Ignore explicit-string-concatenation on single line (#6028)

## Summary

Ignore `explicit-string-concatenation` on single line.

Closes #5332.

## Test Plan

`cargo test`

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

@@ -50,3 +50,12 @@ _ = """a""" "b"
 _ = 'a' "b"
 
 _ = rf"a" rf"b"
+
+# Single-line explicit concatenation should be ignored.
+_ = "abc" + "def" + "ghi"
+_ = foo + "abc" + "def"
+_ = "abc" + foo + "def"
+_ = "abc" + "def" + foo
+_ = foo + bar + "abc"
+_ = "abc" + foo + bar
+_ = foo + "abc" + bar

crates/ruff/src/checkers/ast/analyze/expression.rs

@@ -1056,7 +1056,9 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
             op: Operator::Add, ..
         }) => {
             if checker.enabled(Rule::ExplicitStringConcatenation) {
-                if let Some(diagnostic) = flake8_implicit_str_concat::rules::explicit(expr) {
+                if let Some(diagnostic) =
+                    flake8_implicit_str_concat::rules::explicit(expr, checker.locator)
+                {
                     checker.diagnostics.push(diagnostic);
                 }
             }

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

@@ -2,6 +2,7 @@ use rustpython_parser::ast::{self, Constant, Expr, Operator, Ranged};
 
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::source_code::Locator;
 
 /// ## What it does
 /// Checks for string literals that are explicitly concatenated (using the
@@ -38,12 +39,12 @@ impl Violation for ExplicitStringConcatenation {
 }
 
 /// ISC003
-pub(crate) fn explicit(expr: &Expr) -> Option<Diagnostic> {
+pub(crate) fn explicit(expr: &Expr, locator: &Locator) -> Option<Diagnostic> {
     if let Expr::BinOp(ast::ExprBinOp {
         left,
         op,
         right,
-        range: _,
+        range,
     }) = expr
     {
         if matches!(op, Operator::Add) {
@@ -61,7 +62,8 @@ pub(crate) fn explicit(expr: &Expr) -> Option<Diagnostic> {
                         value: Constant::Str(..) | Constant::Bytes(..),
                         ..
                     })
-            ) {
+            ) && locator.contains_line_break(*range)
+            {
                 return Some(Diagnostic::new(ExplicitStringConcatenation, expr.range()));
             }
         }

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

@@ -138,6 +138,8 @@ ISC.py:52:5: ISC001 [*] Implicitly concatenated string literals on one line
 51 | 
 52 | _ = rf"a" rf"b"
    |     ^^^^^^^^^^^ ISC001
+53 | 
+54 | # Single-line explicit concatenation should be ignored.
    |
    = help: Combine string literals
 
@@ -147,5 +149,8 @@ ISC.py:52:5: ISC001 [*] Implicitly concatenated string literals on one line
 51 51 | 
 52    |-_ = rf"a" rf"b"
    52 |+_ = rf"ab"
+53 53 | 
+54 54 | # Single-line explicit concatenation should be ignored.
+55 55 | _ = "abc" + "def" + "ghi"
 
 

crates/ruff/src/rules/flake8_implicit_str_concat/snapshots/ruff__rules__flake8_implicit_str_concat__tests__ISC003_ISC.py.snap

@@ -1,16 +1,6 @@
 ---
 source: crates/ruff/src/rules/flake8_implicit_str_concat/mod.rs
 ---
-ISC.py:3:5: ISC003 Explicitly concatenated string should be implicitly concatenated
-  |
-1 | _ = "a" "b" "c"
-2 | 
-3 | _ = "abc" + "def"
-  |     ^^^^^^^^^^^^^ ISC003
-4 | 
-5 | _ = "abc" \
-  |
-
 ISC.py:9:3: ISC003 Explicitly concatenated string should be implicitly concatenated
    |
  8 |   _ = (

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

@@ -138,6 +138,8 @@ ISC.py:52:5: ISC001 [*] Implicitly concatenated string literals on one line
 51 | 
 52 | _ = rf"a" rf"b"
    |     ^^^^^^^^^^^ ISC001
+53 | 
+54 | # Single-line explicit concatenation should be ignored.
    |
    = help: Combine string literals
 
@@ -147,5 +149,8 @@ ISC.py:52:5: ISC001 [*] Implicitly concatenated string literals on one line
 51 51 | 
 52    |-_ = rf"a" rf"b"
    52 |+_ = rf"ab"
+53 53 | 
+54 54 | # Single-line explicit concatenation should be ignored.
+55 55 | _ = "abc" + "def" + "ghi"
 
 

crates/ruff/src/rules/flake8_implicit_str_concat/snapshots/ruff__rules__flake8_implicit_str_concat__tests__multiline_ISC003_ISC.py.snap

@@ -1,16 +1,6 @@
 ---
 source: crates/ruff/src/rules/flake8_implicit_str_concat/mod.rs
 ---
-ISC.py:3:5: ISC003 Explicitly concatenated string should be implicitly concatenated
-  |
-1 | _ = "a" "b" "c"
-2 | 
-3 | _ = "abc" + "def"
-  |     ^^^^^^^^^^^^^ ISC003
-4 | 
-5 | _ = "abc" \
-  |
-
 ISC.py:9:3: ISC003 Explicitly concatenated string should be implicitly concatenated
    |
  8 |   _ = (