osr-discourse-src/app/assets/javascripts/discourse/tests/unit/models/post-stream-test.js

import { module, test } from "qunit";
import ArrayProxy from "@ember/array/proxy";
import Post from "discourse/models/post";
import User from "discourse/models/user";
import pretender, { response } from "discourse/tests/helpers/create-pretender";
import sinon from "sinon";
import { getOwner } from "discourse-common/lib/get-owner";
import { setupTest } from "ember-qunit";

function buildStream(id, stream) {
  const store = getOwner(this).lookup("service:store");
  const topic = store.createRecord("topic", { id, chunk_size: 5 });

  if (stream) {
    topic.postStream.set("stream", stream);
  }

  return topic.postStream;
}

const participant = { username: "eviltrout" };

module("Unit | Model | post-stream", function (hooks) {
  setupTest(hooks);

  test("create", function (assert) {
    const store = getOwner(this).lookup("service:store");
    assert.ok(
      store.createRecord("postStream"),
      "it can be created with no parameters"
    );
  });

  test("defaults", function (assert) {
    const postStream = buildStream.call(this, 1234);
    assert.blank(postStream.posts, "there are no posts in a stream by default");
    assert.ok(!postStream.loaded, "it has never loaded");
    assert.present(postStream.topic);
  });

  test("appending posts", function (assert) {
    const postStream = buildStream.call(this, 4567, [1, 3, 4]);
    const store = getOwner(this).lookup("service:store");

    assert.strictEqual(postStream.lastPostId, 4, "the last post id is 4");

    assert.ok(!postStream.hasPosts, "there are no posts by default");
    assert.ok(!postStream.firstPostPresent, "the first post is not loaded");
    assert.ok(!postStream.loadedAllPosts, "the last post is not loaded");
    assert.strictEqual(postStream.posts.length, 0, "it has no posts initially");

    postStream.appendPost(
      store.createRecord("post", { id: 2, post_number: 2 })
    );
    assert.ok(
      !postStream.firstPostPresent,
      "the first post is still not loaded"
    );
    assert.strictEqual(
      postStream.posts.length,
      1,
      "it has one post in the stream"
    );

    postStream.appendPost(
      store.createRecord("post", { id: 4, post_number: 4 })
    );
    assert.ok(!postStream.firstPostPresent, "the first post is still loaded");
    assert.ok(postStream.loadedAllPosts, "the last post is now loaded");
    assert.strictEqual(
      postStream.posts.length,
      2,
      "it has two posts in the stream"
    );

    postStream.appendPost(
      store.createRecord("post", { id: 4, post_number: 4 })
    );
    assert.strictEqual(
      postStream.posts.length,
      2,
      "it will not add the same post with id twice"
    );

    const stagedPost = store.createRecord("post", { raw: "incomplete post" });
    postStream.appendPost(stagedPost);
    assert.strictEqual(
      postStream.posts.length,
      3,
      "it can handle posts without ids"
    );
    postStream.appendPost(stagedPost);
    assert.strictEqual(
      postStream.posts.length,
      3,
      "it won't add the same post without an id twice"
    );

    // change the stream
    postStream.set("stream", [1, 2, 4]);
    assert.ok(
      !postStream.firstPostPresent,
      "the first post no longer loaded since the stream changed."
    );
    assert.ok(
      postStream.loadedAllPosts,
      "the last post is still the last post in the new stream"
    );
  });

  test("closestPostNumberFor", function (assert) {
    const postStream = buildStream.call(this, 1231);
    const store = getOwner(this).lookup("service:store");

    assert.blank(
      postStream.closestPostNumberFor(1),
      "there is no closest post when nothing is loaded"
    );

    postStream.appendPost(
      store.createRecord("post", { id: 1, post_number: 2 })
    );
    postStream.appendPost(
      store.createRecord("post", { id: 2, post_number: 3 })
    );

    assert.strictEqual(
      postStream.closestPostNumberFor(2),
      2,
      "If a post is in the stream it returns its post number"
    );
    assert.strictEqual(
      postStream.closestPostNumberFor(3),
      3,
      "If a post is in the stream it returns its post number"
    );
    assert.strictEqual(
      postStream.closestPostNumberFor(10),
      3,
      "it clips to the upper bound of the stream"
    );
    assert.strictEqual(
      postStream.closestPostNumberFor(0),
      2,
      "it clips to the lower bound of the stream"
    );
  });

