biome_js_formatter 0.0.2

Biome's JavaScript formatter
Documentation 
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use crate::prelude::*;
use biome_formatter::write;

use crate::parentheses::NeedsParentheses;
use biome_js_syntax::JsRegexLiteralExpressionFields;
use biome_js_syntax::{JsRegexLiteralExpression, JsSyntaxNode};

#[derive(Debug, Clone, Default)]
pub(crate) struct FormatJsRegexLiteralExpression;

impl FormatNodeRule<JsRegexLiteralExpression> for FormatJsRegexLiteralExpression {
    fn fmt_fields(&self, node: &JsRegexLiteralExpression, f: &mut JsFormatter) -> FormatResult<()> {
        let JsRegexLiteralExpressionFields { value_token } = node.as_fields();
        let value_token = value_token?;
        let trimmed_raw_string = value_token.text_trimmed();
        // find end slash, so we could split our regex literal to two part `body`: raw_string[0..end_slash_pos + 1] and `flags`: raw_string[end_slash_pos + 1..]
        // reference https://tc39.es/ecma262/#prod-RegularExpressionLiteral
        let ends_with_slash = trimmed_raw_string.ends_with('/');
        // this means that we have a regex literal with no flags
        if ends_with_slash {
            return write!(f, [value_token.format()]);
        }

        // SAFETY: a valid regex literal must have a end slash
        let end_slash_pos = trimmed_raw_string.rfind('/').unwrap();
        let mut flag_char_vec = trimmed_raw_string[end_slash_pos + 1..]
            .chars()
            .collect::<Vec<_>>();
        flag_char_vec.sort_unstable();
        let sorted_flag_string = flag_char_vec.iter().collect::<String>();

        let sorted_regex_literal = syntax_token_cow_slice(
            std::borrow::Cow::Owned(std::format!(
                "{}{}",
                &trimmed_raw_string[0..end_slash_pos + 1],
                sorted_flag_string
            )),
            &value_token,
            value_token.text_trimmed_range().start(),
        );

        write!(f, [format_replaced(&value_token, &sorted_regex_literal)])
    }

    fn needs_parentheses(&self, item: &JsRegexLiteralExpression) -> bool {
        item.needs_parentheses()
    }
}

impl NeedsParentheses for JsRegexLiteralExpression {
    #[inline(always)]
    fn needs_parentheses(&self) -> bool {
        false
    }
    #[inline(always)]
    fn needs_parentheses_with_parent(&self, _parent: &JsSyntaxNode) -> bool {
        false
    }
}