Write autofixer for ISC001 (astral-sh#4829)

crates/ruff/resources/test/fixtures/flake8_implicit_str_concat/ISC.py

@@ -34,3 +34,13 @@
   b"abc"
   b"def"
 )
+
+_ = """a""" """b"""
+
+_ = f"""a""" f"""b"""
+
+_ = f"a" "b"
+
+_ = """a""" "b"
+
+_ = 'a' "b"

crates/ruff/src/rules/flake8_implicit_str_concat/rules/implicit.rs

@@ -1,9 +1,9 @@
 use itertools::Itertools;
 use ruff_text_size::TextRange;
-use rustpython_parser::lexer::LexResult;
 use rustpython_parser::Tok;
+use rustpython_parser::{lexer::LexResult, StringKind};
 
-use ruff_diagnostics::{Diagnostic, Violation};
+use ruff_diagnostics::{AutofixKind, Diagnostic, Edit, Fix, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::source_code::Locator;
 
@@ -34,10 +34,16 @@ use crate::rules::flake8_implicit_str_concat::settings::Settings;
 pub struct SingleLineImplicitStringConcatenation;
 
 impl Violation for SingleLineImplicitStringConcatenation {
+    const AUTOFIX: AutofixKind = AutofixKind::Sometimes;
+
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Implicitly concatenated string literals on one line")
     }
+
+    fn autofix_title(&self) -> Option<String> {
+        Option::Some("Combine these string literals into one".to_string())
+    }
 }
 
 /// ## What it does
@@ -99,19 +105,115 @@ pub(crate) fn implicit(
         })
         .tuple_windows()
     {
-        if matches!(a_tok, Tok::String { .. }) && matches!(b_tok, Tok::String { .. }) {
+        if let (
+            Tok::String {
+                kind: _a_kind,
+                triple_quoted: _a_triple_quoted,
+                value: _a_value,
+                ..
+            },
+            Tok::String {
+                kind: _b_kind,
+                triple_quoted: _b_triple_quoted,
+                value: _b_value,
+                ..
+            },
+        ) = (a_tok, b_tok)
+        {
             if locator.contains_line_break(TextRange::new(a_range.end(), b_range.start())) {
                 diagnostics.push(Diagnostic::new(
                     MultiLineImplicitStringConcatenation,
                     TextRange::new(a_range.start(), b_range.end()),
                 ));
             } else {
-                diagnostics.push(Diagnostic::new(
-                    SingleLineImplicitStringConcatenation,
-                    TextRange::new(a_range.start(), b_range.end()),
-                ));
-            }
-        }
+                let range = TextRange::new(a_range.start(), b_range.end());
+
+                let mut diagnostic = Diagnostic::new(SingleLineImplicitStringConcatenation, range);
+
+                if let Some(fix) = get_fix_for_single_line_implicit_string_concatenation(
+                    &a_tok, *a_range, &b_tok, *b_range, locator,
+                ) {
+                    diagnostic.set_fix(fix);
+                }
+
+                diagnostics.push(diagnostic);
+            };
+        };
     }
     diagnostics
 }
+
+fn get_fix_for_single_line_implicit_string_concatenation(
+    a_tok: &Tok,
+    a_range: TextRange,
+    b_tok: &Tok,
+    b_range: TextRange,
+    locator: &Locator,
+) -> Option<Fix> {
+    let (
+        Tok::String {
+            kind: a_kind,
+            triple_quoted: a_triple_quoted,
+            ..
+        },
+        Tok::String {
+            kind: b_kind,
+            triple_quoted: b_triple_quoted,
+            ..
+        },
+    ) = (a_tok, b_tok) else { return Option::None };
+
+    // Fix only strings of the same kind and triple-quotedness
+    if a_kind != b_kind || a_triple_quoted != b_triple_quoted {
+        return Option::None;
+    }
+
+    let a_text = &locator.contents()[a_range];
+    let b_text = &locator.contents()[b_range];
+
+    let a_quotes_style = get_quotes_style(a_text);
+    let b_quotes_style = get_quotes_style(b_text);
+
+    // Fix only strings with the same quotes style
+    if a_quotes_style != b_quotes_style {
+        return Option::None;
+    }
+
+    let text = skip_string_end(*a_triple_quoted, a_text).to_string()
+        + skip_string_start(*b_kind, *b_triple_quoted, b_text);
+
+    Option::Some(Fix::automatic(Edit::range_replacement(
+        text,
+        TextRange::new(a_range.start(), b_range.end()),
+    )))
+}
+
+fn skip_string_start(kind: StringKind, triple_quoted: bool, text: &str) -> &str {
+    let quotes_len = match kind {
+        StringKind::String => 0,
+        StringKind::Bytes | StringKind::FString | StringKind::Unicode | StringKind::RawString => 1,
+        StringKind::RawBytes | StringKind::RawFString => 2,
+    } + (if triple_quoted { 3 } else { 1 });
+
+    &text[quotes_len..]
+}
+
+fn skip_string_end(triple_quoted: bool, text: &str) -> &str {
+    let quotes_len = if triple_quoted { 3 } else { 1 };
+
+    &text[..text.len() - quotes_len]
+}
+
+#[derive(PartialEq)]
+enum QuotesStyle {
+    Double,
+    Single,
+}
+
+fn get_quotes_style(text: &str) -> QuotesStyle {
+    if text.ends_with('\"') {
+        QuotesStyle::Double
+    } else {
+        QuotesStyle::Single
+    }
+}

