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ide-diagnostics: emit error for duplicate field in record pattern
Resolves a FIXME at hir-ty/src/infer/pat.rs that allowed
record patterns like `let S { foo, foo } = ...;` to type-check
with no error. Pushes the InferenceDiagnostic::DuplicateField
variant (added in rust-lang/rust-analyzer#22235) at the pattern
site; the cooked diagnostic already supports ExprOrPatId, so no
plumbing changes are needed.
Tests: struct pattern positive, enum variant pattern positive.
Part of rust-lang/rust-analyzer#22140.
Signed-off-by: Onyeka Obi <[email protected]>
| -rw-r--r-- | crates/hir-ty/src/infer/pat.rs | 5 | ||||
| -rw-r--r-- | crates/ide-diagnostics/src/handlers/duplicate_field.rs | 39 |
2 files changed, 43 insertions, 1 deletions
diff --git a/crates/hir-ty/src/infer/pat.rs b/crates/hir-ty/src/infer/pat.rs index 5d8b1196c0..ca2a0d87f7 100644 --- a/crates/hir-ty/src/infer/pat.rs +++ b/crates/hir-ty/src/infer/pat.rs @@ -1185,7 +1185,10 @@ https://doc.rust-lang.org/reference/types.html#trait-objects"; for (field_idx, field) in fields.iter().enumerate() { match used_fields.entry(field.name.clone()) { Occupied(_occupied) => { - // FIXME: Emit an error, field specified twice. + self.push_diagnostic(InferenceDiagnostic::DuplicateField { + field: field.pat.into(), + variant, + }); } Vacant(vacant) => { vacant.insert(field_idx); diff --git a/crates/ide-diagnostics/src/handlers/duplicate_field.rs b/crates/ide-diagnostics/src/handlers/duplicate_field.rs index 13d594066d..08748bf8af 100644 --- a/crates/ide-diagnostics/src/handlers/duplicate_field.rs +++ b/crates/ide-diagnostics/src/handlers/duplicate_field.rs @@ -81,4 +81,43 @@ fn main() { "#, ); } + + #[test] + fn duplicate_field_in_struct_pattern() { + check_diagnostics( + r#" +struct S { foo: i32, bar: i32 } +fn f(s: S) { + let S { + foo, + bar, + foo, + //^^^ error: field specified more than once + .. + } = s; + let _ = (foo, bar); +} +"#, + ); + } + + #[test] + fn duplicate_field_in_enum_variant_pattern() { + check_diagnostics( + r#" +enum E { V { foo: i32, bar: i32 } } +fn f(e: E) { + match e { + E::V { + foo, + bar, + foo, + //^^^ error: field specified more than once + .. + } => { let _ = (foo, bar); } + } +} +"#, + ); + } } |