Node script for creating a 'bower-lock.json' with exact versions

lockBower.js

const fs = require('fs');
const path = require('path');
const resolve = (...args) => path.join(__dirname, ...args);

const lockedVersions = getPackageVersions(resolve('bower_components'));
const newBowerContents = buildNewBowerContents(lockedVersions);

console.log(`Writing to bower-lock.json`);
fs.writeFileSync(resolve('./bower-lock.json'), newBowerContents, 'utf8');

/**
 * Reads the current bower.json and replaces every semver with the version from the actual package
 * @param {object} lockedVersions The locked versions
 * @return {object} The new bower contents.
 */
function buildNewBowerContents(lockedVersions) {
    const bowerFileContents = getBowerInfo(resolve('.'));

    const areas = ['dependencies', 'devDependencies'];

    areas.forEach(area => {
        if(!bowerFileContents[area]) {
            return;
        }
        const versionsToChange = {};

        console.log();
        console.log(`* Locked ${area}:`)

        Object.entries(bowerFileContents[area]).forEach(([name, version]) => {
            if(isNotDefinite(version) && lockedVersions[name] && lockedVersions[name] != version) {
                console.log(`${name}: ${version} -> ${lockedVersions[name]}`)
                versionsToChange[name] = lockedVersions[name];
            }
        });

        bowerFileContents[area] = { ...bowerFileContents[area], ...versionsToChange }
    })

    console.log();
    return JSON.stringify(bowerFileContents, null, 2);
}

/**
 * Reads the packages in the bower directory and returns an object with the package versions
 * @return {Object} The package versions.
 */
function getPackageVersions(bowerComponents) {
    try {
        const lockedVersions = fs.readdirSync(bowerComponents).reduce((acc, bowerPackage) => {
            const { version } = getBowerInfo(path.join(bowerComponents, bowerPackage));
            if(version) {
                acc[bowerPackage] = version;
            }
            return acc;
        }, {});
        return lockedVersions;
    } catch (e) {
        console.log(e);
        return {};
    }
}

/**
 * Reads and merges bower files in a directory
 * @param {string} dir The path to the directory
 * @return {object} the merged result of 'bower.json' and '.bower.json'
 */
function getBowerInfo(dir) {
    const names = ['bower.json', '.bower.json'];
    return names.reduce((acc, name) => {
        const fileName = path.join(dir, name);
        if(fs.existsSync(fileName)) {
            let content;
            try {
                content = JSON.parse(fs.readFileSync(fileName));
            } catch (e) {
                console.log(e);
                content = {};
            }
            return {...acc, ...content};
        } else {
            return acc;
        }
    }, {});             
}

/**
 * Determines if the version is not definite (~, ^, *).
 * @param {string} version The version
 * @return {boolean} True if not definite, False otherwise.
 */
function isNotDefinite(version) {
    return version && ['*', '~', '^'].indexOf(version[0]) !== -1; 
}

Usage

After installing bower packages and verifying everything works, go to the main folder (where bower_components is) and run:

node lockBower.js

It will go through the bower components and copy the exact versions.
A bower-lock.json file will be created, where the semver versions are replaced with the exact ones.
You can replace the original bower.json with it.