Use a derive macro for Violations (#14557)

Co-authored-by: Alex Waygood <[email protected]>

CONTRIBUTING.md

@@ -139,7 +139,7 @@ At a high level, the steps involved in adding a new lint rule are as follows:
 1. Create a file for your rule (e.g., `crates/ruff_linter/src/rules/flake8_bugbear/rules/assert_false.rs`).
 
 1. In that file, define a violation struct (e.g., `pub struct AssertFalse`). You can grep for
-    `#[violation]` to see examples.
+    `#[derive(ViolationMetadata)]` to see examples.
 
 1. In that file, define a function that adds the violation to the diagnostic list as appropriate
     (e.g., `pub(crate) fn assert_false`) based on whatever inputs are required for the rule (e.g.,

clippy.toml

@@ -1,21 +1,25 @@
 doc-valid-idents = [
-  "..",
-  "CodeQL",
-  "FastAPI",
-  "IPython",
-  "LangChain",
-  "LibCST",
-  "McCabe",
-  "NumPy",
-  "SCREAMING_SNAKE_CASE",
-  "SQLAlchemy",
-  "StackOverflow",
-  "PyCharm",
+    "..",
+    "CodeQL",
+    "FastAPI",
+    "IPython",
+    "LangChain",
+    "LibCST",
+    "McCabe",
+    "NumPy",
+    "SCREAMING_SNAKE_CASE",
+    "SQLAlchemy",
+    "StackOverflow",
+    "PyCharm",
+    "SNMPv1",
+    "SNMPv2",
+    "SNMPv3",
+    "PyFlakes"
 ]
 
 ignore-interior-mutability = [
-  # Interned is read-only. The wrapped `Rc` never gets updated.
-  "ruff_formatter::format_element::Interned",
-  # The expression is read-only.
-  "ruff_python_ast::hashable::HashableExpr",
+    # Interned is read-only. The wrapped `Rc` never gets updated.
+    "ruff_formatter::format_element::Interned",
+    # The expression is read-only.
+    "ruff_python_ast::hashable::HashableExpr",
 ]

crates/ruff_diagnostics/src/lib.rs

@@ -2,7 +2,7 @@ pub use diagnostic::{Diagnostic, DiagnosticKind};
 pub use edit::Edit;
 pub use fix::{Applicability, Fix, IsolationLevel};
 pub use source_map::{SourceMap, SourceMarker};
-pub use violation::{AlwaysFixableViolation, FixAvailability, Violation};
+pub use violation::{AlwaysFixableViolation, FixAvailability, Violation, ViolationMetadata};
 
 mod diagnostic;
 mod edit;

crates/ruff_diagnostics/src/violation.rs

@@ -1,3 +1,4 @@
+use crate::DiagnosticKind;
 use std::fmt::{Debug, Display};
 
 #[derive(Debug, Copy, Clone)]
@@ -17,7 +18,16 @@ impl Display for FixAvailability {
     }
 }
 
-pub trait Violation: Debug + PartialEq + Eq {
+pub trait ViolationMetadata {
+    /// Returns the rule name of this violation
+    fn rule_name() -> &'static str;
+
+    /// Returns an explanation of what this violation catches,
+    /// why it's bad, and what users should do instead.
+    fn explain() -> Option<&'static str>;
+}
+
+pub trait Violation: ViolationMetadata {
     /// `None` in the case a fix is never available or otherwise Some
     /// [`FixAvailability`] describing the available fix.
     const FIX_AVAILABILITY: FixAvailability = FixAvailability::None;
@@ -41,7 +51,7 @@ pub trait Violation: Debug + PartialEq + Eq {
 
 /// This trait exists just to make implementing the [`Violation`] trait more
 /// convenient for violations that can always be fixed.
-pub trait AlwaysFixableViolation: Debug + PartialEq + Eq {
+pub trait AlwaysFixableViolation: ViolationMetadata {
     /// The message used to describe the violation.
     fn message(&self) -> String;
 
