use hir::InFile; use crate::{Diagnostic, DiagnosticsContext}; // Diagnostic: missing-match-arm // // This diagnostic is triggered if `match` block is missing one or more match arms. pub(super) fn missing_match_arms( ctx: &DiagnosticsContext<'_>, d: &hir::MissingMatchArms, ) -> Diagnostic { Diagnostic::new( "missing-match-arm", "missing match arm", ctx.sema.diagnostics_display_range(InFile::new(d.file, d.match_expr.clone().into())).range, ) } #[cfg(test)] pub(super) mod tests { use crate::tests::check_diagnostics; fn check_diagnostics_no_bails(ra_fixture: &str) { cov_mark::check_count!(validate_match_bailed_out, 0); crate::tests::check_diagnostics(ra_fixture) } #[test] fn empty_tuple() { check_diagnostics_no_bails( r#" fn main() { match () { } //^^ missing match arm match (()) { } //^^^^ missing match arm match () { _ => (), } match () { () => (), } match (()) { (()) => (), } } "#, ); } #[test] fn tuple_of_two_empty_tuple() { check_diagnostics_no_bails( r#" fn main() { match ((), ()) { } //^^^^^^^^ missing match arm match ((), ()) { ((), ()) => (), } } "#, ); } #[test] fn boolean() { check_diagnostics_no_bails( r#" fn test_main() { match false { } //^^^^^ missing match arm match false { true => (), } //^^^^^ missing match arm match (false, true) {} //^^^^^^^^^^^^^ missing match arm match (false, true) { (true, true) => (), } //^^^^^^^^^^^^^ missing match arm match (false, true) { //^^^^^^^^^^^^^ missing match arm (false, true) => (), (false, false) => (), (true, false) => (), } match (false, true) { (true, _x) => (), } //^^^^^^^^^^^^^ missing match arm match false { true => (), false => (), } match (false, true) { (false, _) => (), (true, false) => (), (_, true) => (), } match (false, true) { (true, true) => (), (true, false) => (), (false, true) => (), (false, false) => (), } match (false, true) { (true, _x) => (), (false, true) => (), (false, false) => (), } match (false, true, false) { (false, ..) => (), (true, ..) => (), } match (false, true, false) { (.., false) => (), (.., true) => (), } match (false, true, false) { (..) => (), } } "#, ); } #[test] fn tuple_of_tuple_and_bools() { check_diagnostics_no_bails( r#" fn main() { match (false, ((), false)) {} //^^^^^^^^^^^^^^^^^^^^ missing match arm match (false, ((), false)) { (true, ((), true)) => (), } //^^^^^^^^^^^^^^^^^^^^ missing match arm match (false, ((), false)) { (true, _) => (), } //^^^^^^^^^^^^^^^^^^^^ missing match arm match (false, ((), false)) { (true, ((), true)) => (), (true, ((), false)) => (), (false, ((), true)) => (), (false, ((), false)) => (), } match (false, ((), false)) { (true, ((), true)) => (), (true, ((), false)) => (), (false, _) => (), } } "#, ); } #[test] fn enums() { check_diagnostics_no_bails( r#" enum Either { A, B, } fn main() { match Either::A { } //^^^^^^^^^ missing match arm match Either::B { Either::A => (), } //^^^^^^^^^ missing match arm match &Either::B { //^^^^^^^^^^ missing match arm Either::A => (), } match Either::B { Either::A => (), Either::B => (), } match &Either::B { Either::A => (), Either::B => (), } } "#, ); } #[test] fn enum_containing_bool() { check_diagnostics_no_bails( r#" enum Either { A(bool), B } fn main() { match Either::B { } //^^^^^^^^^ missing match arm match Either::B { //^^^^^^^^^ missing match arm Either::A(true) => (), Either::B => () } match Either::B { Either::A(true) => (), Either::A(false) => (), Either::B => (), } match Either::B { Either::B => (), _ => (), } match Either::B { Either::A(_) => (), Either::B => (), } } "#, ); } #[test] fn enum_different_sizes() { check_diagnostics_no_bails( r#" enum Either { A(bool), B(bool, bool) } fn main() { match Either::A(false) { //^^^^^^^^^^^^^^^^ missing match arm Either::A(_) => (), Either::B(false, _) => (), } match