archive old.reddit links when given new reddit link

reddit-sub.js

@@ -0,0 +1,61 @@
+class RedditNewOld
+{
+  // required: an id for this behavior, will be displayed in the logs
+  // when the behavior is run.
+  static id = "reddit-new-old";
+
+  // required: a function that checks if a behavior should be run
+  // for a given page.
+  // This function can check the DOM / window.location to determine
+  // what page it is on. The first behavior that returns 'true'
+  // for a given page is used on that page.
+  static isMatch() {
+    return window.location.href.match(
+      /https:\/\/(www\.)?reddit\.com\/r\/[A-Za-z0-9]+(\/?$|best|hot|new|rising|top\/?(\?t=(hour|day|week|month|year|all))?|\/comments\/.+)$/
+    );
+  }
+
+  // required: typically should be left as-is.
+  // must return an object, with optional fields:
+  //   state: passes fixed state to behavior context (ctx)
+  //   opts: passes options to behavior context (ctx). this may be
+  // useful when injecting behaviors directly into the browser, and
+  // provides a basis for passing options to custom behaviors from
+  // browsertrix and archiveweb.page in the future.
+  static init() {
+    return {};
+  }
+
+  // optional: if true, will also check isMatch() and possibly run
+  // this behavior in each iframe.
+  // if false, or not defined, this behavior will be skipped for iframes.
+  static runInIframe = false;
+
+  // optional: if defined, provides a way to define a custom way to determine
+  // when a page has finished loading beyond the standard 'load' event.
+  //
+  // if defined, the crawler will await 'awaitPageLoad()' before moving on to
+  // post-crawl processing operations, including link extraction, screenshots,
+  // and running main behavior
+  async awaitPageLoad() {
+
+  }
+
+  // required: the main behavior async iterator, which should yield for
+  // each 'step' in the behavior.
+  // When the iterator finishes, the behavior is done.
+  // (See below for more info)
+  async* run(ctx) {
+    const { Lib } = ctx;
+
+    // archive the old view of the subreddit as well
+    const url = new URL(window.location.href)
+    if (url.hostname === "reddit.com" || url.hostname === "www.reddit.com") {
+      url.hostname = "old.reddit.com";
+    }
+    const old_url = url.toString();
+
+    await Lib.addLink(old_url);
+    yield Lib.getState(ctx, "old-reddit link added to queue");
+  }
+}