crates/ruff/src/rules/flake8_implicit_str_concat/snapshots/ruff__rules__flake8_implicit_str_concat__tests__ISC001_ISC.py.snap

@@ -1,20 +1,109 @@
 ---
 source: crates/ruff/src/rules/flake8_implicit_str_concat/mod.rs
 ---
-ISC.py:1:5: ISC001 Implicitly concatenated string literals on one line
+ISC.py:1:5: ISC001 [*] Implicitly concatenated string literals on one line
   |
 1 | _ = "a" "b" "c"
   |     ^^^^^^^ ISC001
 2 | 
 3 | _ = "abc" + "def"
   |
+  = help: Combine these string literals into one
 
-ISC.py:1:9: ISC001 Implicitly concatenated string literals on one line
+ℹ Fix
+1   |-_ = "a" "b" "c"
+  1 |+_ = "ab" "c"
+2 2 | 
+3 3 | _ = "abc" + "def"
+4 4 | 
+
+ISC.py:1:9: ISC001 [*] Implicitly concatenated string literals on one line
   |
 1 | _ = "a" "b" "c"
   |         ^^^^^^^ ISC001
 2 | 
 3 | _ = "abc" + "def"
   |
+  = help: Combine these string literals into one
+
+ℹ Fix
+1   |-_ = "a" "b" "c"
+  1 |+_ = "a" "bc"
+2 2 | 
+3 3 | _ = "abc" + "def"
+4 4 | 
+
+ISC.py:38:5: ISC001 [*] Implicitly concatenated string literals on one line
+   |
+38 | )
+39 | 
+40 | _ = """a""" """b"""
+   |     ^^^^^^^^^^^^^^^ ISC001
+41 | 
+42 | _ = f"""a""" f"""b"""
+   |
+   = help: Combine these string literals into one
+
+ℹ Fix
+35 35 |   b"def"
+36 36 | )
+37 37 | 
+38    |-_ = """a""" """b"""
+   38 |+_ = """ab"""
+39 39 | 
+40 40 | _ = f"""a""" f"""b"""
+41 41 | 
+
+ISC.py:40:5: ISC001 [*] Implicitly concatenated string literals on one line
+   |
+40 | _ = """a""" """b"""
+41 | 
+42 | _ = f"""a""" f"""b"""
+   |     ^^^^^^^^^^^^^^^^^ ISC001
+43 | 
+44 | _ = f"a" "b"
+   |
+   = help: Combine these string literals into one
+
+ℹ Fix
+37 37 | 
+38 38 | _ = """a""" """b"""
+39 39 | 
+40    |-_ = f"""a""" f"""b"""
+   40 |+_ = f"""ab"""
+41 41 | 
+42 42 | _ = f"a" "b"
+43 43 | 
+
+ISC.py:42:5: ISC001 Implicitly concatenated string literals on one line
+   |
+42 | _ = f"""a""" f"""b"""
+43 | 
+44 | _ = f"a" "b"
+   |     ^^^^^^^^ ISC001
+45 | 
+46 | _ = """a""" "b"
+   |
+   = help: Combine these string literals into one
+
+ISC.py:44:5: ISC001 Implicitly concatenated string literals on one line
+   |
+44 | _ = f"a" "b"
+45 | 
+46 | _ = """a""" "b"
+   |     ^^^^^^^^^^^ ISC001
+47 | 
+48 | _ = 'a' "b"
+   |
+   = help: Combine these string literals into one
+
+ISC.py:46:5: ISC001 Implicitly concatenated string literals on one line
+   |
+46 | _ = """a""" "b"
+47 | 
+48 | _ = 'a' "b"
+   |     ^^^^^^^ ISC001
+   |
+   = help: Combine these string literals into one
 