Either::A(false) { Either::A(_) => (), Either::B(true, _) => (), Either::B(false, _) => (), } match Either::A(false) { Either::A(true) | Either::A(false) => (), Either::B(true, _) => (), Either::B(false, _) => (), } } "#, ); } #[test] fn tuple_of_enum_no_diagnostic() { check_diagnostics_no_bails( r#" enum Either { A(bool), B(bool, bool) } enum Either2 { C, D } fn main() { match (Either::A(false), Either2::C) { (Either::A(true), _) | (Either::A(false), _) => (), (Either::B(true, _), Either2::C) => (), (Either::B(false, _), Either2::C) => (), (Either::B(_, _), Either2::D) => (), } } "#, ); } #[test] fn or_pattern_no_diagnostic() { check_diagnostics_no_bails( r#" enum Either {A, B} fn main() { match (Either::A, Either::B) { (Either::A | Either::B, _) => (), } }"#, ) } #[test] fn mismatched_types() { cov_mark::check_count!(validate_match_bailed_out, 4); // Match statements with arms that don't match the // expression pattern do not fire this diagnostic. check_diagnostics( r#" enum Either { A, B } enum Either2 { C, D } fn main() { match Either::A { Either2::C => (), Either2::D => (), } match (true, false) { (true, false, true) => (), (true) => (), } match (true, false) { (true,) => {} } match (0) { () => () } match Unresolved::Bar { Unresolved::Baz => () } } "#, ); } #[test] fn mismatched_types_in_or_patterns() { cov_mark::check_count!(validate_match_bailed_out, 2); check_diagnostics( r#" fn main() { match false { true | () => {} } match (false,) { (true | (),) => {} } } "#, ); } #[test] fn malformed_match_arm_tuple_enum_missing_pattern() { // We are testing to be sure we don't panic here when the match // arm `Either::B` is missing its pattern. check_diagnostics_no_bails( r#" enum Either { A, B(u32) } fn main() { match Either::A { Either::A => (), Either::B() => (), } } "#, ); } #[test] fn malformed_match_arm_extra_fields() { cov_mark::check_count!(validate_match_bailed_out, 2); check_diagnostics( r#" enum A { B(isize, isize), C } fn main() { match A::B(1, 2) { A::B(_, _, _) => (), } match A::B(1, 2) { A::C(_) => (), } } "#, ); } #[test] fn expr_diverges() { cov_mark::check_count!(validate_match_bailed_out, 2); check_diagnostics( r#" enum Either { A, B } fn main() { match loop {} { Either::A => (), Either::B => (), } match loop {} { Either::A => (), } match loop { break Foo::A } { //^^^^^^^^^^^^^^^^^^^^^ missing match arm Either::A => (), } match loop { break Foo::A } { Either::A => (), Either::B => (), } } "#, ); } #[test] fn expr_partially_diverges() { check_diagnostics_no_bails( r#" enum Either { A(T), B } fn foo() -> Either { Either::B } fn main() -> u32 { match foo() { Either::A(val) => val, Either::B => 0, } } "#, ); } #[test] fn enum_record() { check_diagnostics_no_bails( r#" enum Either { A { foo: bool }, B } fn main() { let a = Either::A { foo: true }; match a { } //^ missing match arm match a { Either::A { foo: true } => () } //^ missing match arm match a { Either::A { } => (), //^^^^^^^^^ Missing structure fields: // | - foo Either::B => (), } match a { //^ missing match arm Either::A { } => (), } //^^^^^^^^^ Missing structure fields: // | - foo match a { Either::A { foo: true } => (), Either::A { foo: false } => (), Either::B => (), } match a { Either::A { foo: _ } => (), Either::B => (), } } "#, ); } #[test] fn enum_record_fields_out_of_order() { check_diagnostics_no_bails( r#" enum Either { A { foo: bool, bar: () }, B, } fn main() { let a = Either::A { foo: true, bar: () }; match a { //^ missing match arm Either::A { bar: (), foo: false } => (), Either::A { foo: true, bar: () } => (), } match a { Either::A { bar: (), foo: false } => (), Either::A { foo: true, bar: () } => (), Either::B => (), } } "#, ); } #[test] fn