[internal] ComparableExpr (f)strings and bytes made invariant under concatenation (#13301)

crates/ruff_python_ast_integration_tests/tests/comparable.rs

@@ -0,0 +1,47 @@
+use ruff_python_ast::comparable::ComparableExpr;
+use ruff_python_parser::{parse_expression, ParseError};
+
+#[test]
+fn concatenated_strings_compare_equal() -> Result<(), ParseError> {
+    let split_contents = r#"'a' 'b' r'\n raw'"#;
+    let value_contents = r#"'ab\\n raw'"#;
+
+    let split_parsed = parse_expression(split_contents)?;
+    let value_parsed = parse_expression(value_contents)?;
+
+    let split_compr = ComparableExpr::from(split_parsed.expr());
+    let value_compr = ComparableExpr::from(value_parsed.expr());
+
+    assert_eq!(split_compr, value_compr);
+    Ok(())
+}
+
+#[test]
+fn concatenated_bytes_compare_equal() -> Result<(), ParseError> {
+    let split_contents = r#"b'a' b'b'"#;
+    let value_contents = r#"b'ab'"#;
+
+    let split_parsed = parse_expression(split_contents)?;
+    let value_parsed = parse_expression(value_contents)?;
+
+    let split_compr = ComparableExpr::from(split_parsed.expr());
+    let value_compr = ComparableExpr::from(value_parsed.expr());
+
+    assert_eq!(split_compr, value_compr);
+    Ok(())
+}
+
+#[test]
+fn concatenated_fstrings_compare_equal() -> Result<(), ParseError> {
+    let split_contents = r#"f"{foo!r} this" r"\n raw" f" and {bar!s} that""#;
+    let value_contents = r#"f"{foo!r} this\\n raw and {bar!s} that""#;
+
+    let split_parsed = parse_expression(split_contents)?;
+    let value_parsed = parse_expression(value_contents)?;
+
+    let split_compr = ComparableExpr::from(split_parsed.expr());
+    let value_compr = ComparableExpr::from(value_parsed.expr());
+
+    assert_eq!(split_compr, value_compr);
+    Ok(())
+}