@@ -69,3 +79,16 @@ impl<V: AlwaysFixableViolation> Violation for V {
         <Self as AlwaysFixableViolation>::message_formats()
     }
 }
+
+impl<T> From<T> for DiagnosticKind
+where
+    T: Violation,
+{
+    fn from(value: T) -> Self {
+        Self {
+            body: Violation::message(&value),
+            suggestion: Violation::fix_title(&value),
+            name: T::rule_name().to_string(),
+        }
+    }
+}

crates/ruff_linter/src/rules/airflow/rules/dag_schedule_argument.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::Expr;
 use ruff_python_ast::{self as ast};
 use ruff_python_semantic::Modules;
@@ -39,8 +39,8 @@ use crate::checkers::ast::Checker;
 ///
 /// dag = DAG(dag_id="my_dag", schedule=timedelta(days=1))
 /// ```
-#[violation]
-pub struct AirflowDagNoScheduleArgument;
+#[derive(ViolationMetadata)]
+pub(crate) struct AirflowDagNoScheduleArgument;
 
 impl Violation for AirflowDagNoScheduleArgument {
     #[derive_message_formats]

crates/ruff_linter/src/rules/airflow/rules/task_variable_name.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast as ast;
 use ruff_python_ast::Expr;
 use ruff_python_semantic::Modules;
@@ -31,8 +31,8 @@ use crate::checkers::ast::Checker;
 ///
 /// my_task = PythonOperator(task_id="my_task")
 /// ```
-#[violation]
-pub struct AirflowVariableNameTaskIdMismatch {
+#[derive(ViolationMetadata)]
+pub(crate) struct AirflowVariableNameTaskIdMismatch {
     task_id: String,
 }
 

crates/ruff_linter/src/rules/eradicate/rules/commented_out_code.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_trivia::CommentRanges;
 use ruff_source_file::{LineRanges, UniversalNewlineIterator};
 use ruff_text_size::TextRange;
@@ -29,8 +29,8 @@ use super::super::detection::comment_contains_code;
 /// - `lint.task-tags`
 ///
 /// [#4845]: https://github.com/astral-sh/ruff/issues/4845
-#[violation]
-pub struct CommentedOutCode;
+#[derive(ViolationMetadata)]
+pub(crate) struct CommentedOutCode;
 
 impl Violation for CommentedOutCode {
     const FIX_AVAILABILITY: FixAvailability = FixAvailability::None;

crates/ruff_linter/src/rules/fastapi/rules/fastapi_non_annotated_dependency.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast as ast;
 use ruff_python_ast::helpers::map_callable;
 use ruff_python_semantic::Modules;
@@ -63,8 +63,8 @@ use crate::settings::types::PythonVersion;
 /// [fastAPI documentation]: https://fastapi.tiangolo.com/tutorial/query-params-str-validations/?h=annotated#advantages-of-annotated
 /// [typing.Annotated]: https://docs.python.org/3/library/typing.html#typing.Annotated
 /// [typing_extensions]: https://typing-extensions.readthedocs.io/en/stable/
-#[violation]
-pub struct FastApiNonAnnotatedDependency {
+#[derive(ViolationMetadata)]
+pub(crate) struct FastApiNonAnnotatedDependency {
     py_version: PythonVersion,
 }
 

crates/ruff_linter/src/rules/fastapi/rules/fastapi_redundant_response_model.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Fix};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::{Decorator, Expr, ExprCall, Keyword, StmtFunctionDef};
 use ruff_python_semantic::{Modules, SemanticModel};
 use ruff_text_size::Ranged;
@@ -59,8 +59,8 @@ use crate::rules::fastapi::rules::is_fastapi_route_decorator;
 ///     return item
 /// ```
 
-#[violation]
-pub struct FastApiRedundantResponseModel;
+#[derive(ViolationMetadata)]
+pub(crate) struct FastApiRedundantResponseModel;
 
 impl AlwaysFixableViolation for FastApiRedundantResponseModel {
     #[derive_message_formats]

crates/ruff_linter/src/rules/fastapi/rules/fastapi_unused_path_parameter.rs

@@ -4,7 +4,7 @@ use std::str::CharIndices;
 
