[refurb] Mark fix as safe for readlines-in-for (FURB129)

crates/ruff_linter/resources/test/fixtures/refurb/FURB129.py

@@ -57,7 +57,7 @@ def func():
         pass
 
 
-# False positives
+# Ok
 def func(f):
     for _line in f.readlines():
         pass

crates/ruff_linter/src/preview.rs

@@ -116,3 +116,8 @@ pub(crate) const fn is_allow_nested_roots_enabled(settings: &LinterSettings) ->
 pub(crate) const fn is_check_file_level_directives_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/17644
+pub(crate) const fn is_readlines_in_for_fix_safe(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/refurb/mod.rs

@@ -61,6 +61,24 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(Rule::ReadlinesInFor, Path::new("FURB129.py"))]
+    fn preview(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!(
+            "preview__{}_{}",
+            rule_code.noqa_code(),
+            path.to_string_lossy()
+        );
+        let diagnostics = test_path(
+            Path::new("refurb").join(path).as_path(),
+            &settings::LinterSettings {
+                preview: settings::types::PreviewMode::Enabled,
+                ..settings::LinterSettings::for_rule(rule_code)
+            },
+        )?;
+        assert_messages!(snapshot, diagnostics);
+        Ok(())
+    }
+
     #[test]
     fn write_whole_file_python_39() -> Result<()> {
         let diagnostics = test_path(

crates/ruff_linter/src/rules/refurb/rules/readlines_in_for.rs

@@ -1,3 +1,4 @@
+use crate::preview::is_readlines_in_for_fix_safe;
 use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::{Comprehension, Expr, StmtFor};
@@ -85,8 +86,14 @@ fn readlines_in_iter(checker: &Checker, iter_expr: &Expr) {
     }
 
     let mut diagnostic = Diagnostic::new(ReadlinesInFor, expr_call.range());
-    diagnostic.set_fix(Fix::unsafe_edit(Edit::range_deletion(
-        expr_call.range().add_start(expr_attr.value.range().len()),
-    )));
+    diagnostic.set_fix(if is_readlines_in_for_fix_safe(checker.settings) {
+        Fix::safe_edit(Edit::range_deletion(
+            expr_call.range().add_start(expr_attr.value.range().len()),
+        ))
+    } else {
+        Fix::unsafe_edit(Edit::range_deletion(
+            expr_call.range().add_start(expr_attr.value.range().len()),
+        ))
+    });
     checker.report_diagnostic(diagnostic);
 }

crates/ruff_linter/src/rules/refurb/snapshots/ruff_linter__rules__refurb__tests__preview__FURB129_FURB129.py.snap

