Implement pyupgrade check for io.open alias (#1399)

CONTRIBUTING.md

@@ -80,7 +80,7 @@ Then, run `cargo test`. Your test will fail, but you'll be prompted to follow-up
 rest of your changes.
 
 Finally, to update the documentation, run `cargo dev generate-rules-table` from the repo root. To
-update the generated prefix map, run `cargo dev generate-check-code-prefix`. Both of these commands
+update the generated prefix map, run `cargo +nightly dev generate-check-code-prefix`. Both of these commands
 should be run whenever a new check is added to the codebase.
 
 ### Example: Adding a new configuration option

README.md

@@ -659,6 +659,7 @@ For more, see [pyupgrade](https://pypi.org/project/pyupgrade/3.2.0/) on PyPI.
 | UP017 | DatetimeTimezoneUTC | Use `datetime.UTC` alias | 🛠 |
 | UP018 | NativeLiterals | Unnecessary call to `str` and `bytes` | 🛠 |
 | UP019 | TypingTextStrAlias | `typing.Text` is deprecated, use `str` | 🛠 |
+| UP020 | OpenAlias | Use builtin `open` instead | 🛠 |
 
 ### pep8-naming (N)
 
@@ -1262,7 +1263,7 @@ natively, including:
 - [`pep8-naming`](https://pypi.org/project/pep8-naming/)
 - [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 - [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (3/10)
-- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (19/33)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (20/33)
 - [`yesqa`](https://github.com/asottile/yesqa)
 
 Note that, in some cases, Ruff uses different error code prefixes than would be found in the
@@ -1319,7 +1320,7 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 Ruff can also replace [`isort`](https://pypi.org/project/isort/),
 [`yesqa`](https://github.com/asottile/yesqa), [`eradicate`](https://pypi.org/project/eradicate/),
 [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (3/10), and a subset of the rules
-implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (19/33).
+implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (20/33).
 
 If you're looking to use Ruff, but rely on an unsupported Flake8 plugin, free to file an Issue.
 

resources/test/fixtures/pyupgrade/UP020.py

@@ -0,0 +1,9 @@
+from io import open
+
+with open("f.txt") as f:
+    print(f.read())
+
+import io
+
+with io.open("f.txt", mode="r", buffering=-1, **kwargs) as f:
+    print(f.read())

ruff.schema.json

@@ -865,6 +865,8 @@
         "UP017",
         "UP018",
         "UP019",
+        "UP02",
+        "UP020",
         "W",
         "W2",
         "W29",

src/checkers/ast.rs

@@ -1926,6 +1926,10 @@ where
                     pyupgrade::plugins::redundant_open_modes(self, expr);
                 }
 
+                if self.settings.enabled.contains(&CheckCode::UP020) {
+                    pyupgrade::plugins::open_alias(self, expr, func);
+                }
+
                 // flake8-boolean-trap
                 if self.settings.enabled.contains(&CheckCode::FBT003) {
                     flake8_boolean_trap::plugins::check_boolean_positional_value_in_function_call(

src/checks.rs

@@ -227,6 +227,7 @@ pub enum CheckCode {
     UP017,
     UP018,
     UP019,
+    UP020,
     // pydocstyle
     D100,
     D101,
@@ -839,6 +840,7 @@ pub enum CheckKind {
     RemoveSixCompat,
     DatetimeTimezoneUTC,
     NativeLiterals,
+    OpenAlias,
     // pydocstyle
     BlankLineAfterLastSection(String),
     BlankLineAfterSection(String),
@@ -1215,6 +1217,7 @@ impl CheckCode {
             CheckCode::UP017 => CheckKind::DatetimeTimezoneUTC,
             CheckCode::UP018 => CheckKind::NativeLiterals,
             CheckCode::UP019 => CheckKind::TypingTextStrAlias,
+            CheckCode::UP020 => CheckKind::OpenAlias,
             // pydocstyle
             CheckCode::D100 => CheckKind::PublicModule,
             CheckCode::D101 => CheckKind::PublicClass,
@@ -1635,6 +1638,7 @@ impl CheckCode {
             CheckCode::UP017 => CheckCategory::Pyupgrade,
             CheckCode::UP018 => CheckCategory::Pyupgrade,
             CheckCode::UP019 => CheckCategory::Pyupgrade,
+            CheckCode::UP020 => CheckCategory::Pyupgrade,
             CheckCode::W292 => CheckCategory::Pycodestyle,
             CheckCode::W605 => CheckCategory::Pycodestyle,
             CheckCode::YTT101 => CheckCategory::Flake82020,
@@ -1848,6 +1852,7 @@ impl CheckKind {
             CheckKind::DatetimeTimezoneUTC => &CheckCode::UP017,
             CheckKind::NativeLiterals => &CheckCode::UP018,
             CheckKind::TypingTextStrAlias => &CheckCode::UP019,
+            CheckKind::OpenAlias => &CheckCode::UP020,
             // pydocstyle
             CheckKind::BlankLineAfterLastSection(..) => &CheckCode::D413,
             CheckKind::BlankLineAfterSection(..) => &CheckCode::D410,
@@ -2573,6 +2578,7 @@ impl CheckKind {
             CheckKind::RemoveSixCompat => "Unnecessary `six` compatibility usage".to_string(),
             CheckKind::DatetimeTimezoneUTC => "Use `datetime.UTC` alias".to_string(),
             CheckKind::NativeLiterals => "Unnecessary call to `str` and `bytes`".to_string(),
+            CheckKind::OpenAlias => "Use builtin `open` instead".to_string(),
             CheckKind::ConvertTypedDictFunctionalToClass(name) => {
                 format!("Convert `{name}` from `TypedDict` functional to class syntax")
             }
@@ -3015,6 +3021,7 @@ impl CheckKind {
                 | CheckKind::MisplacedComparisonConstant(..)
                 | CheckKind::MissingReturnTypeSpecialMethod(..)
                 | CheckKind::NativeLiterals
+                | CheckKind::OpenAlias
                 | CheckKind::NewLineAfterLastParagraph
                 | CheckKind::NewLineAfterSectionName(..)
                 | CheckKind::NoBlankLineAfterFunction(..)

