fix: unbreak search()ed post comments yet again

The previous fix for comment replies broke top level comments. This
fixes that issue. I hate Reddit's REST API so much.

Fixes thislooksfun#71

src/reddit/comment/listing/listing.ts

@@ -11,6 +11,7 @@ import { makeDebug } from "../../../helper/debug";
 import { Listing } from "../../listing/listing";
 import { MoreComments } from "./more";
 import { CommentPager } from "./pager";
+import { PostComments } from "./post";
 
 const debug = makeDebug("listing:comment");
 
@@ -21,15 +22,10 @@ function makeFetcher(
   if (after == undefined) return undefined;
 
   if (after === "" && context.post) {
-    return new MoreComments({
-      children: [],
-      count: 0,
-      depth: 0,
-      id: "_",
-      name: "t1__",
-      // eslint-disable-next-line @typescript-eslint/naming-convention
-      parent_id: context.client.posts.namespace(context.post),
-    });
+    // HACK: Some posts, notably the ones returned by search, don't have their
+    // own comments listing. To ensure we can still get comments for those posts
+    // we use a custom fetcher that just jump-starts the fetching process.
+    return new PostComments();
   }
 
   return new CommentPager(after);

src/reddit/comment/listing/post.ts

@@ -0,0 +1,28 @@
+import type {
+  Fetcher,
+  ListingContext,
+  ListingObject,
+} from "../../listing/listing";
+import type { Comment } from "../object";
+
+import { emptyRedditListing } from "../../listing/util";
+import { CommentListing } from "./listing";
+
+/** @internal */
+export class PostComments implements Fetcher<Comment> {
+  async fetch(context: ListingContext): Promise<CommentListing> {
+    if (!context.post) {
+      // This should never happen, but just in case...
+      throw new Error("Precondition failed: context.post is falsy");
+    }
+
+    const pth = `comments/${context.post}`;
+    const childrenResponse: [unknown, ListingObject] =
+      await context.client.gateway.get(pth, { comment: context.post });
+
+    return new CommentListing(
+      childrenResponse[1].data ?? emptyRedditListing,
+      context
+    );
+  }
+}