Enhance BLE001: fix docs; light speed-up; improve readability

Author: deliro

crates/ruff_linter/resources/test/fixtures/flake8_blind_except/BLE.py

@@ -154,6 +154,11 @@
 except Exception as e:
     raise ValueError from e
 
+try:
+    ...
+except Exception as e:
+    raise e from ValueError("hello")
+
 
 try:
     pass
@@ -245,3 +250,9 @@
     pass
 except (Exception, ValueError) as e:
     raise e
+
+# `from None` cause
+try:
+    pass
+except BaseException as e:
+    raise e from None

crates/ruff_linter/src/rules/flake8_blind_except/rules/blind_except.rs

@@ -11,7 +11,7 @@ use crate::checkers::ast::Checker;
 
 /// ## What it does
 /// Checks for `except` clauses that catch all exceptions.  This includes
-/// bare `except`, `except BaseException` and `except Exception`.
+/// `except BaseException` and `except Exception`.
 ///
 ///
 /// ## Why is this bad?
@@ -149,24 +149,28 @@ impl<'a> ReraiseVisitor<'a> {
 
 impl<'a> StatementVisitor<'a> for ReraiseVisitor<'a> {
     fn visit_stmt(&mut self, stmt: &'a Stmt) {
+        if self.seen {
+            return;
+        }
         match stmt {
             Stmt::Raise(ast::StmtRaise { exc, cause, .. }) => {
-                if let Some(cause) = cause {
-                    if let Expr::Name(ast::ExprName { id, .. }) = cause.as_ref() {
-                        if self.name.is_some_and(|name| id == name) {
-                            self.seen = true;
-                        }
+                // except Exception [as <name>]:
+                //     raise [<exc> [from <cause>]]
+                let reraised = match (self.name, exc.as_deref(), cause.as_deref()) {
+                    // `raise`
+                    (_, None, None) => true,
+                    // `raise SomeExc from <name>`
+                    (Some(name), _, Some(Expr::Name(ast::ExprName { id, .. }))) if name == id => {
+                        true
                     }
-                } else {
-                    if let Some(exc) = exc {
-                        if let Expr::Name(ast::ExprName { id, .. }) = exc.as_ref() {
-                            if self.name.is_some_and(|name| id == name) {
-                                self.seen = true;
-                            }
-                        }
-                    } else {
-                        self.seen = true;
+                    // `raise <name>` and `raise <name> from SomeCause`
+                    (Some(name), Some(Expr::Name(ast::ExprName { id, .. })), _) if name == id => {
+                        true
                     }
+                    _ => false,
+                };
+                if reraised {
+                    self.seen = true;
                 }
             }
             Stmt::Try(_) | Stmt::FunctionDef(_) | Stmt::ClassDef(_) => {}
@@ -200,6 +204,9 @@ impl<'a> LogExceptionVisitor<'a> {
 
 impl<'a> StatementVisitor<'a> for LogExceptionVisitor<'a> {
     fn visit_stmt(&mut self, stmt: &'a Stmt) {
+        if self.seen {
+            return;
+        }
         match stmt {
             Stmt::Expr(ast::StmtExpr { value, .. }) => {
                 if let Expr::Call(ast::ExprCall {

crates/ruff_linter/src/rules/flake8_blind_except/snapshots/ruff_linter__rules__flake8_blind_except__tests__BLE001_BLE.py.snap

@@ -148,92 +148,92 @@ BLE.py:131:8: BLE001 Do not catch blind exception: `Exception`
 132 |     critical("...", exc_info=None)
     |
 
-BLE.py:169:9: BLE001 Do not catch blind exception: `Exception`
-    |
-167 | try:
-168 |     pass
-169 | except (Exception,):
-    |         ^^^^^^^^^ BLE001
-170 |     pass
-    |
-
 BLE.py:174:9: BLE001 Do not catch blind exception: `Exception`
     |
 172 | try:
 173 |     pass
-174 | except (Exception, ValueError):
+174 | except (Exception,):
     |         ^^^^^^^^^ BLE001
 175 |     pass
     |
 
