asciidisco.com/build/node_modules/sw-precache/service-worker.tmpl

/**
 * Copyright 2016 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/

// DO NOT EDIT THIS GENERATED OUTPUT DIRECTLY!
// This file should be overwritten as part of your build process.
// If you need to extend the behavior of the generated service worker, the best approach is to write
// additional code and include it using the importScripts option:
//   https://github.com/GoogleChrome/sw-precache#importscripts-arraystring
//
// Alternatively, it's possible to make changes to the underlying template file and then use that as the
// new base for generating output, via the templateFilePath option:
//   https://github.com/GoogleChrome/sw-precache#templatefilepath-string
//
// If you go that route, make sure that whenever you update your sw-precache dependency, you reconcile any
// changes made to this original template file with your modified copy.

// This generated service worker JavaScript will precache your site's resources.
// The code needs to be saved in a .js file at the top-level of your site, and registered
// from your pages in order to be used. See
// https://github.com/googlechrome/sw-precache/blob/master/demo/app/js/service-worker-registration.js
// for an example of how you can register this script and handle various service worker events.

/* eslint-env worker, serviceworker */
/* eslint-disable indent, no-unused-vars, no-multiple-empty-lines, max-nested-callbacks, space-before-function-paren, quotes, comma-spacing */
'use strict';

var precacheConfig = <%= precacheConfig %>;
var cacheName = 'sw-precache-<%= version %>-<%= cacheId %>-' + (self.registration ? self.registration.scope : '');

<% if (handleFetch) { %>
var ignoreUrlParametersMatching = [<%= ignoreUrlParametersMatching %>];
<% } %>

<% Object.keys(externalFunctions).sort().forEach(function(functionName) {%>
var <%- functionName %> = <%= externalFunctions[functionName] %>;
<% }); %>

var hashParamName = '_sw-precache';
var urlsToCacheKeys = new Map(
  precacheConfig.map(function(item) {
    var relativeUrl = item[0];
    var hash = item[1];
    var absoluteUrl = new URL(relativeUrl, self.location);
    var cacheKey = createCacheKey(absoluteUrl, hashParamName, hash, <%= dontCacheBustUrlsMatching %>);
    return [absoluteUrl.toString(), cacheKey];
  })
);

function setOfCachedUrls(cache) {
  return cache.keys().then(function(requests) {
    return requests.map(function(request) {
      return request.url;
    });
  }).then(function(urls) {
    return new Set(urls);
  });
}

self.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open(cacheName).then(function(cache) {
      return setOfCachedUrls(cache).then(function(cachedUrls) {
        return Promise.all(
          Array.from(urlsToCacheKeys.values()).map(function(cacheKey) {
            // If we don't have a key matching url in the cache already, add it.
            if (!cachedUrls.has(cacheKey)) {
              var request = new Request(cacheKey, {credentials: 'same-origin'});
              return fetch(request).then(function(response) {
                // Bail out of installation unless we get back a 200 OK for
                // every request.
                if (!response.ok) {
                  throw new Error('Request for ' + cacheKey + ' returned a ' +
                    'response with status ' + response.status);
                }

                return cleanResponse(response).then(function(responseToCache) {
                  return cache.put(cacheKey, responseToCache);
                });
              });
            }
          })
        );
      });
    }).then(function() {
      <% if (skipWaiting) { %>
      // Force the SW to transition from installing -> active state
      return self.skipWaiting();
      <% } %>
    })
  );
});

self.addEventListener('activate', function(event) {
  var setOfExpectedUrls = new Set(urlsToCacheKeys.values());

  event.waitUntil(
    caches.open(cacheName).then(function(cache) {
      return cache.keys().then(function(existingRequests) {
        return Promise.all(
          existingRequests.map(function(existingRequest) {
            if (!setOfExpectedUrls.has(existingRequest.url)) {
              return cache.delete(existingRequest);
            }
          })
        );
      });
    }).then(function() {
      <% if (clientsClaim) { %>
      return self.clients.claim();
      <% } %>
    })
  );
});

<% if (handleFetch) { %>
self.addEventListener('fetch', function(event) {
  if (event.request.method === 'GET') {
    // Should we call event.respondWith() inside this fetch event handler?
    // This needs to be determined synchronously, which will give other fetch
    // handlers a chance to handle the request if need be.
    var shouldRespond;

    // First, remove all the ignored parameters and hash fragment, and see if we
    // have that URL in our cache. If so, great! shouldRespond will be true.
    var url = stripIgnoredUrlParameters(event.request.url, ignoreUrlParametersMatching);
    shouldRespond = urlsToCacheKeys.has(url);

    // If shouldRespond is false, check again, this time with 'index.html'
    // (or whatever the directoryIndex option is set to) at the end.
    var directoryIndex = '<%= directoryIndex %>';
    if (!shouldRespond && directoryIndex) {
      url = addDirectoryIndex(url, directoryIndex);
      shouldRespond = urlsToCacheKeys.has(url);
    }

    // If shouldRespond is still false, check to see if this is a navigation
    // request, and if so, whether the URL matches navigateFallbackWhitelist.
    var navigateFallback = '<%= navigateFallback %>';
    if (!shouldRespond &&
        navigateFallback &&
        (event.request.mode === 'navigate') &&
        isPathWhitelisted(<%= navigateFallbackWhitelist %>, event.request.url)) {
      url = new URL(navigateFallback, self.location).toString();
      shouldRespond = urlsToCacheKeys.has(url);
    }

    // If shouldRespond was set to true at any point, then call
    // event.respondWith(), using the appropriate cache key.
    if (shouldRespond) {
      event.respondWith(
        caches.open(cacheName).then(function(cache) {
          return cache.match(urlsToCacheKeys.get(url)).then(function(response) {
            if (response) {
              return response;
            }
            throw Error('The cached response that was expected is missing.');
          });
        }).catch(function(e) {
          // Fall back to just fetch()ing the request if some unexpected error
          // prevented the cached response from being valid.
          console.warn('Couldn\'t serve response for "%s" from cache: %O', event.request.url, e);
          return fetch(event.request);
        })
      );
    }
  }
});

<% if (swToolboxCode) { %>
// *** Start of auto-included sw-toolbox code. ***
<%= swToolboxCode %>
// *** End of auto-included sw-toolbox code. ***
<% } %>

<% if (runtimeCaching) { %>
// Runtime cache configuration, using the sw-toolbox library.
<%= runtimeCaching %>
<% } %>
<% } %>

<% if (importScripts) { %>
importScripts(<%= importScripts %>);
<% } %>