Updating steps and fixing error

Author: KurtCattiSchmidt

source

@@ -68414,32 +68414,10 @@ interface <dfn interface>HTMLTemplateElement</dfn> : <span>HTMLElement</span> {
       data-x="concept-settings-object-module-map">module map</span>.</p></li>
       <li><p>Let <var>moduleScript</var> be
       <var>moduleMap</var>[(<var>url</var>, <var>moduleType</var>)].</p></li>
-      <li><p>If <var>moduleScript</var> is null:</p>
-        <ul>
-          <li><p>Set <var>moduleScript</var> to the result of <span
-          data-x="creating a CSS module script">create a CSS module script</span> with an empty
-          <var>source</var> and <var>settingsObject</var>.</p></li>
-          <li><p>Set <var>moduleMap</var>[(<var>url</var>, <var>moduleType</var>)] to
-          <var>moduleScript</var>.</p></li>
-          <li><p><span>Fetch a single module script</span> given <var>url</var>,
-          <var>settingsObject</var>, "<code data-x="">style</code>", the
-          <span>default script fetch options</span>, <var>settingsObject</var>, "<code
-          data-x="">client</code>", true, and with the following steps given <var>result</var>:</p>
-            <ul>
-              <li><p>If <var>result</var> is null, then abort these steps.</p></li>
-              <li><p>Let <var>fetchedSheet</var> be the <code>CSSStyleSheet</code> extracted from
-              <var>result</var>'s <span
-              data-x="concept-script-record">record</span>.</p></li>
-              <li><p>Let <var>existingSheet</var> be the <code>CSSStyleSheet</code> extracted from
-              <var>moduleScript</var>'s <span
-              data-x="concept-script-record">record</span>.</p></li>
-              <li><p>Call <span>replaceSync</span> on <var>existingSheet</var> given the
-              <span data-x="concept-CSSStyleSheet-CSS-text">CSS text</span> of
-              <var>fetchedSheet</var>.</p></li>
-            </ul>
-          </li>
-        </ul>
-      </li>
+      <li><p>If <var>moduleScript</var> is null, <span>fetch a single module script</span> given
+      <var>url</var>, <var>settingsObject</var>, "<code data-x="">style</code>", the
+      <span>default script fetch options</span>, <var>settingsObject</var>, "<code
+      data-x="">client</code>", true</p></li>
       <li><p>Extract the <code>CSSStyleSheet</code> from <var>moduleScript</var>'s
       <span data-x="concept-script-record">record</span> and append it to
       <var>adoptedStyleSheets</var>. If any error occurs, then <span>continue</span>.</p></li>
@@ -117574,6 +117552,16 @@ document.querySelector("button").addEventListener("click", bound);
    <li><p><span data-x="map set">Set</span> <var>moduleMap</var>[(<var>url</var>,
    <var>moduleType</var>)] to "<code data-x="">fetching</code>".</p></li>
 
+   <li><p>If <var>destination</var> is "<code data-x="">style</code>", then:</p>
+    <ol>
+      <li><p>Let <var>emptyStyleScript</var> be the result of <span>creating a CSS module
+      script</span> with an empty <var>source</var> and <var>settingsObject</var></p></li>
+      <li><p><span data-x="map set">set</span> <var>moduleMap</var>[(<var>url</var>,
+      <var>moduleType</var>)] to <var>emptyStyleScript</var>, retaining the "<code
+      data-x="">fetching</code>" status.</p></li>
+    </ol>
+  </li>
+
    <li><p>Let <var>request</var> be a new <span data-x="concept-request">request</span> whose
    <span data-x="concept-request-url">URL</span> is <var>url</var>, <span
    data-x="concept-request-mode">mode</span> is "<code data-x="">cors</code>", <span
@@ -117666,8 +117654,8 @@ document.querySelector("button").addEventListener("click", bound);
 
        <li><p>If the <span>MIME type essence</span> of <var>mimeType</var> is "<code>text/css</code>"
        and <var>moduleType</var> is "<code data-x="">css</code>", then set <var>moduleScript</var> to
-       the result of <span>creating a CSS module script</span> given <var>sourceText</var> and
-       <var>settingsObject</var>.</p></li>
+       the result of <span>updating a CSS module script</span> given <var>sourceText</var> and
+       <var>moduleMap</var>[(<var>url</var>,<var>moduleType</var>)].</p></li>
 
        <li><p>If <var>mimeType</var> is a <span>JSON MIME type</span> and
        <var>moduleType</var> is "<code data-x="">json</code>", then set <var>moduleScript</var> to
@@ -117978,6 +117966,32 @@ document.querySelector("button").addEventListener("click", bound);
   </ol>
   </div>
 
+  <div algorithm>
+  <p>To <dfn data-x="updating a CSS module script">update a CSS module script</dfn>, given a
+  string <var>source</var> and a <var>script</var> <span>module script</span> :</p>
+
+  <ol>
+   <li><p>Let <var>sheet</var> be the default export of <var>script</var></p></li>
+
+   <li>
+    <p>Run the steps to <span>synchronously replace the rules of a <code>CSSStyleSheet</code></span>
+    on <var>sheet</var> given <var>source</var>.</p>
+
+    <p>If this throws an exception, catch it, and set <var>script</var>'s <span
+    data-x="concept-script-parse-error">parse error</span> to that exception, and return
+    <var>script</var>.</p>
+
+    <p class="note">The steps to <span>synchronously replace the rules of a
+    <code>CSSStyleSheet</code></span> will throw if <var>source</var> contains any <code
+    data-x="">@import</code> rules.  This is by-design for now because there is not yet an
+    agreement on how to handle these for CSS module scripts; therefore they are blocked altogether
+    until a consensus is reached.</p>
+   </li>
+
+   <li><p>Return <var>script</var>.</p></li>
+  </ol>
+  </div>
+
   <div algorithm>
   <p>To <dfn data-x="creating a JSON module script">create a JSON module script</dfn>, given a
   string <var>source</var> and an <span>environment settings object</span> <var>settings</var>:</p>