Add autofix for W292 [NoNewLineAtEndOfFile] (#1354)

README.md

@@ -540,7 +540,7 @@ For more, see [pycodestyle](https://pypi.org/project/pycodestyle/2.9.1/) on PyPI
 | E743 | AmbiguousFunctionName | Ambiguous function name: `...` |  |
 | E902 | IOError | IOError: `...` |  |
 | E999 | SyntaxError | SyntaxError: `...` |  |
-| W292 | NoNewLineAtEndOfFile | No newline at end of file |  |
+| W292 | NoNewLineAtEndOfFile | No newline at end of file | 🛠 |
 | W605 | InvalidEscapeSequence | Invalid escape sequence: '\c' |  |
 
 ### mccabe (C90)

resources/test/fixtures/pycodestyle/W292_2.py

@@ -1,2 +1,2 @@
 def fn() -> None:
-    pass
+    print("Newline present (no W292)")

resources/test/fixtures/pycodestyle/W292_4.py

@@ -0,0 +1 @@
+ 

src/checkers/lines.rs

@@ -55,7 +55,11 @@ pub fn check_lines(
     }
 
     if enforce_no_newline_at_end_of_file {
-        if let Some(check) = no_newline_at_end_of_file(contents) {
+        if let Some(check) = no_newline_at_end_of_file(
+            contents,
+            matches!(autofix, flags::Autofix::Enabled)
+                && settings.fixable.contains(&CheckCode::W292),
+        ) {
             checks.push(check);
         }
     }

src/checks.rs

@@ -2983,6 +2983,7 @@ impl CheckKind {
                 | CheckKind::NoBlankLineBeforeClass(..)
                 | CheckKind::NoBlankLineBeforeFunction(..)
                 | CheckKind::NoBlankLinesBetweenHeaderAndContent(..)
+                | CheckKind::NoNewLineAtEndOfFile
                 | CheckKind::NoOverIndentation
                 | CheckKind::NoSurroundingWhitespace
                 | CheckKind::NoUnderIndentation

src/pycodestyle/checks.rs

@@ -5,6 +5,7 @@ use rustpython_ast::{Located, Location, Stmt, StmtKind};
 use rustpython_parser::ast::{Cmpop, Expr, ExprKind};
 
 use crate::ast::types::Range;
+use crate::autofix::Fix;
 use crate::checks::{Check, CheckKind};
 use crate::source_code_locator::SourceCodeLocator;
 
@@ -134,18 +135,24 @@ pub fn ambiguous_function_name(name: &str, location: Range) -> Option<Check> {
 }
 
 /// W292
-pub fn no_newline_at_end_of_file(contents: &str) -> Option<Check> {
+pub fn no_newline_at_end_of_file(contents: &str, autofix: bool) -> Option<Check> {
     if !contents.ends_with('\n') {
         // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't
         // want to raise W292 anyway).
         if let Some(line) = contents.lines().last() {
-            return Some(Check::new(
+            // Both locations are at the end of the file (and thus the same).
+            let location = Location::new(contents.lines().count(), line.len());
+            let mut check = Check::new(
                 CheckKind::NoNewLineAtEndOfFile,
                 Range {
-                    location: Location::new(contents.lines().count(), line.len() + 1),
-                    end_location: Location::new(contents.lines().count(), line.len() + 1),
+                    location,
+                    end_location: location,
                 },
-            ));
+            );
+            if autofix {
+                check.amend(Fix::insertion("\n".to_string(), location));
+            }
+            return Some(check);
         }
     }
     None

src/pycodestyle/mod.rs

@@ -31,6 +31,8 @@ mod tests {
     #[test_case(CheckCode::W292, Path::new("W292_0.py"))]
     #[test_case(CheckCode::W292, Path::new("W292_1.py"))]
     #[test_case(CheckCode::W292, Path::new("W292_2.py"))]
+    #[test_case(CheckCode::W292, Path::new("W292_3.py"))]
+    #[test_case(CheckCode::W292, Path::new("W292_4.py"))]
     #[test_case(CheckCode::W605, Path::new("W605_0.py"))]
     #[test_case(CheckCode::W605, Path::new("W605_1.py"))]
     fn checks(check_code: CheckCode, path: &Path) -> Result<()> {

src/pycodestyle/snapshots/ruff__pycodestyle__tests__W292_W292_0.py.snap

@@ -5,9 +5,16 @@ expression: checks
 - kind: NoNewLineAtEndOfFile
   location:
     row: 2
-    column: 9
+    column: 8
   end_location:
     row: 2
-    column: 9
-  fix: ~
+    column: 8
+  fix:
+    content: "\n"
+    location:
+      row: 2
+      column: 8
+    end_location:
+      row: 2
+      column: 8
 

src/pycodestyle/snapshots/ruff__pycodestyle__tests__W292_W292_3.py.snap

@@ -0,0 +1,6 @@
+---
+source: src/pycodestyle/mod.rs
+expression: checks
+---
+[]
+

src/pycodestyle/snapshots/ruff__pycodestyle__tests__W292_W292_4.py.snap

@@ -0,0 +1,20 @@
+---
+source: src/pycodestyle/mod.rs
+expression: checks
+---
+- kind: NoNewLineAtEndOfFile
+  location:
+    row: 1
+    column: 1
+  end_location:
+    row: 1
+    column: 1
+  fix:
+    content: "\n"
+    location:
+      row: 1
+      column: 1
+    end_location:
+      row: 1
+      column: 1
+