  test("closestDaysAgoFor", function (assert) {
    const postStream = buildStream.call(this, 1231);
    postStream.set("timelineLookup", [
      [1, 10],
      [3, 8],
      [5, 1],
    ]);

    assert.strictEqual(postStream.closestDaysAgoFor(1), 10);
    assert.strictEqual(postStream.closestDaysAgoFor(2), 10);
    assert.strictEqual(postStream.closestDaysAgoFor(3), 8);
    assert.strictEqual(postStream.closestDaysAgoFor(4), 8);
    assert.strictEqual(postStream.closestDaysAgoFor(5), 1);

    // Out of bounds
    assert.strictEqual(postStream.closestDaysAgoFor(-1), 10);
    assert.strictEqual(postStream.closestDaysAgoFor(0), 10);
    assert.strictEqual(postStream.closestDaysAgoFor(10), 1);

    postStream.set("timelineLookup", []);
    assert.strictEqual(postStream.closestDaysAgoFor(1), undefined);
  });

  test("closestDaysAgoFor - empty", function (assert) {
    const postStream = buildStream.call(this, 1231);
    postStream.set("timelineLookup", []);

    assert.strictEqual(postStream.closestDaysAgoFor(1), undefined);
  });

  test("updateFromJson", function (assert) {
    const postStream = buildStream.call(this, 1231);

    postStream.updateFromJson({
      posts: [{ id: 1 }],
      stream: [1],
      extra_property: 12,
    });

    assert.strictEqual(postStream.posts.length, 1, "it loaded the posts");
    assert.containsInstance(postStream.posts, Post);

    assert.strictEqual(postStream.extra_property, 12);
  });

  test("removePosts", function (assert) {
    const postStream = buildStream.call(this, 10000001, [1, 2, 3]);
    const store = getOwner(this).lookup("service:store");

    const p1 = store.createRecord("post", { id: 1, post_number: 2 }),
      p2 = store.createRecord("post", { id: 2, post_number: 3 }),
      p3 = store.createRecord("post", { id: 3, post_number: 4 });

    postStream.appendPost(p1);
    postStream.appendPost(p2);
    postStream.appendPost(p3);

    // Removing nothing does nothing
    postStream.removePosts();
    assert.strictEqual(postStream.posts.length, 3);

    postStream.removePosts([p1, p3]);
    assert.strictEqual(postStream.posts.length, 1);
    assert.deepEqual(postStream.stream, [2]);
  });

  test("cancelFilter", function (assert) {
    const postStream = buildStream.call(this, 1235);

    sinon.stub(postStream, "refresh").resolves();

    postStream.set("filter", "summary");
    postStream.cancelFilter();
    assert.ok(!postStream.summary, "summary is cancelled");

    postStream.filterParticipant(participant);
    postStream.cancelFilter();
    assert.blank(
      postStream.userFilters,
      "cancelling the filters clears the userFilters"
    );
  });

  test("findPostIdForPostNumber", function (assert) {
    const postStream = buildStream.call(
      this,
      1234,
      [10, 20, 30, 40, 50, 60, 70]
    );
    postStream.set("gaps", { before: { 60: [55, 58] } });

    assert.strictEqual(
      postStream.findPostIdForPostNumber(500),
      undefined,
      "it returns undefined when the post cannot be found"
    );
    assert.strictEqual(
      postStream.findPostIdForPostNumber(1),
      10,
      "it finds the postId at the beginning"
    );
    assert.strictEqual(
      postStream.findPostIdForPostNumber(5),
      50,
      "it finds the postId in the middle"
    );
    assert.strictEqual(
      postStream.findPostIdForPostNumber(8),
      60,
      "it respects gaps"
    );
  });

  test("fillGapBefore", function (assert) {
    const postStream = buildStream.call(this, 1234, [60]);
    sinon.stub(postStream, "findPostsByIds").resolves([]);
    const post = postStream.store.createRecord("post", {
      id: 60,
      post_number: 60,
    });
    postStream.set("gaps", {
      before: { 60: [51, 52, 53, 54, 55, 56, 57, 58, 59] },
    });

    postStream.fillGapBefore(post, [51, 52, 53, 54, 55, 56, 57, 58, 59]);