enum_record_ellipsis() { check_diagnostics_no_bails( r#" enum Either { A { foo: bool, bar: bool }, B, } fn main() { let a = Either::B; match a { //^ missing match arm Either::A { foo: true, .. } => (), Either::B => (), } match a { //^ missing match arm Either::A { .. } => (), } match a { Either::A { foo: true, .. } => (), Either::A { foo: false, .. } => (), Either::B => (), } match a { Either::A { .. } => (), Either::B => (), } } "#, ); } #[test] fn enum_tuple_partial_ellipsis() { check_diagnostics_no_bails( r#" enum Either { A(bool, bool, bool, bool), B, } fn main() { match Either::B { //^^^^^^^^^ missing match arm Either::A(true, .., true) => (), Either::A(true, .., false) => (), Either::A(false, .., false) => (), Either::B => (), } match Either::B { //^^^^^^^^^ missing match arm Either::A(true, .., true) => (), Either::A(true, .., false) => (), Either::A(.., true) => (), Either::B => (), } match Either::B { Either::A(true, .., true) => (), Either::A(true, .., false) => (), Either::A(false, .., true) => (), Either::A(false, .., false) => (), Either::B => (), } match Either::B { Either::A(true, .., true) => (), Either::A(true, .., false) => (), Either::A(.., true) => (), Either::A(.., false) => (), Either::B => (), } } "#, ); } #[test] fn never() { check_diagnostics_no_bails( r#" enum Never {} fn enum_(never: Never) { match never {} } fn enum_ref(never: &Never) { match never {} //^^^^^ missing match arm } fn bang(never: !) { match never {} } "#, ); } #[test] fn unknown_type() { cov_mark::check_count!(validate_match_bailed_out, 1); check_diagnostics( r#" enum Option { Some(T), None } fn main() { // `Never` is deliberately not defined so that it's an uninferred type. match Option::::None { None => (), Some(never) => match never {}, } match Option::::None { //^^^^^^^^^^^^^^^^^^^^^ missing match arm Option::Some(_never) => {}, } } "#, ); } #[test] fn tuple_of_bools_with_ellipsis_at_end_missing_arm() { check_diagnostics_no_bails( r#" fn main() { match (false, true, false) { //^^^^^^^^^^^^^^^^^^^^ missing match arm (false, ..) => (), } }"#, ); } #[test] fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() { check_diagnostics_no_bails( r#" fn main() { match (false, true, false) { //^^^^^^^^^^^^^^^^^^^^ missing match arm (.., false) => (), } }"#, ); } #[test] fn tuple_of_bools_with_ellipsis_in_middle_missing_arm() { check_diagnostics_no_bails( r#" fn main() { match (false, true, false) { //^^^^^^^^^^^^^^^^^^^^ missing match arm (true, .., false) => (), } }"#, ); } #[test] fn record_struct() { check_diagnostics_no_bails( r#"struct Foo { a: bool } fn main(f: Foo) { match f {} //^ missing match arm match f { Foo { a: true } => () } //^ missing match arm match &f { Foo { a: true } => () } //^^ missing match arm match f { Foo { a: _ } => () } match f { Foo { a: true } => (), Foo { a: false } => (), } match &f { Foo { a: true } => (), Foo { a: false } => (), } } "#, ); } #[test] fn tuple_struct() { check_diagnostics_no_bails( r#"struct Foo(bool); fn main(f: Foo) { match f {} //^ missing match arm match f { Foo(true) => () } //^ missing match arm match f { Foo(true) => (), Foo(false) => (), } } "#, ); } #[test] fn unit_struct() { check_diagnostics_no_bails( r#"struct Foo; fn main(f: Foo) { match f {} //^ missing match arm match f { Foo => () } } "#, ); } #[test] fn record_struct_ellipsis() { check_diagnostics_no_bails( r#"struct Foo { foo: bool, bar: bool } fn main(f: Foo) { match f { Foo { foo: true, .. } => () } //^ missing match arm match f { //^ missing match arm Foo { foo: true, .. } => (), Foo { bar: false, .. } => () } match f { Foo { .. } => () } match f { Foo { foo: true, .. } => (), Foo { foo: false, .. } => () } } "#, ); } #[test] fn internal_or() { check_diagnostics_no_bails( r#" fn main() { enum Either { A(bool), B } match Either::B { //^^^^^^^^^ missing match arm Either::A(true | false) => (), } } "#, ); } #[test] fn no_panic_at_unimplemented_subpattern_type() { cov_mark::check_count!