node/tools/node_modules/eslint/lib/linter/interpolate.js

/**
 * @fileoverview Interpolate keys from an object into a string with {{ }} markers.
 * @author Jed Fox
 */

"use strict";

//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------

module.exports = (text, data) => {
    if (!data) {
        return text;
    }

    // Substitution content for any {{ }} markers.
    return text.replace(/\{\{([^{}]+?)\}\}/gu, (fullMatch, termWithWhitespace) => {
        const term = termWithWhitespace.trim();

        if (term in data) {
            return data[term];
        }

        // Preserve old behavior: If parameter name not provided, don't replace it.
        return fullMatch;
    });
};