Include imported scripts to byte-check

This changes the behavior of the service worker script resource
comparison. Before this, only the main service worker script was
compared to a new version. With this change, all the imported scripts
stored in the imported scripts map as well as the main script are
inspected against the corresponding network resources (based on the
urls.)

Note:
 - Service worker's script resource map has been renamed and moved to
 service worker's script resource's imported scritps map.
 - registration's last update check time's always updated whenever the
 response is fetched from the network (regardless it's a main script or
 an imported script.)

Fixes #839.

docs/index.bs

@@ -156,7 +156,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
     A <a>script resource</a> has an associated <dfn export for="script resource" id="dfn-referrer-policy">referrer policy</dfn> (a [=/referrer policy=]). It is initially the empty string.
 
-    A [=/service worker=] has an associated <dfn export id="dfn-script-resource-map">script resource map</dfn> which is an <a>ordered map</a> where the keys are [=/URLs=] and the values are [=/responses=].
+    A [=script resource=] has an associated <dfn export for="script resource" id="dfn-script-resource-map">imported scripts map</dfn> which is an <a>ordered map</a> where the keys are [=/URLs=] and the values are [=/responses=].
 
     A [=/service worker=] has an associated <dfn export id="dfn-skip-waiting-flag">skip waiting flag</dfn>. Unless stated otherwise it is unset.
 
@@ -2159,10 +2159,10 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
             1. Let |response| be the result of <a lt="fetch">fetching</a> |request|.
             1. If |response|’s <a for="response" href="https://github.com/whatwg/fetch/issues/376">cache state</a> is not "<code>local</code>", set |registration|’s [=service worker registration/last update check time=] to the current time.
             1. If |response|'s <a>unsafe response</a>'s [=response/type=] is not "<code>error</code>", and |response|'s [=response/status=] is an <a>ok status</a>, then:
-                1. [=map/Set=] <a>script resource map</a>[|request|'s [=request/url=]] to |response|
+                1. [=map/Set=] |serviceWorker|'s [=script resource=]'s [=script resource/imported scripts map=][|request|'s [=request/url=]] to |response|.
             1. Return |response|.
         1. Else:
-            1. If <a>script resource map</a>[|url|] [=map/exists=], return <a>script resource map</a>[|url|].
+            1. If |serviceWorker|'s [=script resource=]'s [=script resource/imported scripts map=][|url|] [=map/exists=], return |serviceWorker|'s [=script resource=]'s [=script resource/imported scripts map=][|url|].
             1. Else, return a <a>network error</a>.
     </section>
   </section>
@@ -2190,7 +2190,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
   <section>
     <h3 id="privacy">Privacy</h3>
 
-    [=/Service workers=] introduce new persistent storage features including <a>scope to registration map</a> (for [=/service worker registrations=] and their [=/service workers=]), <a>request to response map</a> and <a>name to cache map</a> (for caches), and <a>script resource map</a> (for script resources). In order to protect users from any potential <a biblio data-biblio-type="informative" lt="unsanctioned-tracking">unsanctioned tracking</a> threat, these persistent storages *should* be cleared when users intend to clear them and *should* maintain and interoperate with existing user controls e.g. purging all existing persistent storages.
+    [=/Service workers=] introduce new persistent storage features including <a>scope to registration map</a> (for [=/service worker registrations=] and their [=/service workers=]), <a>request to response map</a> and <a>name to cache map</a> (for caches), and [=script resource/imported scripts map=] (for script resources). In order to protect users from any potential <a biblio data-biblio-type="informative" lt="unsanctioned-tracking">unsanctioned tracking</a> threat, these persistent storages *should* be cleared when users intend to clear them and *should* maintain and interoperate with existing user controls e.g. purging all existing persistent storages.
   </section>
 </section>
 
@@ -2529,7 +2529,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
           Else, continue the rest of these steps after the algorithm's asynchronous completion, with |script| being the asynchronous completion value.
 