    assert.deepEqual(
      postStream.stream,
      [51, 52, 53, 54, 55, 60],
      "partial results are included in the stream"
    );
  });

  test("filterParticipant", function (assert) {
    const postStream = buildStream.call(this, 1236);
    sinon.stub(postStream, "refresh").resolves();

    assert.strictEqual(
      postStream.userFilters.length,
      0,
      "by default no participants are toggled"
    );

    postStream.filterParticipant(participant.username);
    assert.ok(
      postStream.userFilters.includes("eviltrout"),
      "eviltrout is in the filters"
    );

    postStream.cancelFilter();
    assert.blank(postStream.userFilters, "cancelFilter clears");
  });

  test("filterReplies", function (assert) {
    const postStream = buildStream.call(this, 1234),
      store = postStream.store;

    postStream.appendPost(
      store.createRecord("post", { id: 2, post_number: 3 })
    );

    sinon.stub(postStream, "refresh").resolves();

    assert.strictEqual(
      postStream.filterRepliesToPostNumber,
      false,
      "by default no replies are filtered"
    );

    postStream.filterReplies(3, 2);
    assert.strictEqual(
      postStream.filterRepliesToPostNumber,
      3,
      "postNumber is in the filters"
    );

    postStream.cancelFilter();
    assert.strictEqual(
      postStream.filterRepliesToPostNumber,
      false,
      "cancelFilter clears"
    );
  });

  test("filterUpwards", function (assert) {
    const postStream = buildStream.call(this, 1234),
      store = postStream.store;

    postStream.appendPost(
      store.createRecord("post", { id: 2, post_number: 3 })
    );

    sinon.stub(postStream, "refresh").resolves();

    assert.strictEqual(
      postStream.filterUpwardsPostID,
      false,
      "by default filter is false"
    );

    postStream.filterUpwards(2);
    assert.strictEqual(postStream.filterUpwardsPostID, 2, "filter is set");

    postStream.cancelFilter();
    assert.strictEqual(postStream.filterUpwardsPostID, false, "filter cleared");
  });

  test("streamFilters", function (assert) {
    const postStream = buildStream.call(this, 1237);
    sinon.stub(postStream, "refresh").resolves();

    assert.deepEqual(
      postStream.streamFilters,
      {},
      "there are no postFilters by default"
    );
    assert.ok(postStream.hasNoFilters, "there are no filters by default");

    postStream.set("filter", "summary");
    assert.deepEqual(
      postStream.streamFilters,
      { filter: "summary" },
      "postFilters contains the summary flag"
    );
    assert.ok(!postStream.hasNoFilters, "now there are filters present");

    postStream.filterParticipant(participant.username);
    assert.deepEqual(
      postStream.streamFilters,
      {
        username_filters: "eviltrout",
      },
      "streamFilters contains the username we filtered"
    );

    postStream.filterUpwards(2);
    assert.deepEqual(
      postStream.streamFilters,
      {
        filter_upwards_post_id: 2,
      },
      "streamFilters contains only the post ID"
    );

    postStream.filterReplies(1);
    assert.deepEqual(
      postStream.streamFilters,
      {
        replies_to_post_number: 1,
      },
      "streamFilters contains only the last filter"
    );
  });

  test("loading", function (assert) {
    const postStream = buildStream.call(this, 1234);
    assert.ok(!postStream.loading, "we're not loading by default");

    postStream.set("loadingAbove", true);
    assert.ok(postStream.loading, "we're loading if loading above");

    const postStream2 = buildStream.call(this, 1234);
    postStream2.set("loadingBelow", true);
    assert.ok(postStream2.loading, "we're loading if loading below");

    const postStream3 = buildStream.call(this, 1234);
    postStream3.set("loadingFilter", true);
    assert.ok(postStream3.loading, "we're loading if loading a filter");
  });

  test("nextWindow", function (assert) {
    const postStream = buildStream.call(
      this,
      1234,
      [1, 2, 3, 5, 8, 9, 10, 11, 13, 14, 15, 16]
    );

    assert.blank(
      postStream.nextWindow,
      "With no posts loaded, the window is blank"
    );

    postStream.updateFromJson({ posts: [{ id: 1 }, { id: 2 }] });
    assert.deepEqual(
      postStream.nextWindow,
      [3, 5, 8, 9, 10],
      "If we've loaded the first 2 posts, the window should be the 5 after that"
    );

