internal: Make diagnostics experimental by default

crates/ide-diagnostics/src/handlers/await_outside_of_async.rs

@@ -14,6 +14,7 @@ pub(crate) fn await_outside_of_async(
         format!("`await` is used inside {}, which is not an `async` context", d.location),
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/bad_rtn.rs

@@ -12,6 +12,7 @@ pub(crate) fn bad_rtn(ctx: &DiagnosticsContext<'_>, d: &hir::BadRtn) -> Diagnost
         "return type notation not allowed in this position yet",
         d.rtn.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/break_outside_of_loop.rs

@@ -19,6 +19,7 @@ pub(crate) fn break_outside_of_loop(
         message,
         d.expr.map(|it| it.into()),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/elided_lifetimes_in_path.rs

@@ -15,15 +15,13 @@ pub(crate) fn elided_lifetimes_in_path(
             "implicit elided lifetime not allowed here",
             d.generics_or_segment.map(Into::into),
         )
-        .experimental()
     } else {
         Diagnostic::new_with_syntax_node_ptr(
             ctx,
             DiagnosticCode::RustcLint("elided_lifetimes_in_paths"),
             "hidden lifetime parameters in types are deprecated",
             d.generics_or_segment.map(Into::into),
         )
-        .experimental()
     }
 }
 

crates/ide-diagnostics/src/handlers/expected_function.rs

@@ -15,7 +15,6 @@ pub(crate) fn expected_function(
         format!("expected function, found {}", d.found.display(ctx.sema.db, ctx.display_target)),
         d.call.map(|it| it.into()),
     )
-    .experimental()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/generic_args_prohibited.rs

@@ -21,6 +21,7 @@ pub(crate) fn generic_args_prohibited(
         describe_reason(d.reason),
         d.args.map(Into::into),
     )
+    .stable()
     .with_fixes(fixes(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/inactive_code.rs

@@ -33,6 +33,7 @@ pub(crate) fn inactive_code(
         message,
         ctx.sema.diagnostics_display_range(d.node),
     )
+    .stable()
     .with_unused(true);
     Some(res)
 }

crates/ide-diagnostics/src/handlers/incoherent_impl.rs

@@ -19,6 +19,7 @@ pub(crate) fn incoherent_impl(ctx: &DiagnosticsContext<'_>, d: &hir::IncoherentI
         "cannot define inherent `impl` for foreign type".to_owned(),
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/incorrect_case.rs

@@ -29,6 +29,7 @@ pub(crate) fn incorrect_case(ctx: &DiagnosticsContext<'_>, d: &hir::IncorrectCas
         ),
         InFile::new(d.file, d.ident.into()),
     )
+    .stable()
     .with_fixes(fixes(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/incorrect_generics_len.rs

@@ -28,7 +28,6 @@ pub(crate) fn incorrect_generics_len(
         message,
         d.generics_or_segment.map(Into::into),
     )
-    .experimental()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/incorrect_generics_order.rs

@@ -28,6 +28,7 @@ pub(crate) fn incorrect_generics_order(
         message,
         d.provided_arg.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/invalid_cast.rs

@@ -100,7 +100,7 @@ pub(crate) fn invalid_cast(ctx: &DiagnosticsContext<'_>, d: &hir::InvalidCast) -
         //     "cannot cast to a pointer of an unknown kind".to_owned(),
         // ),
     };
-    Diagnostic::new(code, message, display_range)
+    Diagnostic::new(code, message, display_range).stable()
 }
 
 // Diagnostic: cast-to-unsized
@@ -113,6 +113,7 @@ pub(crate) fn cast_to_unsized(ctx: &DiagnosticsContext<'_>, d: &hir::CastToUnsiz
         format_ty!(ctx, "cast to unsized type: `{}`", d.cast_ty),
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/invalid_derive_target.rs

@@ -15,6 +15,7 @@ pub(crate) fn invalid_derive_target(
         "`derive` may only be applied to `struct`s, `enum`s and `union`s",
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/macro_error.rs

@@ -19,6 +19,7 @@ pub(crate) fn macro_error(ctx: &DiagnosticsContext<'_>, d: &hir::MacroError) ->
         d.message.clone(),
         display_range,
     )
+    .stable()
 }
 
 // Diagnostic: macro-def-error
@@ -33,6 +34,7 @@ pub(crate) fn macro_def_error(ctx: &DiagnosticsContext<'_>, d: &hir::MacroDefErr
         d.message.clone(),
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/malformed_derive.rs

@@ -14,6 +14,7 @@ pub(crate) fn malformed_derive(
         "malformed derive input, derive attributes are of the form `#[derive(Derive1, Derive2, ...)]`",
         display_range,
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/mismatched_arg_count.rs