 

crates/ruff/src/rules/flake8_implicit_str_concat/snapshots/ruff__rules__flake8_implicit_str_concat__tests__multiline_ISC001_ISC.py.snap

@@ -1,20 +1,109 @@
 ---
 source: crates/ruff/src/rules/flake8_implicit_str_concat/mod.rs
 ---
-ISC.py:1:5: ISC001 Implicitly concatenated string literals on one line
+ISC.py:1:5: ISC001 [*] Implicitly concatenated string literals on one line
   |
 1 | _ = "a" "b" "c"
   |     ^^^^^^^ ISC001
 2 | 
 3 | _ = "abc" + "def"
   |
+  = help: Combine these string literals into one
 
-ISC.py:1:9: ISC001 Implicitly concatenated string literals on one line
+ℹ Fix
+1   |-_ = "a" "b" "c"
+  1 |+_ = "ab" "c"
+2 2 | 
+3 3 | _ = "abc" + "def"
+4 4 | 
+
+ISC.py:1:9: ISC001 [*] Implicitly concatenated string literals on one line
   |
 1 | _ = "a" "b" "c"
   |         ^^^^^^^ ISC001
 2 | 
 3 | _ = "abc" + "def"
   |
+  = help: Combine these string literals into one
+
+ℹ Fix
+1   |-_ = "a" "b" "c"
+  1 |+_ = "a" "bc"
+2 2 | 
+3 3 | _ = "abc" + "def"
+4 4 | 
+
+ISC.py:38:5: ISC001 [*] Implicitly concatenated string literals on one line
+   |
+38 | )
+39 | 
+40 | _ = """a""" """b"""
+   |     ^^^^^^^^^^^^^^^ ISC001
+41 | 
+42 | _ = f"""a""" f"""b"""
+   |
+   = help: Combine these string literals into one
+
+ℹ Fix
+35 35 |   b"def"
+36 36 | )
+37 37 | 
+38    |-_ = """a""" """b"""
+   38 |+_ = """ab"""
+39 39 | 
+40 40 | _ = f"""a""" f"""b"""
+41 41 | 
+
+ISC.py:40:5: ISC001 [*] Implicitly concatenated string literals on one line
+   |
+40 | _ = """a""" """b"""
+41 | 
+42 | _ = f"""a""" f"""b"""
+   |     ^^^^^^^^^^^^^^^^^ ISC001
+43 | 
+44 | _ = f"a" "b"
+   |
+   = help: Combine these string literals into one
+
+ℹ Fix
+37 37 | 
+38 38 | _ = """a""" """b"""
+39 39 | 
+40    |-_ = f"""a""" f"""b"""
+   40 |+_ = f"""ab"""
+41 41 | 
+42 42 | _ = f"a" "b"
+43 43 | 
+
+ISC.py:42:5: ISC001 Implicitly concatenated string literals on one line
+   |
+42 | _ = f"""a""" f"""b"""
+43 | 
+44 | _ = f"a" "b"
+   |     ^^^^^^^^ ISC001
+45 | 
+46 | _ = """a""" "b"
+   |
+   = help: Combine these string literals into one
+
+ISC.py:44:5: ISC001 Implicitly concatenated string literals on one line
+   |
+44 | _ = f"a" "b"
+45 | 
+46 | _ = """a""" "b"
+   |     ^^^^^^^^^^^ ISC001
+47 | 
+48 | _ = 'a' "b"
+   |
+   = help: Combine these string literals into one
+
+ISC.py:46:5: ISC001 Implicitly concatenated string literals on one line
+   |
+46 | _ = """a""" "b"
+47 | 
+48 | _ = 'a' "b"
+   |     ^^^^^^^ ISC001
+   |
+   = help: Combine these string literals into one