From 4768e5fb23c058eba90f0a1dcd6e9d5c0ecdee1b Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Mon, 14 Jun 2021 19:32:39 +0300 Subject: internal: document diagnostics crate --- .../src/handlers/missing_match_arms.rs | 929 +++++++++++++++++++++ 1 file changed, 929 insertions(+) create mode 100644 crates/ide_diagnostics/src/handlers/missing_match_arms.rs (limited to 'crates/ide_diagnostics/src/handlers/missing_match_arms.rs') diff --git a/crates/ide_diagnostics/src/handlers/missing_match_arms.rs b/crates/ide_diagnostics/src/handlers/missing_match_arms.rs new file mode 100644 index 000000000..9ea533d74 --- /dev/null +++ b/crates/ide_diagnostics/src/handlers/missing_match_arms.rs @@ -0,0 +1,929 @@ +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(crate) 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)] +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,) => {} + } +} + "#, + ); + } + } +} -- cgit v1.2.3