    postStream.updateFromJson({ posts: [{ id: 13 }] });
    assert.deepEqual(
      postStream.nextWindow,
      [14, 15, 16],
      "Boundary check: stop at the end."
    );

    postStream.updateFromJson({ posts: [{ id: 16 }] });
    assert.blank(
      postStream.nextWindow,
      "Once we've seen everything there's nothing to load."
    );
  });

  test("previousWindow", function (assert) {
    const postStream = buildStream.call(
      this,
      1234,
      [1, 2, 3, 5, 8, 9, 10, 11, 13, 14, 15, 16]
    );

    assert.blank(
      postStream.previousWindow,
      "With no posts loaded, the window is blank"
    );

    postStream.updateFromJson({ posts: [{ id: 11 }, { id: 13 }] });
    assert.deepEqual(
      postStream.previousWindow,
      [3, 5, 8, 9, 10],
      "If we've loaded in the middle, it's the previous 5 posts"
    );

    postStream.updateFromJson({ posts: [{ id: 3 }] });
    assert.deepEqual(
      postStream.previousWindow,
      [1, 2],
      "Boundary check: stop at the beginning."
    );

    postStream.updateFromJson({ posts: [{ id: 1 }] });
    assert.blank(
      postStream.previousWindow,
      "Once we've seen everything there's nothing to load."
    );
  });

  test("storePost", function (assert) {
    const postStream = buildStream.call(this, 1234),
      store = postStream.store,
      post = store.createRecord("post", {
        id: 1,
        post_number: 100,
        raw: "initial value",
      });

    assert.blank(
      postStream.topic.highest_post_number,
      "it has no highest post number yet"
    );
    const stored = postStream.storePost(post);
    assert.strictEqual(post, stored, "it returns the post it stored");
    assert.strictEqual(
      post.topic,
      postStream.topic,
      "it creates the topic reference properly"
    );
    assert.strictEqual(
      postStream.topic.highest_post_number,
      100,
      "it set the highest post number"
    );

    const dupePost = store.createRecord("post", {
      id: 1,
      post_number: 100,
      raw: "updated value",
    });
    const storedDupe = postStream.storePost(dupePost);
    assert.strictEqual(
      storedDupe,
      post,
      "it returns the previously stored post instead to avoid dupes"
    );
    assert.strictEqual(
      storedDupe.raw,
      "updated value",
      "it updates the previously stored post"
    );

    const postWithoutId = store.createRecord("post", { raw: "hello world" });
    const stored2 = postStream.storePost(postWithoutId);
    assert.strictEqual(stored2, postWithoutId, "it returns the same post back");
  });

  test("identity map", async function (assert) {
    const postStream = buildStream.call(this, 1234);
    const store = getOwner(this).lookup("service:store");

    const p1 = postStream.appendPost(
      store.createRecord("post", { id: 1, post_number: 1 })
    );
    const p3 = postStream.appendPost(
      store.createRecord("post", { id: 3, post_number: 4 })
    );

    assert.strictEqual(
      postStream.findLoadedPost(1),
      p1,
      "it can return cached posts by id"
    );
    assert.blank(postStream.findLoadedPost(4), "it can't find uncached posts");

    // Find posts by ids uses the identity map
    const result = await postStream.findPostsByIds([1, 2, 3]);
    assert.strictEqual(result.length, 3);
    assert.strictEqual(result.objectAt(0), p1);
    assert.strictEqual(result.objectAt(1).post_number, 2);
    assert.strictEqual(result.objectAt(2), p3);
  });

  test("loadIntoIdentityMap with no data", async function (assert) {
    const result = await buildStream.call(this, 1234).loadIntoIdentityMap([]);
    assert.strictEqual(
      result.length,
      0,
      "requesting no posts produces no posts"
    );
  });

  test("loadIntoIdentityMap with post ids", async function (assert) {
    const postStream = buildStream.call(this, 1234);
    await postStream.loadIntoIdentityMap([10]);

    assert.present(
      postStream.findLoadedPost(10),
      "it adds the returned post to the store"
    );
  });

  test("appendMore for megatopic", async function (assert) {
    const postStream = buildStream.call(this, 1234);
    const store = getOwner(this).lookup("service:store");
    const post = store.createRecord("post", { id: 1, post_number: 1 });

    postStream.setProperties({
      isMegaTopic: true,
      posts: [post],
    });