 use ruff_diagnostics::Fix;
 use ruff_diagnostics::{Diagnostic, FixAvailability, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast as ast;
 use ruff_python_ast::{Expr, Parameter, ParameterWithDefault};
 use ruff_python_semantic::{Modules, SemanticModel};
@@ -62,8 +62,8 @@ use crate::rules::fastapi::rules::is_fastapi_route_decorator;
 /// ## Fix safety
 /// This rule's fix is marked as unsafe, as modifying a function signature can
 /// change the behavior of the code.
-#[violation]
-pub struct FastApiUnusedPathParameter {
+#[derive(ViolationMetadata)]
+pub(crate) struct FastApiUnusedPathParameter {
     arg_name: String,
     function_name: String,
     is_positional: bool,

crates/ruff_linter/src/rules/flake8_2020/rules/compare.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::{self as ast, CmpOp, Expr};
 use ruff_text_size::Ranged;
 
@@ -40,8 +40,8 @@ use super::super::helpers::is_sys;
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionCmpStr3;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionCmpStr3;
 
 impl Violation for SysVersionCmpStr3 {
     #[derive_message_formats]
@@ -87,8 +87,8 @@ impl Violation for SysVersionCmpStr3 {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionInfo0Eq3;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionInfo0Eq3;
 
 impl Violation for SysVersionInfo0Eq3 {
     #[derive_message_formats]
@@ -127,8 +127,8 @@ impl Violation for SysVersionInfo0Eq3 {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionInfo1CmpInt;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionInfo1CmpInt;
 
 impl Violation for SysVersionInfo1CmpInt {
     #[derive_message_formats]
@@ -169,8 +169,8 @@ impl Violation for SysVersionInfo1CmpInt {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionInfoMinorCmpInt;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionInfoMinorCmpInt;
 
 impl Violation for SysVersionInfoMinorCmpInt {
     #[derive_message_formats]
@@ -212,8 +212,8 @@ impl Violation for SysVersionInfoMinorCmpInt {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionCmpStr10;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionCmpStr10;
 
 impl Violation for SysVersionCmpStr10 {
     #[derive_message_formats]

crates/ruff_linter/src/rules/flake8_2020/rules/name_or_attribute.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::Expr;
 use ruff_python_semantic::Modules;
 use ruff_text_size::Ranged;
@@ -35,8 +35,8 @@ use crate::checkers::ast::Checker;
 /// - [PyPI: `six`](https://pypi.org/project/six/)
 /// - [Six documentation: `six.PY2`](https://six.readthedocs.io/#six.PY2)
 /// - [Six documentation: `six.PY3`](https://six.readthedocs.io/#six.PY3)
-#[violation]
-pub struct SixPY3;
+#[derive(ViolationMetadata)]
+pub(crate) struct SixPY3;
 
 impl Violation for SixPY3 {
     #[derive_message_formats]

crates/ruff_linter/src/rules/flake8_2020/rules/subscript.rs

@@ -1,5 +1,5 @@
 use ruff_diagnostics::{Diagnostic, Violation};
-use ruff_macros::{derive_message_formats, violation};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::{self as ast, Expr};
 use ruff_text_size::Ranged;
 
@@ -37,8 +37,8 @@ use crate::rules::flake8_2020::helpers::is_sys;
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionSlice3;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionSlice3;
 
 impl Violation for SysVersionSlice3 {
     #[derive_message_formats]
@@ -77,8 +77,8 @@ impl Violation for SysVersionSlice3 {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersion2;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersion2;
 
 impl Violation for SysVersion2 {
     #[derive_message_formats]
@@ -117,8 +117,8 @@ impl Violation for SysVersion2 {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersion0;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersion0;
 
 impl Violation for SysVersion0 {
     #[derive_message_formats]
@@ -157,8 +157,8 @@ impl Violation for SysVersion0 {
 /// ## References
 /// - [Python documentation: `sys.version`](https://docs.python.org/3/library/sys.html#sys.version)
 /// - [Python documentation: `sys.version_info`](https://docs.python.org/3/library/sys.html#sys.version_info)
-#[violation]
-pub struct SysVersionSlice1;
+#[derive(ViolationMetadata)]
+pub(crate) struct SysVersionSlice1;
 
 impl Violation for SysVersionSlice1 {
     #[derive_message_formats]