[`as_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#as_conversions
[`as_underscore`]: https://rust-lang.github.io/rust-clippy/master/index.html#as_underscore
[`assertions_on_constants`]: https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_constants
+[`assertions_on_result_states`]: https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_result_states
[`assign_op_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[`assign_ops`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_ops
[`async_yields_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#async_yields_async
--- /dev/null
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::macros::{find_assert_args, root_macro_call_first_node, PanicExpn};
+use clippy_utils::path_res;
+use clippy_utils::source::snippet_with_context;
+use clippy_utils::ty::{implements_trait, is_copy, is_type_diagnostic_item};
+use clippy_utils::usage::local_used_after_expr;
+use rustc_errors::Applicability;
+use rustc_hir::def::Res;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `assert!(r.is_ok())` or `assert!(r.is_err())` calls.
+ ///
+ /// ### Why is this bad?
+ /// An assertion failure cannot output an useful message of the error.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// # let r = Ok::<_, ()>(());
+ /// assert!(r.is_ok());
+ /// # let r = Err::<_, ()>(());
+ /// assert!(r.is_err());
+ /// ```
+ #[clippy::version = "1.64.0"]
+ pub ASSERTIONS_ON_RESULT_STATES,
+ style,
+ "`assert!(r.is_ok())`/`assert!(r.is_err())` gives worse error message than directly calling `r.unwrap()`/`r.unwrap_err()`"
+}
+
+declare_lint_pass!(AssertionsOnResultStates => [ASSERTIONS_ON_RESULT_STATES]);
+
+impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if let Some(macro_call) = root_macro_call_first_node(cx, e)
+ && matches!(cx.tcx.get_diagnostic_name(macro_call.def_id), Some(sym::assert_macro))
+ && let Some((condition, panic_expn)) = find_assert_args(cx, e, macro_call.expn)
+ && matches!(panic_expn, PanicExpn::Empty)
+ && let ExprKind::MethodCall(method_segment, [recv], _) = condition.kind
+ && let result_type_with_refs = cx.typeck_results().expr_ty(recv)
+ && let result_type = result_type_with_refs.peel_refs()
+ && is_type_diagnostic_item(cx, result_type, sym::Result)
+ && let ty::Adt(_, substs) = result_type.kind()
+ {
+ if !is_copy(cx, result_type) {
+ if result_type_with_refs != result_type {
+ return;
+ } else if let Res::Local(binding_id) = path_res(cx, recv)
+ && local_used_after_expr(cx, binding_id, recv) {
+ return;
+ }
+ }
+ let mut app = Applicability::MachineApplicable;
+ match method_segment.ident.as_str() {
+ "is_ok" if has_debug_impl(cx, substs.type_at(1)) => {
+ span_lint_and_sugg(
+ cx,
+ ASSERTIONS_ON_RESULT_STATES,
+ macro_call.span,
+ "called `assert!` with `Result::is_ok`",
+ "replace with",
+ format!(
+ "{}.unwrap()",
+ snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
+ ),
+ app,
+ );
+ }
+ "is_err" if has_debug_impl(cx, substs.type_at(0)) => {
+ span_lint_and_sugg(
+ cx,
+ ASSERTIONS_ON_RESULT_STATES,
+ macro_call.span,
+ "called `assert!` with `Result::is_err`",
+ "replace with",
+ format!(
+ "{}.unwrap_err()",
+ snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
+ ),
+ app,
+ );
+ }
+ _ => (),
+ };
+ }
+ }
+}
+
+/// This checks whether a given type is known to implement Debug.