    await postStream.appendMore();
    assert.present(
      postStream.findLoadedPost(2),
      "it adds the returned post to the store"
    );

    assert.strictEqual(
      postStream.posts.length,
      6,
      "it adds the right posts into the stream"
    );
  });

  test("prependMore for megatopic", async function (assert) {
    const postStream = buildStream.call(this, 1234);
    const store = getOwner(this).lookup("service:store");
    const post = store.createRecord("post", { id: 6, post_number: 6 });

    postStream.setProperties({
      isMegaTopic: true,
      posts: [post],
    });

    await postStream.prependMore();
    assert.present(
      postStream.findLoadedPost(5),
      "it adds the returned post to the store"
    );

    assert.strictEqual(
      postStream.posts.length,
      6,
      "it adds the right posts into the stream"
    );
  });

  test("staging and undoing a new post", function (assert) {
    const postStream = buildStream.call(this, 10101, [1]);
    const store = getOwner(this).lookup("service:store");

    const original = store.createRecord("post", {
      id: 1,
      post_number: 1,
      topic_id: 10101,
    });
    postStream.appendPost(original);
    assert.strictEqual(
      postStream.lastAppended,
      original,
      "the original post is lastAppended"
    );

    const user = store.createRecord("user", {
      username: "eviltrout",
      name: "eviltrout",
      id: 321,
    });
    const stagedPost = store.createRecord("post", {
      raw: "hello world this is my new post",
      topic_id: 10101,
    });

    const topic = postStream.topic;
    topic.setProperties({
      posts_count: 1,
      highest_post_number: 1,
    });

    // Stage the new post in the stream
    const result = postStream.stagePost(stagedPost, user);
    assert.strictEqual(result, "staged", "it returns staged");
    assert.strictEqual(
      topic.highest_post_number,
      2,
      "it updates the highest_post_number"
    );
    assert.ok(
      postStream.loading,
      "it is loading while the post is being staged"
    );
    assert.strictEqual(
      postStream.lastAppended,
      original,
      "it doesn't consider staged posts as the lastAppended"
    );

    assert.strictEqual(topic.posts_count, 2, "it increases the post count");
    assert.present(topic.last_posted_at, "it updates last_posted_at");
    assert.strictEqual(
      topic.details.last_poster,
      user,
      "it changes the last poster"
    );

    assert.strictEqual(
      stagedPost.topic,
      topic,
      "it assigns the topic reference"
    );
    assert.strictEqual(
      stagedPost.post_number,
      2,
      "it is assigned the probable post_number"
    );
    assert.present(stagedPost.created_at, "it is assigned a created date");
    assert.ok(
      postStream.posts.includes(stagedPost),
      "the post is added to the stream"
    );
    assert.strictEqual(stagedPost.id, -1, "the post has a magical -1 id");

    // Undoing a created post (there was an error)
    postStream.undoPost(stagedPost);

    assert.ok(!postStream.loading, "it is no longer loading");
    assert.strictEqual(
      topic.highest_post_number,
      1,
      "it reverts the highest_post_number"
    );
    assert.strictEqual(topic.posts_count, 1, "it reverts the post count");
    assert.strictEqual(
      postStream.filteredPostsCount,
      1,
      "it retains the filteredPostsCount"
    );
    assert.ok(
      !postStream.posts.includes(stagedPost),
      "the post is removed from the stream"
    );
    assert.strictEqual(
      postStream.lastAppended,
      original,
      "it doesn't consider undid post lastAppended"
    );
  });

  test("staging and committing a post", function (assert) {
    const postStream = buildStream.call(this, 10101, [1]);
    const store = getOwner(this).lookup("service:store");

    const original = store.createRecord("post", {
      id: 1,
      post_number: 1,
      topic_id: 10101,
    });
    postStream.appendPost(original);
    assert.strictEqual(
      postStream.lastAppended,
      original,
      "the original post is lastAppended"
    );

    const user = store.createRecord("user", {
      username: "eviltrout",
      name: "eviltrout",
      id: 321,
    });
    const stagedPost = store.createRecord("post", {
      raw: "hello world this is my new post",
      topic_id: 10101,
    });

    const topic = postStream.topic;
    topic.set("posts_count", 1);

