[`flake8-pyi`] Implement `PYI012` (#3743)

crates/ruff/resources/test/fixtures/flake8_pyi/PYI012.py

@@ -0,0 +1,75 @@
+# Violations of PYI012
+
+
+class OneAttributeClass:
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+
+class OneAttributeClassRev:
+    pass  # PYI012 Class body must not contain `pass`
+    value: int
+
+
+class DocstringClass:
+    """
+    My body only contains pass.
+    """
+
+    pass  # PYI012 Class body must not contain `pass`
+
+
+class NonEmptyChild(Exception):
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+
+class NonEmptyChild2(Exception):
+    pass  # PYI012 Class body must not contain `pass`
+    value: int
+
+
+class NonEmptyWithInit:
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+    def __init__():
+        pass
+
+
+# Not violations (of PYI012)
+
+
+class EmptyClass:
+    pass  # Y009 Empty body should contain `...`, not `pass`
+
+
+class EmptyOneLine:
+    pass  # Y009 Empty body should contain `...`, not `pass`
+
+
+class Dog:
+    eyes: int = 2
+
+
+class EmptyEllipsis:
+    ...
+
+
+class NonEmptyEllipsis:
+    value: int
+    ...  # Y013 Non-empty class body must not contain `...`
+
+
+class WithInit:
+    value: int = 0
+
+    def __init__():
+        pass
+
+
+def function():
+    pass
+
+
+pass

crates/ruff/resources/test/fixtures/flake8_pyi/PYI012.pyi

@@ -0,0 +1,59 @@
+# Violations of PYI012
+
+class OneAttributeClass:
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+class OneAttributeClassRev:
+    pass  # PYI012 Class body must not contain `pass`
+    value: int
+
+class DocstringClass:
+    """
+    My body only contains pass.
+    """
+
+    pass  # PYI012 Class body must not contain `pass`
+
+class NonEmptyChild(Exception):
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+class NonEmptyChild2(Exception):
+    pass  # PYI012 Class body must not contain `pass`
+    value: int
+
+class NonEmptyWithInit:
+    value: int
+    pass  # PYI012 Class body must not contain `pass`
+
+    def __init__():
+        pass
+
+# Not violations (of PYI012)
+
+class EmptyClass:
+    pass  # Y009 Empty body should contain `...`, not `pass`
+
+class EmptyOneLine:
+    pass  # Y009 Empty body should contain `...`, not `pass`
+
+class Dog:
+    eyes: int = 2
+
+class EmptyEllipsis: ...
+
+class NonEmptyEllipsis:
+    value: int
+    ...  # Y013 Non-empty class body must not contain `...`
+
+class WithInit:
+    value: int = 0
+
+    def __init__():
+        pass
+
+def function():
+    pass
+
+pass

crates/ruff/src/checkers/ast/mod.rs

@@ -775,6 +775,9 @@ where
                     if self.settings.rules.enabled(Rule::PassStatementStubBody) {
                         flake8_pyi::rules::pass_statement_stub_body(self, body);
                     }
+                    if self.settings.rules.enabled(Rule::PassInClassBody) {
+                        flake8_pyi::rules::pass_in_class_body(self, stmt, body);
+                    }
                 }
 
                 if self

crates/ruff/src/codes.rs

@@ -569,6 +569,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<Rule> {
         (Flake8Pyi, "009") => Rule::PassStatementStubBody,
         (Flake8Pyi, "010") => Rule::NonEmptyStubBody,
         (Flake8Pyi, "011") => Rule::TypedArgumentDefaultInStub,
+        (Flake8Pyi, "012") => Rule::PassInClassBody,
         (Flake8Pyi, "014") => Rule::ArgumentDefaultInStub,
         (Flake8Pyi, "015") => Rule::AssignmentDefaultInStub,
         (Flake8Pyi, "021") => Rule::DocstringInStub,

crates/ruff/src/registry.rs

@@ -525,6 +525,7 @@ ruff_macros::register_rules!(
     rules::flake8_pyi::rules::UnprefixedTypeParam,
     rules::flake8_pyi::rules::UnrecognizedPlatformCheck,
     rules::flake8_pyi::rules::UnrecognizedPlatformName,
+    rules::flake8_pyi::rules::PassInClassBody,
     // flake8-pytest-style
     rules::flake8_pytest_style::rules::PytestFixtureIncorrectParenthesesStyle,
     rules::flake8_pytest_style::rules::PytestFixturePositionalArgs,

crates/ruff/src/rules/flake8_pyi/mod.rs

@@ -27,6 +27,8 @@ mod tests {
     #[test_case(Rule::NonEmptyStubBody, Path::new("PYI010.pyi"))]
     #[test_case(Rule::TypedArgumentDefaultInStub, Path::new("PYI011.py"))]
     #[test_case(Rule::TypedArgumentDefaultInStub, Path::new("PYI011.pyi"))]
+    #[test_case(Rule::PassInClassBody, Path::new("PYI012.py"))]
+    #[test_case(Rule::PassInClassBody, Path::new("PYI012.pyi"))]
     #[test_case(Rule::ArgumentDefaultInStub, Path::new("PYI014.py"))]
     #[test_case(Rule::ArgumentDefaultInStub, Path::new("PYI014.pyi"))]
     #[test_case(Rule::AssignmentDefaultInStub, Path::new("PYI015.py"))]