src/checks_gen.rs

@@ -527,6 +527,8 @@ pub enum CheckCodePrefix {
     UP017,
     UP018,
     UP019,
+    UP02,
+    UP020,
     W,
     W2,
     W29,
@@ -2104,6 +2106,7 @@ impl CheckCodePrefix {
                     CheckCode::UP017,
                     CheckCode::UP018,
                     CheckCode::UP019,
+                    CheckCode::UP020,
                 ]
             }
             CheckCodePrefix::U0 => {
@@ -2132,6 +2135,7 @@ impl CheckCodePrefix {
                     CheckCode::UP017,
                     CheckCode::UP018,
                     CheckCode::UP019,
+                    CheckCode::UP020,
                 ]
             }
             CheckCodePrefix::U00 => {
@@ -2344,6 +2348,7 @@ impl CheckCodePrefix {
                 CheckCode::UP017,
                 CheckCode::UP018,
                 CheckCode::UP019,
+                CheckCode::UP020,
             ],
             CheckCodePrefix::UP0 => vec![
                 CheckCode::UP001,
@@ -2364,6 +2369,7 @@ impl CheckCodePrefix {
                 CheckCode::UP017,
                 CheckCode::UP018,
                 CheckCode::UP019,
+                CheckCode::UP020,
             ],
             CheckCodePrefix::UP00 => vec![
                 CheckCode::UP001,
@@ -2405,6 +2411,8 @@ impl CheckCodePrefix {
             CheckCodePrefix::UP017 => vec![CheckCode::UP017],
             CheckCodePrefix::UP018 => vec![CheckCode::UP018],
             CheckCodePrefix::UP019 => vec![CheckCode::UP019],
+            CheckCodePrefix::UP02 => vec![CheckCode::UP020],
+            CheckCodePrefix::UP020 => vec![CheckCode::UP020],
             CheckCodePrefix::W => vec![CheckCode::W292, CheckCode::W605],
             CheckCodePrefix::W2 => vec![CheckCode::W292],
             CheckCodePrefix::W29 => vec![CheckCode::W292],
@@ -2963,6 +2971,8 @@ impl CheckCodePrefix {
             CheckCodePrefix::UP017 => SuffixLength::Three,
             CheckCodePrefix::UP018 => SuffixLength::Three,
             CheckCodePrefix::UP019 => SuffixLength::Three,
+            CheckCodePrefix::UP02 => SuffixLength::Two,
+            CheckCodePrefix::UP020 => SuffixLength::Three,
             CheckCodePrefix::W => SuffixLength::Zero,
             CheckCodePrefix::W2 => SuffixLength::One,
             CheckCodePrefix::W29 => SuffixLength::Two,

src/pyupgrade/plugins/mod.rs

@@ -3,6 +3,7 @@ pub use convert_typed_dict_functional_to_class::convert_typed_dict_functional_to
 pub use datetime_utc_alias::datetime_utc_alias;
 pub use deprecated_unittest_alias::deprecated_unittest_alias;
 pub use native_literals::native_literals;
+pub use open_alias::open_alias;
 pub use redundant_open_modes::redundant_open_modes;
 pub use remove_six_compat::remove_six_compat;
 pub use super_call_with_parameters::super_call_with_parameters;
@@ -21,6 +22,7 @@ mod convert_typed_dict_functional_to_class;
 mod datetime_utc_alias;
 mod deprecated_unittest_alias;
 mod native_literals;
+mod open_alias;
 mod redundant_open_modes;
 mod remove_six_compat;
 mod super_call_with_parameters;

src/pyupgrade/plugins/open_alias.rs

@@ -0,0 +1,24 @@
+use rustpython_ast::Expr;
+
+use crate::ast::helpers::{collect_call_paths, dealias_call_path, match_call_path};
+use crate::ast::types::Range;
+use crate::autofix::Fix;
+use crate::checkers::ast::Checker;
+use crate::checks::{Check, CheckCode, CheckKind};
+
+/// UP020
+pub fn open_alias(checker: &mut Checker, expr: &Expr, func: &Expr) {
+    let call_path = dealias_call_path(collect_call_paths(expr), &checker.import_aliases);
+
+    if match_call_path(&call_path, "io", "open", &checker.from_imports) {
+        let mut check = Check::new(CheckKind::OpenAlias, Range::from_located(expr));
+        if checker.patch(&CheckCode::UP020) {
+            check.amend(Fix::replacement(
+                "open".to_string(),
+                func.location,
+                func.end_location.unwrap(),
+            ));
+        }
+        checker.add_check(check);
+    }
+}