fentastic/dist/esm/parseEnPassantTargetSquare.js

Validate and parse Forsyth-Edwards Notation (FEN) used to describe a chess game board position.

import { ParseError } from './ParseError.js';
const rankPattern = /[a-h]/gi;
const enPassantFilePattern = /3|6/g;
const fieldName = 'En passant target square';
export const validateEnPassantTargetSquare = (field) => {
    try {
        if (!field.tokens.length) {
            throw new ParseError(fieldName, '', field.delimiter.index, '-|a-h');
        }
        if (field.value === '-') {
            return field;
        }
        if (field.tokens.length !== 2) {
            throw new ParseError(fieldName, field.tokens.length, field.tokens[0].index, '2', 'field length to be', 'count');
        }
        if (!field.tokens[0].value.match(rankPattern)) {
            throw new ParseError(fieldName, field.tokens[0].value, field.tokens[0].index, 'a-h');
        }
        if (!field.tokens[1].value.match(enPassantFilePattern)) {
            throw new ParseError(fieldName, field.tokens[1].value, field.tokens[1].index, '3|6');
        }
    }
    catch (e) {
        if (e instanceof ParseError) {
            field.error = e;
        }
        else {
            throw e;
        }
    }
    return field;
};
export const parseEnPassantTargetSquare = (field) => {
    if (field.value === '-') {
        return undefined;
    }
    return field.value;
};