint can be showed (expect_err has been
         // introduced in rust 1.17.0 : https://github.com/rust-lang/rust/pull/38982)
-        if meets_msrv(msrv, &msrvs::EXPECT_ERR);
+        if meets_msrv(msrv, msrvs::EXPECT_ERR);
 
         // Grabs the `Result<T, E>` type
         let result_type = cx.typeck_results().expr_ty(recv);

clippy_lints/src/methods/expect_used.rs

@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::is_in_test_function;
 use clippy_utils::ty::is_type_diagnostic_item;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
@@ -7,7 +8,7 @@ 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<'_>, recv: &hir::Expr<'_>) {
+pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, allow_expect_in_tests: bool) {
     let obj_ty = cx.typeck_results().expr_ty(recv).peel_refs();
 
     let mess = if is_type_diagnostic_item(cx, obj_ty, sym::Option) {
@@ -18,6 +19,10 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr
         None
     };
 
+    if allow_expect_in_tests && is_in_test_function(cx.tcx, expr.hir_id) {
+        return;
+    }
+
     if let Some((lint, kind, none_value)) = mess {
         span_lint_and_help(
             cx,

clippy_lints/src/methods/filter_map_next.rs

@@ -14,10 +14,10 @@ pub(super) fn check<'tcx>(
     expr: &'tcx hir::Expr<'_>,
     recv: &'tcx hir::Expr<'_>,
     arg: &'tcx hir::Expr<'_>,
-    msrv: Option<&RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) {
     if is_trait_method(cx, expr, sym::Iterator) {
-        if !meets_msrv(msrv, &msrvs::ITERATOR_FIND_MAP) {
+        if !meets_msrv(msrv, msrvs::ITERATOR_FIND_MAP) {
             return;
         }
 

clippy_lints/src/methods/is_digit_ascii_radix.rs

@@ -15,9 +15,9 @@ pub(super) fn check<'tcx>(
     expr: &'tcx Expr<'_>,
     self_arg: &'tcx Expr<'_>,
     radix: &'tcx Expr<'_>,
-    msrv: Option<&RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) {
-    if !meets_msrv(msrv, &msrvs::IS_ASCII_DIGIT) {
+    if !meets_msrv(msrv, msrvs::IS_ASCII_DIGIT) {
         return;
     }
 

clippy_lints/src/methods/map_unwrap_or.rs

@@ -19,13 +19,13 @@ pub(super) fn check<'tcx>(
     recv: &'tcx hir::Expr<'_>,
     map_arg: &'tcx hir::Expr<'_>,
     unwrap_arg: &'tcx hir::Expr<'_>,
-    msrv: Option<&RustcVersion>,
+    msrv: Option<RustcVersion>,
 ) -> bool {
     // lint if the caller of `map()` is an `Option`
     let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Option);
     let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result);
 
-    if is_result && !meets_msrv(msrv, &msrvs::RESULT_MAP_OR_ELSE) {
+    if is_result && !meets_msrv(msrv, msrvs::RESULT_MAP_OR_ELSE) {
         return false;
     }