    // Stage the new post in the stream
    const result = postStream.stagePost(stagedPost, user);
    assert.strictEqual(result, "staged", "it returns staged");

    assert.ok(
      postStream.loading,
      "it is loading while the post is being staged"
    );
    stagedPost.setProperties({ id: 1234, raw: "different raw value" });

    const result2 = postStream.stagePost(stagedPost, user);
    assert.strictEqual(
      result2,
      "alreadyStaging",
      "you can't stage a post while it is currently staging"
    );
    assert.strictEqual(
      postStream.lastAppended,
      original,
      "staging a post doesn't change the lastAppended"
    );

    postStream.commitPost(stagedPost);
    assert.ok(
      postStream.posts.includes(stagedPost),
      "the post is still in the stream"
    );
    assert.ok(!postStream.loading, "it is no longer loading");

    assert.strictEqual(
      postStream.filteredPostsCount,
      2,
      "it increases the filteredPostsCount"
    );

    const found = postStream.findLoadedPost(stagedPost.id);
    assert.present(found, "the post is in the identity map");
    assert.ok(
      postStream.posts.includes(stagedPost),
      "the post is in the stream"
    );
    assert.strictEqual(
      found.raw,
      "different raw value",
      "it also updated the value in the stream"
    );
    assert.strictEqual(
      postStream.lastAppended,
      found,
      "committing a post changes lastAppended"
    );
  });

  test("loadedAllPosts when the id changes", function (assert) {
    // This can happen in a race condition between staging a post and it coming through on the
    // message bus. If the id of a post changes we should reconsider the loadedAllPosts property.
    const postStream = buildStream.call(this, 10101, [1, 2]);
    const store = getOwner(this).lookup("service:store");
    const postWithoutId = store.createRecord("post", {
      raw: "hello world this is my new post",
    });

    postStream.appendPost(
      store.createRecord("post", { id: 1, post_number: 1 })
    );
    postStream.appendPost(postWithoutId);
    assert.ok(!postStream.loadedAllPosts, "the last post is not loaded");

    postWithoutId.set("id", 2);
    assert.ok(
      postStream.loadedAllPosts,
      "the last post is loaded now that the post has an id"
    );
  });

  test("triggerRecoveredPost", async function (assert) {
    const postStream = buildStream.call(this, 4567);
    const store = getOwner(this).lookup("service:store");

    [1, 2, 3, 5].forEach((id) => {
      postStream.appendPost(
        store.createRecord("post", { id, post_number: id })
      );
    });

    pretender.get("/posts/4", () => {
      return response({ id: 4, post_number: 4 });
    });

    assert.strictEqual(
      postStream.postsWithPlaceholders.length,
      4,
      "it should return the right length"
    );

    await postStream.triggerRecoveredPost(4);

    assert.strictEqual(
      postStream.postsWithPlaceholders.length,
      5,
      "it should return the right length"
    );
  });

  test("committing and triggerNewPostsInStream race condition", function (assert) {
    const postStream = buildStream.call(this, 4964);
    const store = getOwner(this).lookup("service:store");

    postStream.appendPost(
      store.createRecord("post", { id: 1, post_number: 1 })
    );
    const user = store.createRecord("user", {
      username: "eviltrout",
      name: "eviltrout",
      id: 321,
    });
    const stagedPost = store.createRecord("post", {
      raw: "hello world this is my new post",
    });

    postStream.stagePost(stagedPost, user);
    assert.strictEqual(
      postStream.filteredPostsCount,
      0,
      "it has no filteredPostsCount yet"
    );
    stagedPost.set("id", 123);

    sinon.stub(postStream, "appendMore");
    postStream.triggerNewPostsInStream([123]);
    assert.strictEqual(postStream.filteredPostsCount, 1, "it added the post");

    postStream.commitPost(stagedPost);
    assert.strictEqual(
      postStream.filteredPostsCount,
      1,
      "it does not add the same post twice"
    );
  });

  test("triggerNewPostInStream for ignored posts", async function (assert) {
    const postStream = buildStream.call(this, 280, [1]);
    const store = getOwner(this).lookup("service:store");
    User.resetCurrent(
      store.createRecord("user", {
        username: "eviltrout",
        name: "eviltrout",
        id: 321,
        ignored_users: ["ignored-user"],
      })
    );

    postStream.appendPost(
      store.createRecord("post", { id: 1, post_number: 1 })
    );

    const post2 = store.createRecord("post", {
      id: 101,
      post_number: 2,
      username: "regular-user",
    });

