Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-diagnostics/src/handlers/mutability_errors.rs')
| -rw-r--r-- | crates/ide-diagnostics/src/handlers/mutability_errors.rs | 104 |
1 files changed, 95 insertions, 9 deletions
diff --git a/crates/ide-diagnostics/src/handlers/mutability_errors.rs b/crates/ide-diagnostics/src/handlers/mutability_errors.rs index 96470265d1..17a70f5701 100644 --- a/crates/ide-diagnostics/src/handlers/mutability_errors.rs +++ b/crates/ide-diagnostics/src/handlers/mutability_errors.rs @@ -565,8 +565,55 @@ fn f(x: [(i32, u8); 10]) { } #[test] + fn overloaded_index() { + check_diagnostics( + r#" +//- minicore: index +use core::ops::{Index, IndexMut}; + +struct Foo; +impl Index<usize> for Foo { + type Output = (i32, u8); + fn index(&self, index: usize) -> &(i32, u8) { + &(5, 2) + } +} +impl IndexMut<usize> for Foo { + fn index_mut(&mut self, index: usize) -> &mut (i32, u8) { + &mut (5, 2) + } +} +fn f() { + let mut x = Foo; + //^^^^^ 💡 weak: variable does not need to be mutable + let y = &x[2]; + let x = Foo; + let y = &mut x[2]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + let mut x = &mut Foo; + //^^^^^ 💡 weak: variable does not need to be mutable + let y: &mut (i32, u8) = &mut x[2]; + let x = Foo; + let ref mut y = x[7]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + let (ref mut y, _) = x[3]; + //^^^^ 💡 error: cannot mutate immutable variable `x` + match x[10] { + //^^^^^ 💡 error: cannot mutate immutable variable `x` + (ref y, _) => (), + (_, ref mut y) => (), + } + let mut x = Foo; + let mut i = 5; + //^^^^^ 💡 weak: variable does not need to be mutable + let y = &mut x[i]; +} +"#, + ); + } + + #[test] fn overloaded_deref() { - // FIXME: check for false negative check_diagnostics( r#" //- minicore: deref_mut @@ -574,22 +621,36 @@ use core::ops::{Deref, DerefMut}; struct Foo; impl Deref for Foo { - type Target = i32; - fn deref(&self) -> &i32 { - &5 + type Target = (i32, u8); + fn deref(&self) -> &(i32, u8) { + &(5, 2) } } impl DerefMut for Foo { - fn deref_mut(&mut self) -> &mut i32 { - &mut 5 + fn deref_mut(&mut self) -> &mut (i32, u8) { + &mut (5, 2) } } fn f() { - let x = Foo; + let mut x = Foo; + //^^^^^ 💡 weak: variable does not need to be mutable let y = &*x; let x = Foo; - let mut x = Foo; - let y: &mut i32 = &mut x; + let y = &mut *x; + //^^ 💡 error: cannot mutate immutable variable `x` + let x = Foo; + let x = Foo; + let y: &mut (i32, u8) = &mut x; + //^^^^^^ 💡 error: cannot mutate immutable variable `x` + let ref mut y = *x; + //^^ 💡 error: cannot mutate immutable variable `x` + let (ref mut y, _) = *x; + //^^ 💡 error: cannot mutate immutable variable `x` + match *x { + //^^ 💡 error: cannot mutate immutable variable `x` + (ref y, _) => (), + (_, ref mut y) => (), + } } "#, ); @@ -632,6 +693,31 @@ fn f(inp: (Foo, Foo, Foo, Foo)) { } #[test] + fn fn_traits() { + check_diagnostics( + r#" +//- minicore: fn +fn fn_ref(mut x: impl Fn(u8) -> u8) -> u8 { + //^^^^^ 💡 weak: variable does not need to be mutable + x(2) +} +fn fn_mut(x: impl FnMut(u8) -> u8) -> u8 { + x(2) + //^ 💡 error: cannot mutate immutable variable `x` +} +fn fn_borrow_mut(mut x: &mut impl FnMut(u8) -> u8) -> u8 { + //^^^^^ 💡 weak: variable does not need to be mutable + x(2) +} +fn fn_once(mut x: impl FnOnce(u8) -> u8) -> u8 { + //^^^^^ 💡 weak: variable does not need to be mutable + x(2) +} +"#, + ); + } + + #[test] fn respect_allow_unused_mut() { // FIXME: respect check_diagnostics( |