+fn has_debug_impl<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ cx.tcx
+ .get_diagnostic_item(sym::Debug)
+ .map_or(false, |debug| implements_trait(cx, ty, debug, &[]))
+}
LintId::of(almost_complete_letter_range::ALMOST_COMPLETE_LETTER_RANGE),
LintId::of(approx_const::APPROX_CONSTANT),
LintId::of(assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(assertions_on_result_states::ASSERTIONS_ON_RESULT_STATES),
LintId::of(async_yields_async::ASYNC_YIELDS_ASYNC),
LintId::of(attrs::BLANKET_CLIPPY_RESTRICTION_LINTS),
LintId::of(attrs::DEPRECATED_CFG_ATTR),
asm_syntax::INLINE_ASM_X86_ATT_SYNTAX,
asm_syntax::INLINE_ASM_X86_INTEL_SYNTAX,
assertions_on_constants::ASSERTIONS_ON_CONSTANTS,
+ assertions_on_result_states::ASSERTIONS_ON_RESULT_STATES,
async_yields_async::ASYNC_YIELDS_ASYNC,
attrs::ALLOW_ATTRIBUTES_WITHOUT_REASON,
attrs::BLANKET_CLIPPY_RESTRICTION_LINTS,
store.register_group(true, "clippy::style", Some("clippy_style"), vec![
LintId::of(assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(assertions_on_result_states::ASSERTIONS_ON_RESULT_STATES),
LintId::of(blacklisted_name::BLACKLISTED_NAME),
LintId::of(blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS),
LintId::of(bool_assert_comparison::BOOL_ASSERT_COMPARISON),
mod as_underscore;
mod asm_syntax;
mod assertions_on_constants;
+mod assertions_on_result_states;
mod async_yields_async;
mod attrs;
mod await_holding_invalid;
store.register_late_pass(|| Box::new(unnecessary_sort_by::UnnecessarySortBy));
store.register_late_pass(move || Box::new(unnecessary_wraps::UnnecessaryWraps::new(avoid_breaking_exported_api)));
store.register_late_pass(|| Box::new(assertions_on_constants::AssertionsOnConstants));
+ store.register_late_pass(|| Box::new(assertions_on_result_states::AssertionsOnResultStates));
store.register_late_pass(|| Box::new(transmuting_null::TransmutingNull));
store.register_late_pass(|| Box::new(path_buf_push_overwrite::PathBufPushOverwrite));
store.register_late_pass(|| Box::new(inherent_to_string::InherentToString));
--- /dev/null
+// run-rustfix
+#![warn(clippy::assertions_on_result_states)]
+
+use std::result::Result;
+
+struct Foo;
+
+#[derive(Debug)]
+struct DebugFoo;
+
+#[derive(Copy, Clone, Debug)]
+struct CopyFoo;
+
+macro_rules! get_ok_macro {
+ () => {
+ Ok::<_, DebugFoo>(Foo)
+ };
+}
+
+fn main() {
+ // test ok
+ let r: Result<Foo, DebugFoo> = Ok(Foo);
+ debug_assert!(r.is_ok());
+ r.unwrap();
+
+ // test ok with non-debug error type
+ let r: Result<Foo, Foo> = Ok(Foo);
+ assert!(r.is_ok());
+
+ // test temporary ok
+ fn get_ok() -> Result<Foo, DebugFoo> {
+ Ok(Foo)
+ }
+ get_ok().unwrap();
+
+ // test macro ok
+ get_ok_macro!().unwrap();
+
+ // test ok that shouldn't be moved
+ let r: Result<CopyFoo, DebugFoo> = Ok(CopyFoo);
+ fn test_ref_unmoveable_ok(r: &Result<CopyFoo, DebugFoo>) {
+ assert!(r.is_ok());
+ }
+ test_ref_unmoveable_ok(&r);
+ assert!(r.is_ok());
+ r.unwrap();
+
+ // test ok that is copied
+ let r: Result<CopyFoo, CopyFoo> = Ok(CopyFoo);
+ r.unwrap();
+ r.unwrap();
+
+ // test reference to ok
+ let r: Result<CopyFoo, CopyFoo> = Ok(CopyFoo);
