@web/dev-server-legacy/dist/isLegacyBrowser.js

Plugin for legacy browsers in @web/dev-server

"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    var desc = Object.getOwnPropertyDescriptor(m, k);
    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
      desc = { enumerable: true, get: function() { return m[k]; } };
    }
    Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
    Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
    o["default"] = v;
});
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
    __setModuleDefault(result, mod);
    return result;
};
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.isLegacyBrowser = void 0;
/* eslint-disable no-console */
const browserslist_useragent_1 = require("browserslist-useragent");
const browserslist_1 = __importDefault(require("browserslist"));
const caniuse = __importStar(require("caniuse-api"));
/**
 * We compile to es modules when the browser supports module scripts, dynamic imports
 * and import.meta.url. Unfortunately, caniuse doesn't report import.meta.url. Chrome 63
 * is the only browser which suppors dynamic imports but not import.meta.url.
 */
const moduleFeatures = ['es6-module', 'es6-module-dynamic-import'];
const cache = new Map();
const browserAliases = {
    'UC Browser': 'UCAndroid',
};
/**
 * The user agent parser does not always return a valid version for samsung,
 * so we need to normalize it.
 */
function normalizeSamsungVersion(browser, version) {
    try {
        (0, browserslist_1.default)(`${browser} ${version}`);
        // browserslist didn't throw, return the valid version
        return version;
    }
    catch (error) {
        // we gave an invalid version to browserslist, so we try to
        // find the nearest matching major version for samsung browser
        const validVersions = [
            ...Object.keys(browserslist_1.default.versionAliases.samsung),
            ...browserslist_1.default.data.samsung.versions,
        ];
        return validVersions.find(validVersion => validVersion[0] === version[0]);
    }
}
/**
 * The user agent parser returns patch versions, which browserslist doesn't
 * know about. Mostly the major version is sufficient, except for safari.
 */
function getBrowserVersion(resolvedUA) {
    const version = resolvedUA.version.split('.');
    switch (resolvedUA.family) {
        case 'Safari':
        case 'iOS':
            return `${version[0]}.${version[1]}`;
        case 'Samsung':
            return normalizeSamsungVersion(resolvedUA.family, version);
        default:
            return version[0];
    }
}
function getBrowserName(browserName) {
    return browserAliases[browserName] || browserName;
}
/**
 * Returns whether this browser supports es modules. We count this when the browser
 * supports module syntax, scripts, dynamic imports. We can't feature detect
 * import.meta.url but any browsers which supports dynamic import supports import.meta.url,
 * except for chrome 63.
 */
function getSupportsEsm(browserTarget) {
    if (browserTarget.toLowerCase() === 'chrome 63') {
        return false;
    }
    return moduleFeatures.every(ft => caniuse.isSupported(ft, browserTarget));
}
/**
 * Calculates the user agent's compatibility.
 */
function calculateIsLegacyBrowser(userAgent, logger) {
    try {
        const resolvedUA = (0, browserslist_useragent_1.resolveUserAgent)(userAgent);
        const browserTarget = `${getBrowserName(resolvedUA.family)} ${getBrowserVersion(resolvedUA)}`;
        return !getSupportsEsm(browserTarget);
    }
    catch (error) {
        logger.warn(`[@web/dev-server-legacy]: Unknown user agent ${userAgent}, treating it as a legacy browser.`);
        return true;
    }
}
function isLegacyBrowser(ctx, logger) {
    const userAgent = ctx.get('user-agent');
    let isLegacyBrowser = cache.get(userAgent);
    if (isLegacyBrowser == null) {
        isLegacyBrowser = calculateIsLegacyBrowser(userAgent, logger);
        cache.set(userAgent, isLegacyBrowser);
    }
    return isLegacyBrowser;
}
exports.isLegacyBrowser = isLegacyBrowser;
//# sourceMappingURL=isLegacyBrowser.js.map