    const post3 = store.createRecord("post", {
      id: 102,
      post_number: 3,
      username: "ignored-user",
    });

    const stub = sinon.stub(postStream, "findPostsByIds").resolves([post2]);

    await postStream.triggerNewPostsInStream([101]);
    assert.strictEqual(
      postStream.posts.length,
      2,
      "it added the regular post to the posts"
    );
    assert.strictEqual(
      postStream.stream.length,
      2,
      "it added the regular post to the stream"
    );

    stub.restore();
    sinon.stub(postStream, "findPostsByIds").resolves([post3]);

    await postStream.triggerNewPostsInStream([102]);
    assert.strictEqual(
      postStream.posts.length,
      2,
      "it does not add the ignored post to the posts"
    );
    assert.strictEqual(
      postStream.stream.length,
      2,
      "it does not add the ignored post to the stream"
    );
  });

  test("postsWithPlaceholders", async function (assert) {
    const postStream = buildStream.call(
      this,
      4964,
      [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
    );
    const postsWithPlaceholders = postStream.postsWithPlaceholders;
    const store = getOwner(this).lookup("service:store");

    const testProxy = ArrayProxy.create({ content: postsWithPlaceholders });

    const p1 = store.createRecord("post", { id: 1, post_number: 1 });
    const p2 = store.createRecord("post", { id: 2, post_number: 2 });
    const p3 = store.createRecord("post", { id: 3, post_number: 3 });
    const p4 = store.createRecord("post", { id: 4, post_number: 4 });

    postStream.appendPost(p1);
    postStream.appendPost(p2);
    postStream.appendPost(p3);

    // Test enumerable and array access
    assert.strictEqual(postsWithPlaceholders.length, 3);
    assert.strictEqual(testProxy.length, 3);
    assert.strictEqual(postsWithPlaceholders.nextObject(0), p1);
    assert.strictEqual(postsWithPlaceholders.objectAt(0), p1);
    assert.strictEqual(postsWithPlaceholders.nextObject(1, p1), p2);
    assert.strictEqual(postsWithPlaceholders.objectAt(1), p2);
    assert.strictEqual(postsWithPlaceholders.nextObject(2, p2), p3);
    assert.strictEqual(postsWithPlaceholders.objectAt(2), p3);

    const promise = postStream.appendMore();
    assert.strictEqual(
      postsWithPlaceholders.length,
      8,
      "we immediately have a larger placeholder window"
    );
    assert.strictEqual(testProxy.length, 8);
    assert.ok(!!postsWithPlaceholders.nextObject(3, p3));
    assert.ok(!!postsWithPlaceholders.objectAt(4));
    assert.ok(postsWithPlaceholders.objectAt(3) !== p4);
    assert.ok(testProxy.objectAt(3) !== p4);

    await promise;
    assert.strictEqual(postsWithPlaceholders.objectAt(3), p4);
    assert.strictEqual(
      postsWithPlaceholders.length,
      8,
      "have a larger placeholder window when loaded"
    );
    assert.strictEqual(testProxy.length, 8);
    assert.strictEqual(testProxy.objectAt(3), p4);
  });

  test("filteredPostsCount", function (assert) {
    const postStream = buildStream.call(this, 4567, [1, 3, 4]);

    assert.strictEqual(postStream.filteredPostsCount, 3);

    // Megatopic
    postStream.set("isMegaTopic", true);
    postStream.set("topic.highest_post_number", 4);

    assert.strictEqual(postStream.filteredPostsCount, 4);
  });

  test("lastPostId", function (assert) {
    const postStream = buildStream.call(this, 4567, [1, 3, 4]);

    assert.strictEqual(postStream.lastPostId, 4);

    postStream.setProperties({
      isMegaTopic: true,
      lastId: 2,
    });

    assert.strictEqual(postStream.lastPostId, 2);
  });

  test("progressIndexOfPostId", function (assert) {
    const postStream = buildStream.call(this, 4567, [1, 3, 4]);
    const store = getOwner(this).lookup("service:store");
    const post = store.createRecord("post", { id: 1, post_number: 5 });

    assert.strictEqual(postStream.progressIndexOfPostId(post), 1);

    postStream.set("isMegaTopic", true);

    assert.strictEqual(postStream.progressIndexOfPostId(post), 5);
  });
});