+ fn test_ref_copy_ok(r: &Result<CopyFoo, CopyFoo>) {
+ r.unwrap();
+ }
+ test_ref_copy_ok(&r);
+ r.unwrap();
+
+ // test err
+ let r: Result<DebugFoo, Foo> = Err(Foo);
+ debug_assert!(r.is_err());
+ r.unwrap_err();
+
+ // test err with non-debug value type
+ let r: Result<Foo, Foo> = Err(Foo);
+ assert!(r.is_err());
+}
--- /dev/null
+// run-rustfix
+#![warn(clippy::assertions_on_result_states)]
+
+use std::result::Result;
+
+struct Foo;
+
+#[derive(Debug)]
+struct DebugFoo;
+
+#[derive(Copy, Clone, Debug)]
+struct CopyFoo;
+
+macro_rules! get_ok_macro {
+ () => {
+ Ok::<_, DebugFoo>(Foo)
+ };
+}
+
+fn main() {
+ // test ok
+ let r: Result<Foo, DebugFoo> = Ok(Foo);
+ debug_assert!(r.is_ok());
+ assert!(r.is_ok());
+
+ // test ok with non-debug error type
+ let r: Result<Foo, Foo> = Ok(Foo);
+ assert!(r.is_ok());
+
+ // test temporary ok
+ fn get_ok() -> Result<Foo, DebugFoo> {
+ Ok(Foo)
+ }
+ assert!(get_ok().is_ok());
+
+ // test macro ok
+ assert!(get_ok_macro!().is_ok());
+
+ // test ok that shouldn't be moved
+ let r: Result<CopyFoo, DebugFoo> = Ok(CopyFoo);
+ fn test_ref_unmoveable_ok(r: &Result<CopyFoo, DebugFoo>) {
+ assert!(r.is_ok());
+ }
+ test_ref_unmoveable_ok(&r);
+ assert!(r.is_ok());
+ r.unwrap();
+
+ // test ok that is copied
+ let r: Result<CopyFoo, CopyFoo> = Ok(CopyFoo);
+ assert!(r.is_ok());
+ r.unwrap();
+
+ // test reference to ok
+ let r: Result<CopyFoo, CopyFoo> = Ok(CopyFoo);
+ fn test_ref_copy_ok(r: &Result<CopyFoo, CopyFoo>) {
+ assert!(r.is_ok());
+ }
+ test_ref_copy_ok(&r);
+ r.unwrap();
+
+ // test err
+ let r: Result<DebugFoo, Foo> = Err(Foo);
+ debug_assert!(r.is_err());
+ assert!(r.is_err());
+
+ // test err with non-debug value type
+ let r: Result<Foo, Foo> = Err(Foo);
+ assert!(r.is_err());
+}
--- /dev/null
+error: called `assert!` with `Result::is_ok`
+ --> $DIR/assertions_on_result_states.rs:24:5
+ |
+LL | assert!(r.is_ok());
+ | ^^^^^^^^^^^^^^^^^^ help: replace with: `r.unwrap()`
+ |
+ = note: `-D clippy::assertions-on-result-states` implied by `-D warnings`
+
+error: called `assert!` with `Result::is_ok`
+ --> $DIR/assertions_on_result_states.rs:34:5
+ |
+LL | assert!(get_ok().is_ok());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `get_ok().unwrap()`
+
+error: called `assert!` with `Result::is_ok`
+ --> $DIR/assertions_on_result_states.rs:37:5
+ |
+LL | assert!(get_ok_macro!().is_ok());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `get_ok_macro!().unwrap()`
+
+error: called `assert!` with `Result::is_ok`
+ --> $DIR/assertions_on_result_states.rs:50:5
+ |
+LL | assert!(r.is_ok());
+ | ^^^^^^^^^^^^^^^^^^ help: replace with: `r.unwrap()`
+
+error: called `assert!` with `Result::is_ok`
+ --> $DIR/assertions_on_result_states.rs:56:9
+ |
+LL | assert!(r.is_ok());
+ | ^^^^^^^^^^^^^^^^^^ help: replace with: `r.unwrap()`
+
+error: called `assert!` with `Result::is_err`
+ --> $DIR/assertions_on_result_states.rs:64:5
+ |
+LL | assert!(r.is_err());
+ | ^^^^^^^^^^^^^^^^^^^ help: replace with: `r.unwrap_err()`
+
+error: aborting due to 6 previous errors
+
projects / rust.git / commitdiff