-BLE.py:179:21: BLE001 Do not catch blind exception: `Exception`
+BLE.py:179:9: BLE001 Do not catch blind exception: `Exception`
     |
 177 | try:
 178 |     pass
-179 | except (ValueError, Exception):
-    |                     ^^^^^^^^^ BLE001
+179 | except (Exception, ValueError):
+    |         ^^^^^^^^^ BLE001
 180 |     pass
     |
 
 BLE.py:184:21: BLE001 Do not catch blind exception: `Exception`
     |
 182 | try:
 183 |     pass
-184 | except (ValueError, Exception) as e:
+184 | except (ValueError, Exception):
     |                     ^^^^^^^^^ BLE001
-185 |     print(e)
+185 |     pass
     |
 
-BLE.py:189:9: BLE001 Do not catch blind exception: `BaseException`
+BLE.py:189:21: BLE001 Do not catch blind exception: `Exception`
     |
 187 | try:
 188 |     pass
-189 | except (BaseException, TypeError):
-    |         ^^^^^^^^^^^^^ BLE001
-190 |     pass
+189 | except (ValueError, Exception) as e:
+    |                     ^^^^^^^^^ BLE001
+190 |     print(e)
     |
 
-BLE.py:194:20: BLE001 Do not catch blind exception: `BaseException`
+BLE.py:194:9: BLE001 Do not catch blind exception: `BaseException`
     |
 192 | try:
 193 |     pass
-194 | except (TypeError, BaseException):
-    |                    ^^^^^^^^^^^^^ BLE001
+194 | except (BaseException, TypeError):
+    |         ^^^^^^^^^^^^^ BLE001
 195 |     pass
     |
 
-BLE.py:199:9: BLE001 Do not catch blind exception: `Exception`
+BLE.py:199:20: BLE001 Do not catch blind exception: `BaseException`
     |
 197 | try:
 198 |     pass
-199 | except (Exception, BaseException):
-    |         ^^^^^^^^^ BLE001
+199 | except (TypeError, BaseException):
+    |                    ^^^^^^^^^^^^^ BLE001
 200 |     pass
     |
 
-BLE.py:204:9: BLE001 Do not catch blind exception: `BaseException`
+BLE.py:204:9: BLE001 Do not catch blind exception: `Exception`
     |
 202 | try:
 203 |     pass
-204 | except (BaseException, Exception):
-    |         ^^^^^^^^^^^^^ BLE001
+204 | except (Exception, BaseException):
+    |         ^^^^^^^^^ BLE001
 205 |     pass
     |
 
-BLE.py:210:10: BLE001 Do not catch blind exception: `Exception`
+BLE.py:209:9: BLE001 Do not catch blind exception: `BaseException`
     |
-208 | try:
-209 |     pass
-210 | except ((Exception, ValueError), TypeError):
-    |          ^^^^^^^^^ BLE001
-211 |     pass
+207 | try:
+208 |     pass
+209 | except (BaseException, Exception):
+    |         ^^^^^^^^^^^^^ BLE001
+210 |     pass
     |
 
-BLE.py:215:22: BLE001 Do not catch blind exception: `BaseException`
+BLE.py:215:10: BLE001 Do not catch blind exception: `Exception`
     |
 213 | try:
 214 |     pass
-215 | except (ValueError, (BaseException, TypeError)):
-    |                      ^^^^^^^^^^^^^ BLE001
+215 | except ((Exception, ValueError), TypeError):
+    |          ^^^^^^^^^ BLE001
 216 |     pass
     |
+
+BLE.py:220:22: BLE001 Do not catch blind exception: `BaseException`
+    |
+218 | try:
+219 |     pass
+220 | except (ValueError, (BaseException, TypeError)):
+    |                      ^^^^^^^^^^^^^ BLE001
+221 |     pass
+    |