Upgrade to Rust 1.86 and bump MSRV to 1.84

Cargo.toml

@@ -4,7 +4,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.83"
+rust-version = "1.84"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -209,6 +209,7 @@ must_use_candidate = "allow"
 similar_names = "allow"
 single_match_else = "allow"
 too_many_lines = "allow"
+needless_continue = "allow"       # An explicit continue can be more readable, especially if the alternative is an empty block.
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
@@ -227,6 +228,10 @@ redundant_clone = "warn"
 debug_assert_with_mut_call = "warn"
 unused_peekable = "warn"
 
+# Has false positives
+# https://github.com/rust-lang/rust-clippy/issues/14275
+doc_overindented_list_items = "allow"
+
 # Diagnostics are not actionable: Enable once https://github.com/rust-lang/rust-clippy/issues/13774 is resolved.
 large_stack_arrays = "allow"
 

crates/red_knot_project/src/db.rs

@@ -159,7 +159,7 @@ impl salsa::Database for ProjectDatabase {
         }
 
         let event = event();
-        if matches!(event.kind, salsa::EventKind::WillCheckCancellation { .. }) {
+        if matches!(event.kind, salsa::EventKind::WillCheckCancellation) {
             return;
         }
 

crates/red_knot_project/src/db/changes.rs

@@ -187,7 +187,7 @@ impl ProjectDatabase {
                     let program = Program::get(self);
                     if let Err(error) = program.update_from_settings(self, program_settings) {
                         tracing::error!("Failed to update the program settings, keeping the old program settings: {error}");
-                    };
+                    }
 
                     if metadata.root() == project.root(self) {
                         tracing::debug!("Reloading project after structural change");

crates/red_knot_python_semantic/src/module_resolver/typeshed.rs

@@ -322,6 +322,7 @@ fn python_version_from_versions_file_string(
 
 #[cfg(test)]
 mod tests {
+    use std::fmt::Write as _;
     use std::num::{IntErrorKind, NonZeroU16};
     use std::path::Path;
 
@@ -333,8 +334,7 @@ mod tests {
 
     const TYPESHED_STDLIB_DIR: &str = "stdlib";
 
-    #[allow(unsafe_code)]
-    const ONE: Option<NonZeroU16> = Some(unsafe { NonZeroU16::new_unchecked(1) });
+    const ONE: Option<NonZeroU16> = Some(NonZeroU16::new(1).unwrap());
 
     impl TypeshedVersions {
         #[must_use]
@@ -571,7 +571,7 @@ foo: 3.8-   # trailing comment
 
         let mut massive_versions_file = String::new();
         for i in 0..too_many {
-            massive_versions_file.push_str(&format!("x{i}: 3.8-\n"));
+            let _ = writeln!(&mut massive_versions_file, "x{i}: 3.8-");
         }
 
         assert_eq!(

crates/red_knot_python_semantic/src/semantic_index/builder.rs

@@ -1448,7 +1448,7 @@ where
                 self.visit_expr(subject);
                 if cases.is_empty() {
                     return;
-                };
+                }
 
                 let after_subject = self.flow_snapshot();
                 let mut vis_constraints = vec![];

crates/red_knot_python_semantic/src/suppression.rs

@@ -145,7 +145,7 @@ pub(crate) fn check_suppressions(db: &dyn Db, file: File, diagnostics: &mut Type
 fn check_unknown_rule(context: &mut CheckSuppressionsContext) {
     if context.is_lint_disabled(&UNKNOWN_RULE) {
         return;
-    };
+    }
 
     for unknown in &context.suppressions.unknown {
         match &unknown.reason {
@@ -174,7 +174,7 @@ fn check_unknown_rule(context: &mut CheckSuppressionsContext) {
                     format_args!("Unknown rule `{prefixed}`. Did you mean `{suggestion}`?"),
                 );
             }
-        };
+        }
     }
 }
 
@@ -267,7 +267,7 @@ fn check_unused_suppressions(context: &mut CheckSuppressionsContext) {
                 suppression.range,
                 format_args!("Unused `{kind}` without a code", kind = suppression.kind),
             ),
-        };
+        }
     }
 }
 

crates/red_knot_python_semantic/src/symbol.rs

@@ -657,7 +657,7 @@ fn symbol_from_bindings_impl<'db>(
             binding,
             visibility_constraint,
             narrowing_constraint: _,
-        }) if binding.map_or(true, is_non_exported) => {
+        }) if binding.is_none_or(is_non_exported) => {
             visibility_constraints.evaluate(db, predicates, *visibility_constraint)
         }
         _ => Truthiness::AlwaysFalse,
@@ -794,7 +794,7 @@ fn symbol_from_declarations_impl<'db>(
         Some(DeclarationWithConstraint {
             declaration,
             visibility_constraint,
-        }) if declaration.map_or(true, is_non_exported) => {
+        }) if declaration.is_none_or(is_non_exported) => {
             visibility_constraints.evaluate(db, predicates, *visibility_constraint)
         }
         _ => Truthiness::AlwaysFalse,

crates/red_knot_python_semantic/src/types/call/bind.rs

@@ -502,13 +502,13 @@ impl<'db> Bindings<'db> {
                             if let Some(len_ty) = first_arg.len(db) {
                                 overload.set_return_type(len_ty);
                             }
-                        };
+                        }
                     }
 