-      1. If |newestWorker| is not null, |newestWorker|'s [=service worker/script url=] [=url/equals=] |job|'s [=job/script url=] with the *exclude fragments flag* set, and |script|'s [=source text=] is a byte-for-byte match with |newestWorker|'s [=script resource=]'s [=source text=], if |script| is a [=classic script=], and |script|'s [=module script/module record=]'s \[[ECMAScriptCode]] is a byte-for-byte match with |newestWorker|'s [=script resource=]'s [=module script/module record=]'s \[[ECMAScriptCode]] otherwise, then:
+      1. If |newestWorker| is not null, |newestWorker|'s [=service worker/script url=] [=url/equals=] |job|'s [=job/script url=] with the *exclude fragments flag* set, and the result of invoking [=Check If Service Worker Resources Are Identical=] with |newestWorker|'s [=script resource=], |script|, |registration|, and |job| is true, then:
           1. Invoke <a>Resolve Job Promise</a> with |job| and the {{ServiceWorkerRegistration}} object which represents |registration|.
           1. Invoke <a>Finish Job</a> with |job| and abort these steps.
       1. Else:
@@ -3224,6 +3224,37 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
       1. Return |newestWorker|.
   </section>
 
+  <section algorithm>
+    <h3 id="check-if-service-worker-resources-are-identical-algorithm"><dfn>Check If Service Worker Resources Are Identical</dfn></h3>
+
+      : Input
+      :: |sourceScript|, a [=script=]
+      :: |targetScript|, a [=script=]
+      :: |registration|, a [=/service worker registration=]
+      :: |job|, a [=job=]
+      : Output
+      :: True or false, a boolean
+
+      1. If |sourceScript| and |targetScript| are not both [=classic scripts=] or not both [=module scripts=], return false.
+      1. If |sourceScript| is a [=classic script=], then:
+          1. If |sourceScript|'s [=source text=] is not a byte-for-byte match with |targetScript|'s [=source text=], return false.
+          1. Let |sourceMap| be |sourceScript|'s [=script resource/imported scripts map=].
+          1. [=map/For each=] |url| → |response| of |sourceMap|:
+              1. Let |request| be a new [=/request=] whose [=request/url=] is |url|, [=request/client=] is |job|'s [=job/client=], [=request/type=] is "<code>script</code>", [=request/destination=] is "<code>script</code>", [=request/parser metadata=] is "<code>not parser-inserted</code>", [=request/synchronous flag=] is set, and whose [=request/use-URL-credentials flag=] is set.
+              1. Set |request|'s [=request/cache mode=] to "<code>no-cache</code>" if any of the following are true:
+                  * |registration|'s [=service worker registration/use cache=] is false.
+                  * |job|'s [=force bypass cache flag=] is set.
+                  * |registration|'s [=last update check time=] is not null and the time difference in seconds calculated by the current time minus |registration|’s [=last update check time=] is greater than 86400.
+              1. Let |targetResponse| be the result of [=fetch|fetching=] |request|.
+              1. If |targetResponse|'s <a for="response" href="https://github.com/whatwg/fetch/issues/376">cache state</a> is not "<code>local</code>", set |registration|’s [=last update check time=] to the current time.
+              1. Let |targetResponse| be |targetResponse|'s [=unsafe response=].
+              1. If |targetResponse|'s [=response/type=] is "<code>error</code>", or |targetResponse|'s [=response/status=] is not an [=ok status=], return false.
+              1. If the result of [=UTF-8 decoding=] |response|'s [=response/body=] is not a byte-for-byte match with the result of [=UTF-8 decoding=] |targetResponse|'s [=response/body=], return false.
+      1. If |sourceScript| is a [=module script=], then:
+          1. If |sourceScript|’s [=module script/module record=]'s \[[ECMAScriptCode]] is not a byte-for-byte match with |targetScript|’s [=module script/module record=]'s \[[ECMAScriptCode]], return false.
+      1. Return true.
+  </section>
+
   <section algorithm>
     <h3 id="create-client-algorithm"><dfn>Create Client</dfn></h3>