Implement the correct linking behaviour in `WikiLinkFilter`.

Original Comments
=================

- Linking behaves as per rules documented here:
  https://gitlab.com/gitlab-org/gitlab-ce/blob/16568-document-wiki-linking-behavior/doc/markdown/wiki.md
- All links (to other wiki pages) are rewritten to be at the level of
  the app root. We can't use links relative to the current
  page ('./foo', 'foo', '../foo'), because they won't work in the
  markdown preview, where the current page is suffixed with `/edit`
- Move existing `WikiLinkFilter` specs to `WikiPipeline` spec. It makes
  sense to run these tests on the combined output of the pipeline,
  rather than a single filter, since we can catch issues with
  conflicting filters.
- Add more tests to cover the new linking

@rymai's Review
===============

- Classes nested under `WikiLinkFilter` should declare `WikiLinkFilter`'s
  inherit, so nothing changes if the nested class is loaded first.
- Add a blank line after a guard clause
- Use keyword arguments for the `Rewriter` constructor
- Invert a condition - use `if` instead of `unless`
- Inline a `let` in `WikiPipeline` spec - it was only used in a single place
- Change out of date spec names
- Add a comment for every rewrite rule in `Rewriter`

1 files changed, 0 insertions, 85 deletions

diff --git a/spec/lib/banzai/filter/wiki_link_filter_spec.rb b/spec/lib/banzai/filter/wiki_link_filter_spec.rb
deleted file mode 100644
index 185abbb2108..00000000000
--- a/spec/lib/banzai/filter/wiki_link_filter_spec.rb
+++ /dev/null
@@ -1,85 +0,0 @@
-require 'spec_helper'
-
-describe Banzai::Filter::WikiLinkFilter, lib: true do
-  include FilterSpecHelper
-
-  let(:namespace) { build_stubbed(:namespace, name: "wiki_link_ns") }
-  let(:project)   { build_stubbed(:empty_project, :public, name: "wiki_link_project", namespace: namespace) }
-  let(:user) { double }
-  let(:project_wiki) { ProjectWiki.new(project, user) }
-
-  describe "links within the wiki (relative)" do
-    describe "hierarchical links to the current directory" do
-      it "doesn't rewrite non-file links" do
-        link = "<a href='./page'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('./page')
-      end
-
-      it "doesn't rewrite file links" do
-        link = "<a href='./page.md'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('./page.md')
-      end
-    end
-
-    describe "hierarchical links to the parent directory" do
-      it "doesn't rewrite non-file links" do
-        link = "<a href='../page'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('../page')
-      end
-
-      it "doesn't rewrite file links" do
-        link = "<a href='../page.md'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('../page.md')
-      end
-    end
-
-    describe "hierarchical links to a sub-directory" do
-      it "doesn't rewrite non-file links" do
-        link = "<a href='./subdirectory/page'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('./subdirectory/page')
-      end
-
-      it "doesn't rewrite file links" do
-        link = "<a href='./subdirectory/page.md'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('./subdirectory/page.md')
-      end
-    end
-
-    describe "non-hierarchical links" do
-      it 'rewrites non-file links to be at the scope of the wiki root' do
-        link = "<a href='page'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to match('/wiki_link_ns/wiki_link_project/wikis/page')
-      end
-
-      it "doesn't rewrite file links" do
-        link = "<a href='page.md'>Link to Page</a>"
-        filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-        expect(filtered_link.attribute('href').value).to eq('page.md')
-      end
-    end
-  end
-
-  describe "links outside the wiki (absolute)" do
-    it "doesn't rewrite links" do
-      link = "<a href='http://example.com/page'>Link to Page</a>"
-      filtered_link = filter(link, project_wiki: project_wiki).children[0]
-
-      expect(filtered_link.attribute('href').value).to eq('http://example.com/page')
-    end
-  end
-end