defmodule BDS.PreviewTest do
use ExUnit.Case, async: false
alias BDS.Generation
alias BDS.Media
alias BDS.Metadata
alias BDS.Posts
setup do
:ok = Ecto.Adapters.SQL.Sandbox.checkout(BDS.Repo)
temp_dir = Path.join(System.tmp_dir!(), "bds-preview-#{System.unique_integer([:positive])}")
File.mkdir_p!(temp_dir)
on_exit(fn -> File.rm_rf(temp_dir) end)
{:ok, project} = BDS.Projects.create_project(%{name: "Preview", data_path: temp_dir})
%{project: project, temp_dir: temp_dir}
end
test "start_preview binds localhost and request resolves generated routes, assets, media, and draft previews",
%{project: project, temp_dir: temp_dir} do
assert {:ok, _metadata} =
Metadata.update_project_metadata(project.id, %{
public_url: "https://example.com/blog",
main_language: "en",
blog_languages: ["en", "de"]
})
assert {:ok, _} =
Generation.write_generated_file(project.id, "index.html", "home")
assert {:ok, _} =
Generation.write_generated_file(
project.id,
"de/index.html",
"startseite"
)
assert {:ok, _} =
Generation.write_generated_file(
project.id,
"tag/elixir/index.html",
"tag archive"
)
assert {:ok, _} =
Generation.write_generated_file(
project.id,
"pagefind/pagefind-ui.js",
"console.log('pagefind')"
)
media_dir = Path.join([temp_dir, "media", "2026", "04"])
File.mkdir_p!(media_dir)
File.write!(Path.join(media_dir, "image.txt"), "media body")
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Draft Post",
content: "Draft preview body",
language: "en"
})
assert {:ok, server} = BDS.Preview.start_preview(project.id)
assert server.host == "127.0.0.1"
assert server.port == 4123
assert server.is_running == true
assert {:ok, %{body: "home", content_type: "text/html"}} =
BDS.Preview.request(project.id, "/")
assert {:ok, %{body: "startseite", content_type: "text/html"}} =
BDS.Preview.request(project.id, "/de/")
assert {:ok, %{body: "tag archive", content_type: "text/html"}} =
BDS.Preview.request(project.id, "/tag/elixir")
assert {:ok, %{body: "console.log('pagefind')", content_type: "application/javascript"}} =
BDS.Preview.request(project.id, "/pagefind/pagefind-ui.js")
assert {:ok, %{body: pico_css, content_type: "text/css"}} =
BDS.Preview.request(project.id, "/assets/pico.min.css")
assert pico_css =~ ":root"
assert {:ok, %{body: bds_css, content_type: "text/css"}} =
BDS.Preview.request(project.id, "/assets/bds.css")
assert bds_css =~ ".blog-menu"
assert {:ok, %{body: calendar_runtime, content_type: "application/javascript"}} =
BDS.Preview.request(project.id, "/assets/calendar-runtime.js")
assert calendar_runtime =~ "loadCalendarData"
assert calendar_runtime =~ "window.location.assign"
assert {:ok, %{body: tag_cloud_runtime, content_type: "application/javascript"}} =
BDS.Preview.request(project.id, "/assets/tag-cloud.js")
assert tag_cloud_runtime =~ "data-tag-cloud-words"
assert {:ok, %{body: _prev_png, content_type: "image/png"}} =
BDS.Preview.request(project.id, "/images/prev.png")
assert {:ok, %{body: _loading_gif, content_type: "image/gif"}} =
BDS.Preview.request(project.id, "/images/loading.gif")
assert {:ok, %{body: "media body", content_type: "text/plain"}} =
BDS.Preview.request(project.id, "/media/2026/04/image.txt")
assert {:ok, %{body: draft_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(project.id, "/draft/draft-post", post.id)
assert draft_html =~ "Draft preview body"
assert draft_html =~ ~s(href="/assets/pico.min.css")
assert {:error, :not_found} = BDS.Preview.request(project.id, "/media/../../secret.txt")
assert :ok = BDS.Preview.stop_preview(project.id)
end
test "draft preview renders through the published post template", %{project: project} do
assert {:ok, template} =
BDS.Templates.create_template(%{
project_id: project.id,
title: "Preview Post",
kind: :post,
content:
"{{ post.title }}
{{ post.content }}
"
})
assert {:ok, published_template} = BDS.Templates.publish_template(template.id)
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Draft Post",
content: "**Draft** preview body",
language: "en",
template_slug: published_template.slug
})
assert {:ok, _server} = BDS.Preview.start_preview(project.id)
assert {:ok, %{body: draft_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(project.id, "/draft/draft-post", post.id)
assert draft_html =~ "preview-template"
assert draft_html =~ "Draft Post"
assert draft_html =~ ~s(Draft preview body)
refute draft_html =~ "**Draft** preview body"
assert {:ok, published_post} = Posts.publish_post(post.id)
published_datetime = DateTime.from_unix!(published_post.created_at, :millisecond)
published_path =
"/#{published_datetime.year}/#{String.pad_leading(Integer.to_string(published_datetime.month), 2, "0")}/#{String.pad_leading(Integer.to_string(published_datetime.day), 2, "0")}/#{published_post.slug}"
:inets.start()
assert {:ok, server} = BDS.Preview.start_preview(project.id)
assert {:ok, {{_version, 200, _reason}, _headers, published_html}} =
:httpc.request(
:get,
{to_charlist(
"http://#{server.host}:#{server.port}#{published_path}?draft=true&post_id=#{published_post.id}"
), []},
[],
body_format: :binary
)
assert published_html =~ ~s(Draft preview body)
refute published_html =~ "**Draft** preview body"
assert :ok = BDS.Preview.stop_preview(project.id)
end