@@ -0,0 +1,243 @@
+---
+source: crates/ruff_linter/src/rules/refurb/mod.rs
+---
+FURB129.py:7:18: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+  |
+5 | # Errors
+6 | with open("FURB129.py") as f:
+7 |     for _line in f.readlines():
+  |                  ^^^^^^^^^^^^^ FURB129
+8 |         pass
+9 |     a = [line.lower() for line in f.readlines()]
+  |
+  = help: Remove `readlines()`
+
+ℹ Safe fix
+4 4 | 
+5 5 | # Errors
+6 6 | with open("FURB129.py") as f:
+7   |-    for _line in f.readlines():
+  7 |+    for _line in f:
+8 8 |         pass
+9 9 |     a = [line.lower() for line in f.readlines()]
+10 10 |     b = {line.upper() for line in f.readlines()}
+
+FURB129.py:9:35: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+ 7 |     for _line in f.readlines():
+ 8 |         pass
+ 9 |     a = [line.lower() for line in f.readlines()]
+   |                                   ^^^^^^^^^^^^^ FURB129
+10 |     b = {line.upper() for line in f.readlines()}
+11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+6  6  | with open("FURB129.py") as f:
+7  7  |     for _line in f.readlines():
+8  8  |         pass
+9     |-    a = [line.lower() for line in f.readlines()]
+   9  |+    a = [line.lower() for line in f]
+10 10 |     b = {line.upper() for line in f.readlines()}
+11 11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+12 12 | 
+
+FURB129.py:10:35: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+ 8 |         pass
+ 9 |     a = [line.lower() for line in f.readlines()]
+10 |     b = {line.upper() for line in f.readlines()}
+   |                                   ^^^^^^^^^^^^^ FURB129
+11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+7  7  |     for _line in f.readlines():
+8  8  |         pass
+9  9  |     a = [line.lower() for line in f.readlines()]
+10    |-    b = {line.upper() for line in f.readlines()}
+   10 |+    b = {line.upper() for line in f}
+11 11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+12 12 | 
+13 13 | with Path("FURB129.py").open() as f:
+
+FURB129.py:11:49: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+ 9 |     a = [line.lower() for line in f.readlines()]
+10 |     b = {line.upper() for line in f.readlines()}
+11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+   |                                                 ^^^^^^^^^^^^^ FURB129
+12 |
+13 | with Path("FURB129.py").open() as f:
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+8  8  |         pass
+9  9  |     a = [line.lower() for line in f.readlines()]
+10 10 |     b = {line.upper() for line in f.readlines()}
+11    |-    c = {line.lower(): line.upper() for line in f.readlines()}
+   11 |+    c = {line.lower(): line.upper() for line in f}
+12 12 | 
+13 13 | with Path("FURB129.py").open() as f:
+14 14 |     for _line in f.readlines():
+
+FURB129.py:14:18: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+13 | with Path("FURB129.py").open() as f:
+14 |     for _line in f.readlines():
+   |                  ^^^^^^^^^^^^^ FURB129
+15 |         pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+11 11 |     c = {line.lower(): line.upper() for line in f.readlines()}
+12 12 | 
+13 13 | with Path("FURB129.py").open() as f:
+14    |-    for _line in f.readlines():
+   14 |+    for _line in f:
+15 15 |         pass
+16 16 | 
+17 17 | for _line in open("FURB129.py").readlines():
+
+FURB129.py:17:14: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+15 |         pass
+16 |
+17 | for _line in open("FURB129.py").readlines():
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ FURB129
+18 |     pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+14 14 |     for _line in f.readlines():
+15 15 |         pass
+16 16 | 
+17    |-for _line in open("FURB129.py").readlines():
+   17 |+for _line in open("FURB129.py"):
+18 18 |     pass
+19 19 | 
+20 20 | for _line in Path("FURB129.py").open().readlines():
+
+FURB129.py:20:14: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+18 |     pass
+19 |
+20 | for _line in Path("FURB129.py").open().readlines():
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ FURB129
+21 |     pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+17 17 | for _line in open("FURB129.py").readlines():
+18 18 |     pass
+19 19 | 
+20    |-for _line in Path("FURB129.py").open().readlines():
+   20 |+for _line in Path("FURB129.py").open():
+21 21 |     pass
+22 22 | 
+23 23 | 
+
+FURB129.py:26:18: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+24 | def func():
+25 |     f = Path("FURB129.py").open()
+26 |     for _line in f.readlines():
+   |                  ^^^^^^^^^^^^^ FURB129
+27 |         pass
+28 |     f.close()
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+23 23 | 
+24 24 | def func():
+25 25 |     f = Path("FURB129.py").open()
+26    |-    for _line in f.readlines():
+   26 |+    for _line in f:
+27 27 |         pass
+28 28 |     f.close()
+29 29 | 
+
+FURB129.py:32:18: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+31 | def func(f: io.BytesIO):
+32 |     for _line in f.readlines():
+   |                  ^^^^^^^^^^^^^ FURB129
+33 |         pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+29 29 | 
+30 30 | 
+31 31 | def func(f: io.BytesIO):
+32    |-    for _line in f.readlines():
+   32 |+    for _line in f:
+33 33 |         pass
+34 34 | 
+35 35 | 
+
+FURB129.py:38:22: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+36 | def func():
+37 |     with (open("FURB129.py") as f, foo as bar):
+38 |         for _line in f.readlines():
+   |                      ^^^^^^^^^^^^^ FURB129
+39 |             pass
+40 |         for _line in bar.readlines():
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+35 35 | 
+36 36 | def func():
+37 37 |     with (open("FURB129.py") as f, foo as bar):
+38    |-        for _line in f.readlines():
+   38 |+        for _line in f:
+39 39 |             pass
+40 40 |         for _line in bar.readlines():
+41 41 |             pass
+
+FURB129.py:48:17: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+47 | with builtins.open("FURB129.py") as f:
+48 |     for line in f.readlines():
+   |                 ^^^^^^^^^^^^^ FURB129
+49 |         pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+45 45 | 
+46 46 | 
+47 47 | with builtins.open("FURB129.py") as f:
+48    |-    for line in f.readlines():
+   48 |+    for line in f:
+49 49 |         pass
+50 50 | 
+51 51 | 
+
+FURB129.py:56:17: FURB129 [*] Instead of calling `readlines()`, iterate over file object directly
+   |
+55 | with o("FURB129.py") as f:
+56 |     for line in f.readlines():
+   |                 ^^^^^^^^^^^^^ FURB129
+57 |         pass
+   |
+   = help: Remove `readlines()`
+
+ℹ Safe fix
+53 53 | 
+54 54 | 
+55 55 | with o("FURB129.py") as f:
+56    |-    for line in f.readlines():
+   56 |+    for line in f:
+57 57 |         pass
+58 58 | 
+59 59 |