                     Some(KnownFunction::Repr) => {
                         if let [Some(first_arg)] = overload.parameter_types() {
                             overload.set_return_type(first_arg.repr(db));
-                        };
+                        }
                     }
 
                     Some(KnownFunction::Cast) => {

crates/red_knot_python_semantic/src/types/infer.rs

@@ -985,7 +985,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                     Some(KnownClass::Float | KnownClass::Int | KnownClass::Bool)
                 ) => {}
             _ => return false,
-        };
+        }
 
         let (op, by_zero) = match op {
             ast::Operator::Div => ("divide", "by zero"),
@@ -1036,7 +1036,7 @@ impl<'db> TypeInferenceBuilder<'db> {
             report_invalid_assignment(&self.context, node, declared_ty, bound_ty);
             // allow declarations to override inference in case of invalid assignment
             bound_ty = declared_ty;
-        };
+        }
 
         self.types.bindings.insert(binding, bound_ty);
     }
@@ -2216,7 +2216,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                 }
             }
             ast::Pattern::MatchStar(_) | ast::Pattern::MatchSingleton(_) => {}
-        };
+        }
     }
 
     fn infer_assignment_statement(&mut self, assignment: &ast::StmtAssign) {
@@ -3242,7 +3242,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                 &DeclaredAndInferredType::AreTheSame(ty),
             );
             return;
-        };
+        }
 
         // If the module doesn't bind the symbol, check if it's a submodule.  This won't get
         // handled by the `Type::member` call because it relies on the semantic index's
@@ -4044,7 +4044,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                                                 parameter_ty=parameter_ty.display(self.db())
                                             ),
                                         );
-                                    };
+                                    }
                                 }
                             }
                         }
@@ -4895,7 +4895,7 @@ impl<'db> TypeInferenceBuilder<'db> {
 
                     if done {
                         return Type::Never;
-                    };
+                    }
 
                     match (truthiness, op) {
                         (Truthiness::AlwaysTrue, ast::BoolOp::And) => Type::Never,
@@ -5815,7 +5815,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                     Err(CallDunderError::MethodNotAvailable) => {
                         // try `__class_getitem__`
                     }
-                };
+                }
 
                 // Otherwise, if the value is itself a class and defines `__class_getitem__`,
                 // return its return type.

crates/red_knot_python_semantic/src/types/slots.rs

@@ -30,7 +30,7 @@ impl SlotsKind {
 
         if matches!(bound, Boundness::PossiblyUnbound) {
             return Self::Dynamic;
-        };
+        }
 
         match slots_ty {
             // __slots__ = ("a", "b")
@@ -98,6 +98,6 @@ pub(super) fn check_class_slots(context: &InferContext, class: Class, node: &ast
         if let Some(index) = first_with_solid_base {
             let base_node = &node.bases()[index];
             report_base_with_incompatible_slots(context, base_node);
-        };
+        }
     }
 }

crates/red_knot_python_semantic/src/types/unpacker.rs

@@ -116,8 +116,10 @@ impl<'db> Unpacker<'db> {
                             // it's worth it.
                             TupleType::from_elements(
                                 self.db(),
-                                std::iter::repeat(Type::LiteralString)
-                                    .take(string_literal_ty.python_len(self.db())),
+                                std::iter::repeat_n(
+                                    Type::LiteralString,
+                                    string_literal_ty.python_len(self.db()),
+                                ),
                             )
                         }
                         _ => ty,

crates/red_knot_test/src/assertion.rs

@@ -131,7 +131,7 @@ impl<'a> Iterator for AssertionWithRangeIterator<'a> {
             let comment = &self.file_assertions.source[inner_next];
             if let Some(assertion) = UnparsedAssertion::from_comment(comment) {
                 return Some(AssertionWithRange(assertion, inner_next));
-            };
+            }
         }
     }
 }

crates/red_knot_test/src/lib.rs

@@ -265,13 +265,13 @@ fn run_test(
                     match info.location {
                         Some(location) => messages.push(format!("panicked at {location}")),
                         None => messages.push("panicked at unknown location".to_string()),
-                    };
+                    }
                     match info.payload {
                         Some(payload) => messages.push(payload),
                         // Mimic the default panic hook's rendering of the panic payload if it's
                         // not a string.
                         None => messages.push("Box<dyn Any>".to_string()),
-                    };
+                    }
                     if let Some(backtrace) = info.backtrace {
                         if std::env::var("RUST_BACKTRACE").is_ok() {
                             messages.extend(backtrace.to_string().split('\n').map(String::from));

