From ffefa79b44e11a35621312bec5c7298956ba1d45 Mon Sep 17 00:00:00 2001
From: David Salgado <david@digitalronin.com>
Date: Wed, 5 Aug 2020 15:44:27 +0100
Subject: [PATCH] Patch the gov.uk tech-docs gems after installing

These files represent the patches described in this issue:
https://github.com/alphagov/tech-docs-gem/issues/191

They enable using (a patched version of) the gov.uk tech-docs gem to publish a
documentation site using github pages without requiring the site to be
published at the root docpath ("/") of a dedicated domain.

i.e. this enables publishing a site at:

```
https://username.github.io/my-repo
```

This is the default github pages URL for the repository "my-repo" belonging to
the github user/organisation "username".

As opposed to:

```
https://my.custom.domain/
```

Without these patches, the search function of the site will not work correctly.

The patch files in this directory are used in the Dockerfile to build the
docker image which is used in the publishing process.

This is a nasty hack, but the alternative is to maintain forks of two gems,
`govuk_tech_docs` and `middleman-search-gds`, so this seems a pragmatic
solution until the issue above is resolved in the upstream gems.
---
 Dockerfile                                 |  7 +++++
 gem-patches/README.md                      | 32 ++++++++++++++++++++++
 gem-patches/search-index-resource.rb.patch | 10 +++++++
 gem-patches/search.js.patch                | 10 +++++++
 4 files changed, 59 insertions(+)
 create mode 100644 gem-patches/README.md
 create mode 100644 gem-patches/search-index-resource.rb.patch
 create mode 100644 gem-patches/search.js.patch

diff --git a/Dockerfile b/Dockerfile
index 635efb4f..f0bdd229 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,3 +12,10 @@ WORKDIR /app
 COPY Gemfile Gemfile.lock ./
 
 RUN bundle install
+
+# patch the installed gems
+# see: https://github.com/alphagov/tech-docs-gem/issues/191
+COPY gem-patches/*.patch /tmp/
+RUN patch /usr/local/bundle/gems/middleman-search-gds-0.11.1/lib/middleman-search/search-index-resource.rb -i /tmp/search-index-resource.rb.patch
+RUN patch /usr/local/bundle/gems/govuk_tech_docs-2.0.12/lib/assets/javascripts/_modules/search.js -i /tmp/search.js.patch
+RUN mv /usr/local/bundle/gems/govuk_tech_docs-2.0.12/lib/assets/javascripts/_modules/search.js /usr/local/bundle/gems/govuk_tech_docs-2.0.12/lib/assets/javascripts/_modules/search.js.erb
diff --git a/gem-patches/README.md b/gem-patches/README.md
new file mode 100644
index 00000000..5bfae1f7
--- /dev/null
+++ b/gem-patches/README.md
@@ -0,0 +1,32 @@
+# Patches for gov.uk tech-docs gems
+
+These files represent the patches described in this issue:
+https://github.com/alphagov/tech-docs-gem/issues/191
+
+They enable using (a patched version of) the gov.uk tech-docs gem to publish a
+documentation site using github pages without requiring the site to be
+published at the root docpath ("/") of a dedicated domain.
+
+i.e. this enables publishing a site at:
+
+```
+https://username.github.io/my-repo
+```
+
+This is the default github pages URL for the repository "my-repo" belonging to
+the github user/organisation "username".
+
+As opposed to:
+
+```
+https://my.custom.domain/
+```
+
+Without these patches, the search function of the site will not work correctly.
+
+The patch files in this directory are used in the Dockerfile to build the
+docker image which is used in the publishing process.
+
+This is a nasty hack, but the alternative is to maintain forks of two gems,
+`govuk_tech_docs` and `middleman-search-gds`, so this seems a pragmatic
+solution until the issue above is resolved in the upstream gems.
diff --git a/gem-patches/search-index-resource.rb.patch b/gem-patches/search-index-resource.rb.patch
new file mode 100644
index 00000000..b289d799
--- /dev/null
+++ b/gem-patches/search-index-resource.rb.patch
@@ -0,0 +1,10 @@
++++ /usr/local/bundle/gems/middleman-search-gds-0.11.1/lib/middleman-search/search-index-resource.rb
+@@ -111,6 +111,8 @@
+           end
+         end
+
++        store.each { |id, item| item[:url].sub!(/^/, ENV["ROOT_DOCPATH"].to_s) }
++
+         # Generate JSON output
+         context = ExecJS.compile(source.join("\n"))
+         json = context.eval('lunr.middlemanSearchIndex.indexJson()')
diff --git a/gem-patches/search.js.patch b/gem-patches/search.js.patch
new file mode 100644
index 00000000..0eb3e7af
--- /dev/null
+++ b/gem-patches/search.js.patch
@@ -0,0 +1,10 @@
++++ /usr/local/bundle/gems/govuk_tech_docs-2.0.12/lib/assets/javascripts/_modules/search.js
+@@ -34,7 +34,7 @@
+     this.downloadSearchIndex = function downloadSearchIndex () {
+       updateTitle('Loading search index')
+       $.ajax({
+-        url: '/search.json',
++        url: '<%= ENV["ROOT_DOCPATH"] %>/search.json',
+         cache: true,
+         method: 'GET',
+         success: function (data) {