@@ -26,6 +26,7 @@ pub(crate) fn mismatched_tuple_struct_pat_arg_count(
         message,
         invalid_args_range(ctx, d.expr_or_pat, d.expected, d.found),
     )
+    .stable()
 }
 
 // Diagnostic: mismatched-arg-count
@@ -42,6 +43,7 @@ pub(crate) fn mismatched_arg_count(
         message,
         invalid_args_range(ctx, d.call_expr, d.expected, d.found),
     )
+    .stable()
 }
 
 fn invalid_args_range(

crates/ide-diagnostics/src/handlers/missing_fields.rs

@@ -47,6 +47,7 @@ pub(crate) fn missing_fields(ctx: &DiagnosticsContext<'_>, d: &hir::MissingField
     );
 
     Diagnostic::new_with_syntax_node_ptr(ctx, DiagnosticCode::RustcHardError("E0063"), message, ptr)
+        .stable()
         .with_fixes(fixes(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/missing_lifetime.rs

@@ -13,7 +13,6 @@ pub(crate) fn missing_lifetime(
         "missing lifetime specifier",
         d.generics_or_segment.map(Into::into),
     )
-    .experimental()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/missing_match_arms.rs

@@ -13,6 +13,7 @@ pub(crate) fn missing_match_arms(
         format!("missing match arm: {}", d.uncovered_patterns),
         d.scrutinee_expr.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/missing_unsafe.rs

@@ -23,6 +23,7 @@ pub(crate) fn missing_unsafe(ctx: &DiagnosticsContext<'_>, d: &hir::MissingUnsaf
         format!("{operation} is unsafe and requires an unsafe function or block"),
         d.node.map(|it| it.into()),
     )
+    .stable()
     .with_fixes(fixes(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/moved_out_of_ref.rs

@@ -11,7 +11,7 @@ pub(crate) fn moved_out_of_ref(ctx: &DiagnosticsContext<'_>, d: &hir::MovedOutOf
         format!("cannot move `{}` out of reference", d.ty.display(ctx.sema.db, ctx.display_target)),
         d.span,
     )
-    .experimental() // spans are broken, and I'm not sure how precise we can detect copy types
+    // spans are broken, and I'm not sure how precise we can detect copy types
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/mutability_errors.rs

@@ -55,6 +55,7 @@ pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Option
             ),
             span,
         )
+        .stable()
         .with_fixes(fixes),
     )
 }
@@ -94,7 +95,7 @@ pub(crate) fn unused_mut(ctx: &DiagnosticsContext<'_>, d: &hir::UnusedMut) -> Op
             "variable does not need to be mutable",
             ast,
         )
-        .experimental() // Not supporting `#[allow(unused_mut)]` in proc macros leads to false positive.
+        // Not supporting `#[allow(unused_mut)]` in proc macros leads to false positive, hence not stable.
         .with_fixes(fixes),
     )
 }

crates/ide-diagnostics/src/handlers/no_such_field.rs

@@ -22,6 +22,7 @@ pub(crate) fn no_such_field(ctx: &DiagnosticsContext<'_>, d: &hir::NoSuchField)
             "field is private",
             node,
         )
+        .stable()
     } else {
         Diagnostic::new_with_syntax_node_ptr(
             ctx,
@@ -32,6 +33,7 @@ pub(crate) fn no_such_field(ctx: &DiagnosticsContext<'_>, d: &hir::NoSuchField)
             "no such field",
             node,
         )
+        .stable()
         .with_fixes(fixes(ctx, d))
     }
 }

crates/ide-diagnostics/src/handlers/non_exhaustive_let.rs

@@ -14,6 +14,7 @@ pub(crate) fn non_exhaustive_let(
         format!("non-exhaustive pattern: {}", d.uncovered_patterns),
         d.pat.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/parenthesized_generic_args_without_fn_trait.rs

@@ -14,6 +14,7 @@ pub(crate) fn parenthesized_generic_args_without_fn_trait(
         "parenthesized type parameters may only be used with a `Fn` trait",
         d.args.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/private_assoc_item.rs

@@ -28,6 +28,7 @@ pub(crate) fn private_assoc_item(
         ),
         d.expr_or_pat.map(Into::into),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/private_field.rs

@@ -15,6 +15,7 @@ pub(crate) fn private_field(ctx: &DiagnosticsContext<'_>, d: &hir::PrivateField)
         ),
         d.expr.map(|it| it.into()),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/remove_trailing_return.rs