crates/red_knot_test/src/parser.rs

@@ -673,7 +673,7 @@ impl<'s> Parser<'s> {
                         "Test `{test_name}` has duplicate files named `{}`.",
                         path.as_str(),
                     );
-                };
+                }
 
                 if has_explicit_file_paths {
                     bail!("Merged snippets in test `{test_name}` are not allowed in the presence of other files.");

crates/ruff/src/args.rs

@@ -1,5 +1,5 @@
 use std::cmp::Ordering;
-use std::fmt::Formatter;
+use std::fmt::{Formatter, Write as _};
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
@@ -974,12 +974,13 @@ A `--config` flag must either be a path to a `.toml` configuration file
             .is_some_and(|ext| ext.eq_ignore_ascii_case("toml"))
         {
             if !value.contains('=') {
-                tip.push_str(&format!(
+                let _ = write!(
+                    &mut tip,
                     "
 
 It looks like you were trying to pass a path to a configuration file.
 The path `{value}` does not point to a configuration file"
-                ));
+                );
             }
         } else if let Some((key, value)) = value.split_once('=') {
             let key = key.trim_ascii();
@@ -993,7 +994,8 @@ The path `{value}` does not point to a configuration file"
                         .map(|(name, _)| format!("- `{key}.{name}`"))
                         .join("\n");
 
-                    tip.push_str(&format!(
+                    let _ = write!(
+                        &mut tip,
                         "
 
 `{key}` is a table of configuration options.
@@ -1002,13 +1004,14 @@ Did you want to override one of the table's subkeys?
 Possible choices:
 
 {prefixed_subfields}"
-                    ));
+                    );
                 }
                 _ => {
-                    tip.push_str(&format!(
+                    let _ = write!(
+                        &mut tip,
                         "\n\n{}:\n\n{underlying_error}",
                         config_parse_error.description()
-                    ));
+                    );
                 }
             }
         }

crates/ruff/src/commands/rule.rs

@@ -1,3 +1,4 @@
+use std::fmt::Write as _;
 use std::io::{self, BufWriter, Write};
 
 use anyhow::Result;
@@ -43,12 +44,16 @@ impl<'a> Explanation<'a> {
 
 fn format_rule_text(rule: Rule) -> String {
     let mut output = String::new();
-    output.push_str(&format!("# {} ({})", rule.as_ref(), rule.noqa_code()));
+    let _ = write!(&mut output, "# {} ({})", rule.as_ref(), rule.noqa_code());
     output.push('\n');
     output.push('\n');
 
     let (linter, _) = Linter::parse_code(&rule.noqa_code().to_string()).unwrap();
-    output.push_str(&format!("Derived from the **{}** linter.", linter.name()));
+    let _ = write!(
+        &mut output,
+        "Derived from the **{}** linter.",
+        linter.name()
+    );
     output.push('\n');
     output.push('\n');
 
@@ -76,7 +81,7 @@ fn format_rule_text(rule: Rule) -> String {
         output.push_str("Message formats:");
         for format in rule.message_formats() {
             output.push('\n');
-            output.push_str(&format!("* {format}"));
+            let _ = write!(&mut output, "* {format}");
         }
     }
     output
@@ -92,7 +97,7 @@ pub(crate) fn rule(rule: Rule, format: HelpFormat) -> Result<()> {
         HelpFormat::Json => {
             serde_json::to_writer_pretty(stdout, &Explanation::from_rule(&rule))?;
         }
-    };
+    }
     Ok(())
 }
 

crates/ruff/src/commands/version.rs

@@ -16,6 +16,6 @@ pub(crate) fn version(output_format: HelpFormat) -> Result<()> {
         HelpFormat::Json => {
             serde_json::to_writer_pretty(stdout, &version_info)?;
         }
-    };
+    }
     Ok(())
 }

crates/ruff/src/main.rs

@@ -31,7 +31,7 @@ pub fn main() -> ExitCode {
 
     // support FORCE_COLOR env var
     if let Some(force_color) = std::env::var_os("FORCE_COLOR") {
-        if force_color.len() > 0 {
+        if !force_color.is_empty() {
             colored::control::set_override(true);
         }
     }

crates/ruff_annotate_snippets/src/renderer/display_list.rs

@@ -315,7 +315,7 @@ impl DisplaySet<'_> {
                         None => {
                             buffer.putc(line_offset, lineno_width + 1, '|', *lineno_color);
                         }
-                    };
+                    }
                 }
                 if let DisplaySourceLine::Content { text, .. } = line {
                     // The width of the line number, a space, pipe, and a space
@@ -1753,7 +1753,7 @@ fn format_inline_marks(
             DisplayMarkType::AnnotationThrough(depth) => {
                 buf.putc(line, 3 + lineno_width + depth, '|', *annotation_style);
             }
-        };
+        }
     }
     Ok(())
 }