feat: plugin scaffold for tryceratops with TRY300 (#2055)

Renamed to TRY to avoid conflicts, as proposed in https://github.com/guilatrova/tryceratops/pull/55

https://github.com/guilatrova/tryceratops/blob/main/docs/violations/TC300.md

See: #2056

README.md

@@ -140,6 +140,7 @@ developer of [Zulip](https://github.com/zulip/zulip):
    1. [flake8-no-pep420 (INP)](#flake8-no-pep420-inp)
    1. [flake8-executable (EXE)](#flake8-executable-exe)
    1. [flake8-type-checking (TYP)](#flake8-type-checking-typ)
+   1. [tryceratops (TRY)](#tryceratops-try)
    1. [Ruff-specific rules (RUF)](#ruff-specific-rules-ruf)<!-- End auto-generated table of contents. -->
 1. [Editor Integrations](#editor-integrations)
 1. [FAQ](#faq)
@@ -1187,6 +1188,14 @@ For more, see [flake8-type-checking](https://pypi.org/project/flake8-type-checki
 | ---- | ---- | ------- | --- |
 | TYP005 | empty-type-checking-block | Found empty type-checking block |  |
 
+### tryceratops (TRY)
+
+For more, see [tryceratops](https://pypi.org/project/tryceratops/1.1.0/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| TRY300 | try-consider-else | Consider `else` block |  |
+
 ### Ruff-specific rules (RUF)
 
 | Code | Name | Message | Fix |

resources/test/fixtures/tryceratops/TRY300.py

@@ -0,0 +1,47 @@
+"""
+Violation:
+
+Returning a final value inside a try block may indicate you could use an else block
+instead to outline the success scenario
+"""
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class MyException(Exception):
+    pass
+
+
+def bad():
+    try:
+        a = 1
+        b = process()
+        return b
+    except MyException:
+        logger.exception("process failed")
+
+
+def good():
+    try:
+        a = 1
+        b = process()
+    except MyException:
+        logger.exception("process failed")
+    else:
+        return b
+
+
+def noreturn():
+    try:
+        a = 1
+        b = process()
+    except MyException:
+        logger.exception("process failed")
+
+
+def still_good():
+    try:
+        return process()
+    except MyException:
+        logger.exception("process failed")

ruff.schema.json

@@ -1747,6 +1747,10 @@
         "TID25",
         "TID251",
         "TID252",
+        "TRY",
+        "TRY3",
+        "TRY30",
+        "TRY300",
         "TYP",
         "TYP0",
         "TYP00",

src/checkers/ast.rs

@@ -37,7 +37,7 @@ use crate::rules::{
     flake8_errmsg, flake8_implicit_str_concat, flake8_import_conventions, flake8_pie, flake8_print,
     flake8_pytest_style, flake8_return, flake8_simplify, flake8_tidy_imports, flake8_type_checking,
     flake8_unused_arguments, mccabe, pandas_vet, pep8_naming, pycodestyle, pydocstyle, pyflakes,
-    pygrep_hooks, pylint, pyupgrade, ruff,
+    pygrep_hooks, pylint, pyupgrade, ruff, tryceratops,
 };
 use crate::settings::types::PythonVersion;
 use crate::settings::{flags, Settings};
@@ -1544,6 +1544,9 @@ where
                         self, body, handlers, finalbody,
                     );
                 }
+                if self.settings.rules.enabled(&Rule::TryConsiderElse) {
+                    tryceratops::rules::try_consider_else(self, body, orelse);
+                }
             }
             StmtKind::Assign { targets, value, .. } => {
                 if self.settings.rules.enabled(&Rule::DoNotAssignLambda) {