(validate_match_bailed_out, 1); check_diagnostics( r#" struct S { a: char} fn main(v: S) { match v { S{ a } => {} } match v { S{ a: _x } => {} } match v { S{ a: 'a' } => {} } match v { S{..} => {} } match v { _ => {} } match v { } //^ missing match arm } "#, ); } #[test] fn binding() { check_diagnostics_no_bails( r#" fn main() { match true { _x @ true => {} false => {} } match true { _x @ true => {} } //^^^^ missing match arm } "#, ); } #[test] fn binding_ref_has_correct_type() { cov_mark::check_count!(validate_match_bailed_out, 1); // Asserts `PatKind::Binding(ref _x): bool`, not &bool. // If that's not true match checking will panic with "incompatible constructors" // FIXME: make facilities to test this directly like `tests::check_infer(..)` check_diagnostics( r#" enum Foo { A } fn main() { // FIXME: this should not bail out but current behavior is such as the old algorithm. // ExprValidator::validate_match(..) checks types of top level patterns incorrecly. match Foo::A { ref _x => {} Foo::A => {} } match (true,) { (ref _x,) => {} (true,) => {} } } "#, ); } #[test] fn enum_non_exhaustive() { check_diagnostics_no_bails( r#" //- /lib.rs crate:lib #[non_exhaustive] pub enum E { A, B } fn _local() { match E::A { _ => {} } match E::A { E::A => {} E::B => {} } match E::A { E::A | E::B => {} } } //- /main.rs crate:main deps:lib use lib::E; fn main() { match E::A { _ => {} } match E::A { //^^^^ missing match arm E::A => {} E::B => {} } match E::A { //^^^^ missing match arm E::A | E::B => {} } } "#, ); } #[test] fn match_guard() { check_diagnostics_no_bails( r#" fn main() { match true { true if false => {} true => {} false => {} } match true { //^^^^ missing match arm true if false => {} false => {} } } "#, ); } #[test] fn pattern_type_is_of_substitution() { cov_mark::check!(match_check_wildcard_expanded_to_substitutions); check_diagnostics_no_bails( r#" struct Foo(T); struct Bar; fn main() { match Foo(Bar) { _ | Foo(Bar) => {} } } "#, ); } #[test] fn record_struct_no_such_field() { cov_mark::check_count!(validate_match_bailed_out, 1); check_diagnostics( r#" struct Foo { } fn main(f: Foo) { match f { Foo { bar } => () } } "#, ); } #[test] fn match_ergonomics_issue_9095() { check_diagnostics_no_bails( r#" enum Foo { A(T) } fn main() { match &Foo::A(true) { _ => {} Foo::A(_) => {} } } "#, ); } mod false_negatives { //! The implementation of match checking here is a work in progress. As we roll this out, we //! prefer false negatives to false positives (ideally there would be no false positives). This //! test module should document known false negatives. Eventually we will have a complete //! implementation of match checking and this module will be empty. //! //! The reasons for documenting known false negatives: //! //! 1. It acts as a backlog of work that can be done to improve the behavior of the system. //! 2. It ensures the code doesn't panic when handling these cases. use super::*; #[test] fn integers() { cov_mark::check_count!(validate_match_bailed_out, 1); // We don't currently check integer exhaustiveness. check_diagnostics( r#" fn main() { match 5 { 10 => (), 11..20 => (), } } "#, ); } #[test] fn reference_patterns_at_top_level() { cov_mark::check_count!(validate_match_bailed_out, 1); check_diagnostics( r#" fn main() { match &false { &true => {} } } "#, ); } #[test] fn reference_patterns_in_fields() { cov_mark::check_count!(validate_match_bailed_out, 2); check_diagnostics( r#" fn main() { match (&false,) { (true,) => {} } match (&false,) { (&true,) => {} } } "#, ); } } }