@@ -31,6 +31,7 @@ pub(crate) fn remove_trailing_return(
             "replace return <expr>; with <expr>",
             display_range,
         )
+        .stable()
         .with_fixes(fixes(ctx, d)),
     )
 }

crates/ide-diagnostics/src/handlers/remove_unnecessary_else.rs

@@ -36,7 +36,6 @@ pub(crate) fn remove_unnecessary_else(
             "remove unnecessary else block",
             display_range,
         )
-        .experimental()
         .with_fixes(fixes(ctx, d)),
     )
 }

crates/ide-diagnostics/src/handlers/replace_filter_map_next_with_find_map.rs

@@ -21,6 +21,7 @@ pub(crate) fn replace_filter_map_next_with_find_map(
         "replace filter_map(..).next() with find_map(..)",
         InFile::new(d.file, d.next_expr.into()),
     )
+    .stable()
     .with_fixes(fixes(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/trait_impl_incorrect_safety.rs

@@ -33,6 +33,7 @@ pub(crate) fn trait_impl_incorrect_safety(
             },
         ),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/trait_impl_missing_assoc_item.rs

@@ -29,6 +29,7 @@ pub(crate) fn trait_impl_missing_assoc_item(
             &|impl_| impl_.trait_().map(|t| t.syntax().text_range()),
         ),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/trait_impl_orphan.rs

@@ -16,8 +16,6 @@ pub(crate) fn trait_impl_orphan(
             .to_owned(),
         InFile::new(d.file_id, d.impl_.into()),
     )
-    // Not yet checked for false positives
-    .experimental()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/trait_impl_redundant_assoc_item.rs

@@ -61,6 +61,7 @@ pub(crate) fn trait_impl_redundant_assoc_item(
         format!("{redundant_item_name} is not a member of trait `{trait_name}`"),
         ide_db::FileRange { file_id: file_id.file_id(ctx.sema.db), range },
     )
+    .stable()
     .with_fixes(quickfix_for_redundant_assoc_item(
         ctx,
         d,

crates/ide-diagnostics/src/handlers/type_mismatch.rs

@@ -53,8 +53,8 @@ pub(crate) fn type_mismatch(ctx: &DiagnosticsContext<'_>, d: &hir::TypeMismatch)
         display_range,
     )
     .with_fixes(fixes(ctx, d));
-    if diag.fixes.is_none() {
-        diag.experimental = true;
+    if diag.fixes.is_some() {
+        diag.experimental = false;
     }
     diag
 }

crates/ide-diagnostics/src/handlers/typed_hole.rs

@@ -37,6 +37,7 @@ pub(crate) fn typed_hole(ctx: &DiagnosticsContext<'_>, d: &hir::TypedHole) -> Di
     };
 
     Diagnostic::new(DiagnosticCode::RustcHardError("typed-hole"), message, display_range)
+        .stable()
         .with_fixes(fixes)
 }
 

crates/ide-diagnostics/src/handlers/undeclared_label.rs

@@ -12,6 +12,7 @@ pub(crate) fn undeclared_label(
         format!("use of undeclared label `{}`", name.display(ctx.sema.db, ctx.edition)),
         d.node.map(|it| it.into()),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/unimplemented_builtin_macro.rs

@@ -13,4 +13,5 @@ pub(crate) fn unimplemented_builtin_macro(
         "unimplemented built-in macro".to_owned(),
         d.node,
     )
+    .stable()
 }

crates/ide-diagnostics/src/handlers/unreachable_label.rs

@@ -12,6 +12,7 @@ pub(crate) fn unreachable_label(
         format!("use of unreachable label `{}`", name.display(ctx.sema.db, ctx.edition)),
         d.node.map(|it| it.into()),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/unresolved_assoc_item.rs

@@ -13,7 +13,6 @@ pub(crate) fn unresolved_assoc_item(
         "no such associated item",
         d.expr_or_pat.map(Into::into),
     )
-    .experimental()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/unresolved_extern_crate.rs

@@ -13,6 +13,7 @@ pub(crate) fn unresolved_extern_crate(
         "unresolved extern crate",
         d.decl.map(|it| it.into()),
     )
+    .stable()
 }
 
 #[cfg(test)]

crates/ide-diagnostics/src/handlers/unresolved_field.rs

@@ -52,7 +52,6 @@ pub(crate) fn unresolved_field(
         }),
     )
     .with_fixes(fixes(ctx, d))
-    .experimental()
 }
 
 fn fixes(ctx: &DiagnosticsContext<'_>, d: &hir::UnresolvedField) -> Option<Vec<Assist>> {

crates/ide-diagnostics/src/handlers/unresolved_ident.rs

@@ -13,7 +13,6 @@ pub(crate) fn unresolved_ident(
         range.range = in_node_range + range.range.start();
     }
     Diagnostic::new(DiagnosticCode::RustcHardError("E0425"), "no such value in this scope", range)
-        .experimental()
 }
 
 #[cfg(test)]