1 files changed, 101 insertions, 0 deletions
diff --git a/node_modules/jsdom/lib/jsdom/living/nodes/HTMLLinkElement-impl.js b/node_modules/jsdom/lib/jsdom/living/nodes/HTMLLinkElement-impl.js
new file mode 100644
index 0000000..53e0b67
--- /dev/null
+++ b/node_modules/jsdom/lib/jsdom/living/nodes/HTMLLinkElement-impl.js
@@ -0,0 +1,101 @@
+"use strict";
+const DOMTokenList = require("../generated/DOMTokenList");
+const HTMLElementImpl = require("./HTMLElement-impl").implementation;
+const idlUtils = require("../generated/utils");
+const { fetchStylesheet } = require("../helpers/stylesheets");
+const { parseURLToResultingURLRecord } = require("../helpers/document-base-url");
+const whatwgURL = require("whatwg-url");
+
+// Important reading: "appropriate times to obtain the resource" in
+// https://html.spec.whatwg.org/multipage/semantics.html#link-type-stylesheet
+
+class HTMLLinkElementImpl extends HTMLElementImpl {
+  constructor(globalObject, args, privateData) {
+    super(globalObject, args, privateData);
+
+    this.sheet = null;
+  }
+
+  get relList() {
+    if (this._relList === undefined) {
+      this._relList = DOMTokenList.createImpl(this._globalObject, [], {
+        element: this,
+        attributeLocalName: "rel",
+        supportedTokens: new Set(["stylesheet"])
+      });
+    }
+    return this._relList;
+  }
+
+  _attach() {
+    super._attach();
+    maybeFetchAndProcess(this);
+  }
+
+  _attrModified(name, value, oldValue) {
+    super._attrModified(name, value, oldValue);
+
+    if (name === "href") { // TODO crossorigin="" or type=""
+      maybeFetchAndProcess(this);
+    }
+
+    if (name === "rel" && this._relList !== undefined) {
+      this._relList.attrModified();
+    }
+  }
+
+  get _accept() {
+    return "text/css,*/*;q=0.1";
+  }
+}
+
+module.exports = {
+  implementation: HTMLLinkElementImpl
+};
+
+// https://html.spec.whatwg.org/multipage/links.html#link-type-stylesheet
+function maybeFetchAndProcess(el) {
+  if (!isExternalResourceLink(el)) {
+    return;
+  }
+
+  // Browsing-context connected
+  if (!el.isConnected || !el._ownerDocument._defaultView) {
+    return;
+  }
+
+  fetchAndProcess(el);
+}
+
+// https://html.spec.whatwg.org/multipage/semantics.html#default-fetch-and-process-the-linked-resource
+// TODO: refactor into general link-fetching like the spec.
+function fetchAndProcess(el) {
+  const href = el.getAttributeNS(null, "href");
+
+  if (href === null || href === "") {
+    return;
+  }
+
+  const url = parseURLToResultingURLRecord(href, el._ownerDocument);
+  if (url === null) {
+    return;
+  }
+
+  // TODO handle crossorigin="", nonce, integrity="", referrerpolicy=""
+
+  const serialized = whatwgURL.serializeURL(url);
+
+  fetchStylesheet(el, serialized);
+}
+
+function isExternalResourceLink(el) {
+  // for our purposes, only stylesheets can be external resource links
+  const wrapper = idlUtils.wrapperForImpl(el);
+  if (!/(?:[ \t\n\r\f]|^)stylesheet(?:[ \t\n\r\f]|$)/i.test(wrapper.rel)) {
+    // rel is a space-separated list of tokens, and the original rel types
+    // are case-insensitive.
+    return false;
+  }
+
+  return el.hasAttributeNS(null, "href");
+}