rfc6570-expand/lib/expression-parser.js

A template processor for RFC 6570 URI Template

"use strict";
const u = (s) => {
    return encodeURIComponent(s).replace(/[!'()*]/g, (c) => {
        return '%' + c.charCodeAt(0).toString(16);
    });
};
const ur = (s) => {
    return encodeURI(s).replace(/%5B/g, '[').replace(/%5D/g, ']');
};
const parseOperator = (expression) => {
    const defaultOperator = {
        key: null, first: '', sep: ',', named: false, ifemp: '', allow: u
    };
    const operators = [
        { key: '+', first: '', sep: ',', named: false, ifemp: '', allow: ur },
        { key: '.', first: '.', sep: '.', named: false, ifemp: '', allow: u },
        { key: '/', first: '/', sep: '/', named: false, ifemp: '', allow: u },
        { key: ';', first: ';', sep: ';', named: true, ifemp: '', allow: u },
        { key: '?', first: '?', sep: '&', named: true, ifemp: '=', allow: u },
        { key: '&', first: '&', sep: '&', named: true, ifemp: '=', allow: u },
        { key: '#', first: '#', sep: ',', named: false, ifemp: '', allow: ur }
    ];
    const operator = operators.find(o => o.key === expression.charAt(1));
    return operator ? operator : defaultOperator;
};
const compileVarSpecPattern = () => {
    const varChar = '(?:[A-Za-z0-9_]|%[A-Fa-f0-9][A-Fa-f0-9])';
    const varName = `(${varChar}(?:\\.?${varChar})*?)`;
    const prefix = ':([1-9][0-9]{0,3})';
    const explode = '(\\*)';
    const modifierLevel4 = `${prefix}|${explode}`;
    const varSpecPattern = new RegExp(`^${varName}(?:${modifierLevel4})?$`);
    return varSpecPattern;
};
const parseVarSpec = (p, s) => {
    const match = s.match(p);
    if (!match)
        throw new Error('invalid varspec');
    const varName = match[1];
    const maxLength = typeof match[2] === 'undefined'
        ? undefined : parseInt(match[2], 10);
    const explode = !!match[3];
    return { varName: varName, maxLength: maxLength, explode: explode };
};
const varSpecParser = () => {
    const p = compileVarSpecPattern();
    return (s) => parseVarSpec(p, s);
};
const expressionParser = () => {
    const parser = varSpecParser();
    return s => {
        const operator = parseOperator(s);
        const hasOperator = !!operator.key;
        const varSpecs = s
            .slice((hasOperator ? 2 : 1), s.length - 1)
            .split(',')
            .map(parser);
        return {
            operator: operator,
            varSpecs: varSpecs
        };
    };
};
exports.expressionParser = expressionParser;