test "draft preview renders through copied starter templates with markdown and i18n", %{
project: project
} do
assert {:ok, _menu} =
BDS.Menu.update_menu(project.id, [
%{kind: :page, label: "Notes", slug: "notes"}
])
assert {:ok, _metadata} =
Metadata.update_project_metadata(project.id, %{
public_url: "https://example.com/blog",
main_language: "en",
blog_languages: ["en", "de"]
})
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Draft Post",
content: "**Draft** preview body",
language: "en"
})
assert {:ok, _server} = BDS.Preview.start_preview(project.id)
assert {:ok, %{body: draft_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(project.id, "/draft/draft-post", post.id)
assert draft_html =~ ~s(data-template="single-post")
assert draft_html =~ ~s(Draft preview body)
assert draft_html =~ "Language"
assert :ok = BDS.Preview.stop_preview(project.id)
end
test "draft preview honors the lang query parameter and falls back to the canonical draft", %{
project: project
} do
assert {:ok, _metadata} =
Metadata.update_project_metadata(project.id, %{
public_url: "https://example.com/blog",
main_language: "en",
blog_languages: ["en", "de"]
})
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Canonical Draft",
content: "Canonical body",
language: "en"
})
assert {:ok, _translation} =
Posts.upsert_post_translation(post.id, "de", %{
title: "Deutscher Entwurf",
content: "Deutscher Inhalt"
})
assert {:ok, _server} = BDS.Preview.start_preview(project.id)
assert {:ok, %{body: german_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(project.id, "/draft/canonical-draft?lang=de", post.id)
assert german_html =~ ~s( Path.join(Path.dirname(media.file_path), media.original_name)
canonical_post_href =
"/" <>
String.trim_trailing(BDS.Generation.post_output_path(published_linked_post), "index.html")
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Draft Post",
content:
[
"[Read linked post](/posts/linked-post)",
"",
"",
"",
"[[youtube id=dQw4w9WgXcQ]]"
]
|> Enum.join("\n"),
language: "en"
})
assert {:ok, server} = BDS.Preview.start_preview(project.id)
assert {:ok, %{body: draft_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(project.id, "/draft/draft-post", post.id)
assert draft_html =~ ~s(src="https://www.youtube.com/embed/dQw4w9WgXcQ?rel=0")
assert draft_html =~ ~s(href="#{canonical_post_href}")
assert draft_html =~ ~s(src="/#{media.file_path}")
assert {:ok, %{body: missing_body, content_type: "text/html"}} =
BDS.Preview.request(project.id, "/missing-page")
assert missing_body =~ ~s(data-template="not-found")
assert {:ok, {{_version, 404, _reason}, _headers, body}} =
:httpc.request(
:get,
{to_charlist("http://#{server.host}:#{server.port}/missing-page"), []},
[],
body_format: :binary
)
assert body =~ ~s(data-template="not-found")
assert :ok = BDS.Preview.stop_preview(project.id)
end
test "start_preview serves generated and draft routes over real HTTP on localhost", %{
project: project
} do
:inets.start()
assert {:ok, _metadata} =
Metadata.update_project_metadata(project.id, %{
public_url: "https://example.com/blog",
main_language: "en",
blog_languages: ["en"]
})
assert {:ok, _} =
Generation.write_generated_file(project.id, "index.html", "http home")
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "HTTP Draft",
content: "Draft over HTTP",
language: "en"
})
assert {:ok, server} = BDS.Preview.start_preview(project.id)
assert {:ok, {{_version, 200, _reason}, headers, body}} =
:httpc.request(:get, {to_charlist("http://#{server.host}:#{server.port}/"), []}, [],
body_format: :binary
)
assert body == "http home"
assert Enum.any?(headers, fn {name, value} ->
String.downcase(to_string(name)) == "content-type" and
to_string(value) =~ "text/html"
end)
assert {:ok, {{_version, 200, _reason}, _headers, draft_body}} =
:httpc.request(
:get,
{to_charlist(
"http://#{server.host}:#{server.port}/draft/http-draft?post_id=#{post.id}"
), []},
[],
body_format: :binary
)
assert draft_body =~ "Draft over HTTP"
assert :ok = BDS.Preview.stop_preview(project.id)
end
test "preview query params can override the rendered theme for generated and draft pages", %{
project: project
} do
assert {:ok, _metadata} =
Metadata.update_project_metadata(project.id, %{
public_url: "https://example.com/blog",
main_language: "en",
blog_languages: ["en"],
pico_theme: "blue"
})
assert {:ok, _result} = BDS.Generation.generate_site(project.id, [:core])
assert {:ok, post} =
Posts.create_post(%{
project_id: project.id,
title: "Theme Draft",
content: "Theme body",
language: "en"
})
assert {:ok, _server} = BDS.Preview.start_preview(project.id)
assert {:ok, %{body: generated_html, content_type: "text/html"}} =
BDS.Preview.request(project.id, "/?theme=amber&mode=dark")
assert generated_html =~ ~s(data-theme="dark")
assert generated_html =~ ~s(data-mode="dark")
assert generated_html =~ ~s(/assets/pico.amber.min.css)
assert {:ok, %{body: draft_html, content_type: "text/html"}} =
BDS.Preview.preview_draft(
project.id,
"/draft/theme-draft?theme=amber&mode=dark",
post.id
)
assert draft_html =~ ~s(data-theme="dark")
assert draft_html =~ ~s(data-mode="dark")
assert draft_html =~ ~s(/assets/pico.amber.min.css)
assert :ok = BDS.Preview.stop_preview(project.id)
end
end