@sqb/connect/esm/orm/util/parse-fields-projection.js

Multi-dialect database connection framework written with TypeScript

import { splitString } from 'fast-tokenizer';
const FIELD_PATTERN = /^([+-])?([a-z_$]\w*)$/i;
const NO_DOT_BRACKET_PATTERN = /[^.]\(/g;
export class FieldsProjection {
}
(function (FieldsProjection) {
    class Item {
    }
    FieldsProjection.Item = Item;
})(FieldsProjection || (FieldsProjection = {}));
export function parseFieldsProjection(projection, keepCase) {
    const arr = Array.isArray(projection) ? projection : [projection];
    if (!(arr && arr.length))
        return;
    const out = new FieldsProjection();
    for (let s of arr) {
        if (!keepCase)
            s = s.toLowerCase();
        parse(s, out);
    }
    return out;
}
function parse(input, target) {
    /** Add dot before brackets which is required to split fields */
    input = input.replace(NO_DOT_BRACKET_PATTERN, s => s.charAt(0) + '.' + s.substring(1));
    const fields = splitString(input, {
        delimiters: '.',
        brackets: true,
        keepBrackets: false,
    });
    for (let i = 0; i < fields.length; i++) {
        const f = fields[i];
        if (f.includes(',')) {
            const subFields = splitString(f, {
                delimiters: ',',
                brackets: true,
                keepBrackets: true,
            });
            for (const n of subFields) {
                parse(n, target);
            }
            continue;
        }
        const m = FIELD_PATTERN.exec(f);
        /* istanbul ignore next */
        if (!m)
            throw new TypeError(`Invalid field path (${input})`);
        const fieldName = m[2];
        const treeItem = (target[fieldName] =
            target[fieldName] || new FieldsProjection.Item());
        if (m[1])
            treeItem.sign = m[1];
        if (i === fields.length - 1) {
            delete treeItem.projection;
        }
        else {
            target = treeItem.projection =
                treeItem.projection || new FieldsProjection();
        }
    }
}