diff --git a/crates/ide-assists/src/handlers/replace_derive_with_manual_impl.rs b/crates/ide-assists/src/handlers/replace_derive_with_manual_impl.rs index 6fa15b28e4efc..2854701c088e5 100644 --- a/crates/ide-assists/src/handlers/replace_derive_with_manual_impl.rs +++ b/crates/ide-assists/src/handlers/replace_derive_with_manual_impl.rs @@ -907,7 +907,34 @@ impl PartialEq for Foo { } #[test] - fn add_custom_impl_partial_eq_tuple_enum() { + fn add_custom_impl_partial_eq_single_variant_tuple_enum() { + check_assist( + replace_derive_with_manual_impl, + r#" +//- minicore: eq, derive +#[derive(Partial$0Eq)] +enum Foo { + Bar(String), +} +"#, + r#" +enum Foo { + Bar(String), +} + +impl PartialEq for Foo { + $0fn eq(&self, other: &Self) -> bool { + match (self, other) { + (Self::Bar(l0), Self::Bar(r0)) => l0 == r0, + } + } +} +"#, + ) + } + + #[test] + fn add_custom_impl_partial_eq_partial_tuple_enum() { check_assist( replace_derive_with_manual_impl, r#" @@ -936,6 +963,37 @@ impl PartialEq for Foo { ) } + #[test] + fn add_custom_impl_partial_eq_tuple_enum() { + check_assist( + replace_derive_with_manual_impl, + r#" +//- minicore: eq, derive +#[derive(Partial$0Eq)] +enum Foo { + Bar(String), + Baz(i32), +} +"#, + r#" +enum Foo { + Bar(String), + Baz(i32), +} + +impl PartialEq for Foo { + $0fn eq(&self, other: &Self) -> bool { + match (self, other) { + (Self::Bar(l0), Self::Bar(r0)) => l0 == r0, + (Self::Baz(l0), Self::Baz(r0)) => l0 == r0, + _ => false, + } + } +} +"#, + ) + } + #[test] fn add_custom_impl_partial_eq_record_enum() { check_assist( diff --git a/crates/ide-assists/src/utils/gen_trait_fn_body.rs b/crates/ide-assists/src/utils/gen_trait_fn_body.rs index 6c87e66c134d7..f32e5ce97d2a0 100644 --- a/crates/ide-assists/src/utils/gen_trait_fn_body.rs +++ b/crates/ide-assists/src/utils/gen_trait_fn_body.rs @@ -516,10 +516,18 @@ fn gen_partial_eq(adt: &ast::Adt, func: &ast::Fn) -> Option<()> { let expr = match arms.len() { 0 => eq_check, - _ => { - if n_cases > arms.len() { + arms_len => { + // Generate the fallback arm when this enum has >1 variants. + // The fallback arm will be `_ => false,` if we've already gone through every case where the variants of self and other match, + // and `_ => std::mem::discriminant(self) == std::mem::discriminant(other),` otherwise. + if n_cases > 1 { let lhs = make::wildcard_pat().into(); - arms.push(make::match_arm(Some(lhs), None, eq_check)); + let rhs = if arms_len == n_cases { + make::expr_literal("false").into() + } else { + eq_check + }; + arms.push(make::match_arm(Some(lhs), None, rhs)); } let match_target = make::expr_tuple(vec![lhs_name, rhs_name]);