crates/ruff/src/rules/flake8_pyi/rules/mod.rs

@@ -1,6 +1,7 @@
 pub use bad_version_info_comparison::{bad_version_info_comparison, BadVersionInfoComparison};
 pub use docstring_in_stubs::{docstring_in_stubs, DocstringInStub};
 pub use non_empty_stub_body::{non_empty_stub_body, NonEmptyStubBody};
+pub use pass_in_class_body::{pass_in_class_body, PassInClassBody};
 pub use pass_statement_stub_body::{pass_statement_stub_body, PassStatementStubBody};
 pub use prefix_type_params::{prefix_type_params, UnprefixedTypeParam};
 pub use simple_defaults::{
@@ -15,6 +16,7 @@ pub use unrecognized_platform::{
 mod bad_version_info_comparison;
 mod docstring_in_stubs;
 mod non_empty_stub_body;
+mod pass_in_class_body;
 mod pass_statement_stub_body;
 mod prefix_type_params;
 mod simple_defaults;

crates/ruff/src/rules/flake8_pyi/rules/pass_in_class_body.rs

@@ -0,0 +1,62 @@
+use crate::autofix::helpers::delete_stmt;
+use log::error;
+use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic};
+use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::types::{Range, RefEquality};
+
+use crate::checkers::ast::Checker;
+
+use crate::registry::AsRule;
+use rustpython_parser::ast::{Stmt, StmtKind};
+
+#[violation]
+pub struct PassInClassBody;
+
+impl AlwaysAutofixableViolation for PassInClassBody {
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        format!("Class body must not contain `pass`")
+    }
+
+    fn autofix_title(&self) -> String {
+        format!("Remove unnecessary `pass`")
+    }
+}
+
+/// PYI012
+pub fn pass_in_class_body<'a>(checker: &mut Checker<'a>, parent: &'a Stmt, body: &'a [Stmt]) {
+    // `pass` is required in these situations (or handled by `pass_statement_stub_body`).
+    if body.len() < 2 {
+        return;
+    }
+
+    for stmt in body {
+        if matches!(stmt.node, StmtKind::Pass) {
+            let mut diagnostic = Diagnostic::new(PassInClassBody, Range::from(stmt));
+
+            if checker.patch(diagnostic.kind.rule()) {
+                let deleted: Vec<&Stmt> = checker.deletions.iter().map(Into::into).collect();
+                match delete_stmt(
+                    stmt,
+                    Some(parent),
+                    &deleted,
+                    checker.locator,
+                    checker.indexer,
+                    checker.stylist,
+                ) {
+                    Ok(fix) => {
+                        if fix.content.is_empty() || fix.content == "pass" {
+                            checker.deletions.insert(RefEquality(stmt));
+                        }
+                        diagnostic.set_fix(fix);
+                    }
+                    Err(e) => {
+                        error!("Failed to delete `pass` statement: {}", e);
+                    }
+                };
+            };
+
+            checker.diagnostics.push(diagnostic);
+        }
+    }
+}

crates/ruff/src/rules/flake8_pyi/snapshots/ruff__rules__flake8_pyi__tests__PYI012_PYI012.py.snap

@@ -0,0 +1,6 @@
+---
+source: crates/ruff/src/rules/flake8_pyi/mod.rs
+expression: diagnostics
+---
+[]
+

crates/ruff/src/rules/flake8_pyi/snapshots/ruff__rules__flake8_pyi__tests__PYI012_PYI012.pyi.snap

@@ -0,0 +1,131 @@
+---
+source: crates/ruff/src/rules/flake8_pyi/mod.rs
+expression: diagnostics
+---
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 5
+    column: 4
+  end_location:
+    row: 5
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 5
+          column: 0
+        end_location:
+          row: 6
+          column: 0
+  parent: ~
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 8
+    column: 4
+  end_location:
+    row: 8
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 8
+          column: 0
+        end_location:
+          row: 9
+          column: 0
+  parent: ~
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 16
+    column: 4
+  end_location:
+    row: 16
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 16
+          column: 0
+        end_location:
+          row: 17
+          column: 0
+  parent: ~
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 20
+    column: 4
+  end_location:
+    row: 20
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 20
+          column: 0
+        end_location:
+          row: 21
+          column: 0
+  parent: ~
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 23
+    column: 4
+  end_location:
+    row: 23
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 23
+          column: 0
+        end_location:
+          row: 24
+          column: 0
+  parent: ~
+- kind:
+    name: PassInClassBody
+    body: "Class body must not contain `pass`"
+    suggestion: "Remove unnecessary `pass`"
+    fixable: true
+  location:
+    row: 28
+    column: 4
+  end_location:
+    row: 28
+    column: 8
+  fix:
+    edits:
+      - content: ""
+        location:
+          row: 28
+          column: 0
+        end_location:
+          row: 29
+          column: 0
+  parent: ~
+

ruff.schema.json

@@ -2034,6 +2034,7 @@
         "PYI01",
         "PYI010",
         "PYI011",
+        "PYI012",
         "PYI014",
         "PYI015",
         "PYI02",