src/registry.rs

@@ -427,6 +427,8 @@ ruff_macros::define_rule_mapping!(
     EXE005 => rules::flake8_executable::rules::ShebangNewline,
     // flake8-type-checking
     TYP005 => rules::flake8_type_checking::rules::EmptyTypeCheckingBlock,
+    // tryceratops
+    TRY300 => rules::tryceratops::rules::TryConsiderElse,
     // Ruff
     RUF001 => violations::AmbiguousUnicodeCharacterString,
     RUF002 => violations::AmbiguousUnicodeCharacterDocstring,
@@ -511,6 +513,8 @@ pub enum Linter {
     Flake8Executable,
     #[prefix = "TYP"]
     Flake8TypeChecking,
+    #[prefix = "TRY"]
+    Tryceratops,
     #[prefix = "RUF"]
     Ruff,
 }
@@ -585,6 +589,7 @@ impl Linter {
             Linter::Flake8NoPep420 => Prefixes::Single(RuleSelector::INP),
             Linter::Flake8Executable => Prefixes::Single(RuleSelector::EXE),
             Linter::Flake8TypeChecking => Prefixes::Single(RuleSelector::TYP),
+            Linter::Tryceratops => Prefixes::Single(RuleSelector::TRY),
             Linter::Ruff => Prefixes::Single(RuleSelector::RUF),
         }
     }

src/rules/mod.rs

@@ -36,3 +36,4 @@ pub mod pygrep_hooks;
 pub mod pylint;
 pub mod pyupgrade;
 pub mod ruff;
+pub mod tryceratops;

src/rules/tryceratops/mod.rs

@@ -0,0 +1,28 @@
+//! Rules from [tryceratops](https://pypi.org/project/tryceratops/1.1.0/).
+pub(crate) mod rules;
+
+#[cfg(test)]
+mod tests {
+    use std::convert::AsRef;
+    use std::path::Path;
+
+    use anyhow::Result;
+    use test_case::test_case;
+
+    use crate::linter::test_path;
+    use crate::registry::Rule;
+    use crate::settings;
+
+    #[test_case(Rule::TryConsiderElse, Path::new("TRY300.py"); "TRY300")]
+    fn rules(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
+        let diagnostics = test_path(
+            Path::new("./resources/test/fixtures/tryceratops")
+                .join(path)
+                .as_path(),
+            &settings::Settings::for_rule(rule_code),
+        )?;
+        insta::assert_yaml_snapshot!(snapshot, diagnostics);
+        Ok(())
+    }
+}

src/rules/tryceratops/rules/mod.rs

@@ -0,0 +1,3 @@
+pub use try_consider_else::{try_consider_else, TryConsiderElse};
+
+mod try_consider_else;

src/rules/tryceratops/rules/try_consider_else.rs

@@ -0,0 +1,32 @@
+use ruff_macros::derive_message_formats;
+use rustpython_ast::{Stmt, StmtKind};
+
+use crate::ast::types::Range;
+use crate::checkers::ast::Checker;
+use crate::define_violation;
+use crate::registry::Diagnostic;
+use crate::violation::Violation;
+
+define_violation!(
+    pub struct TryConsiderElse;
+);
+impl Violation for TryConsiderElse {
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        format!("Consider `else` block")
+    }
+}
+
+/// TRY300
+pub fn try_consider_else(checker: &mut Checker, body: &[Stmt], orelse: &[Stmt]) {
+    if body.len() > 1 && orelse.is_empty() {
+        if let Some(stmt) = body.last() {
+            if let StmtKind::Return { .. } = &stmt.node {
+                checker.diagnostics.push(Diagnostic::new(
+                    TryConsiderElse,
+                    Range::from_located(&body[0]),
+                ));
+            }
+        }
+    }
+}

src/rules/tryceratops/snapshots/ruff__rules__tryceratops__tests__try-consider-else_TRY300.py.snap

@@ -0,0 +1,14 @@
+---
+source: src/rules/tryceratops/mod.rs
+expression: diagnostics
+---
+- kind:
+    TryConsiderElse: ~
+  location:
+    row: 18
+    column: 8
+  end_location:
+    row: 18
+    column: 13
+  fix: ~
+  parent: ~