Handle branch deletion

Author: visortelle

.github/workflows/branch-deleted.yml

@@ -0,0 +1,16 @@
+name: Branch Deleted
+
+on: delete
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+          ref: gh-pages
+
+      - name: Remove stale deployments
+        run: ./.github/workflows/deployment/delete.sh $GITHUB_REF_NAME

.github/workflows/main.yml renamed to .github/workflows/build.yml

@@ -1,12 +1,7 @@
-# This is a basic workflow to help you get started with Actions
+name: Build
 
-name: CI
-
-# Controls when the workflow will run
 on:
-  # Triggers the workflow on push or pull request events but only for the hakyll branch
   push:
-    # branches:
     branches-ignore:
       - gh-pages
   pull_request:
@@ -18,17 +13,14 @@ on:
 
 # A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
-  # This workflow contains a single job called "build"
   build:
-    # The type of runner that the job will run on
     runs-on: ubuntu-latest
 
     strategy:
       matrix:
         stack: ["2.7.3"]
         ghc: ["8.10.7"]
 
-    # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v2
@@ -56,4 +48,4 @@ jobs:
           stack exec --system-ghc site rebuild
 
       - name: Deploy site
-        run: ./.github/workflows/deploy.sh
+        run: ./.github/workflows/deployment/deploy.sh

.github/workflows/deployment/commons.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+export repo_root_dir=$(git rev-parse --show-toplevel)
+export site_src="${repo_root_dir}/_site"
+export gh_pages_dir="${repo_root_dir}/docs"
+export deployments_dir="${gh_pages_dir}/branches"
+
+# Site built from the main branch will be available at 'https://<domain_name>/'.
+# Sites built from other branchs will be available at 'https://<domain_name>/branches/<branch_name>'.
+export main_git_branch="hakyll"
+
+# replace "/", "#", etc with "-".
+slugify() {
+  echo "$1" | iconv -c -t ascii//TRANSLIT | sed -E 's/[~^]+/-/g' | sed -E 's/[^a-zA-Z0-9]+/-/g' | sed -E 's/^-+|-+$/-/g' | tr A-Z a-z
+}
+export -f slugify

.github/workflows/deployment/delete.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# Remove deployment by specified git branch name.
+# Script assumes that you are on gh-pages branch.
+
+set -eo pipefail
+
+script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+source $script_dir/commons.sh
+
+branch_slug=$($script_dir/slugify.sh $1)
+
+rm -rf "$deployments_dir/$branch_slug"

.github/workflows/deploy.sh renamed to .github/workflows/deployment/deploy.sh

@@ -4,18 +4,11 @@
 
 set -eo pipefail
 
-git_repo_root=$(git rev-parse --show-toplevel)
-site_src="${git_repo_root}/_site"
-gh_pages_root="${git_repo_root}/docs"
+script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+source $script_dir/commons.sh
 
-# Site built from the main branch will be available at 'https://<domain_name>/'.
-# Sites built from other branchs will be available at 'https://<domain_name>/branches/<branch_name>'.
-main_git_branch="hakyll"
-
-# replace "/", "#", etc with "-".
-slugify() {
-  echo "$1" | iconv -c -t ascii//TRANSLIT | sed -E 's/[~^]+/-/g' | sed -E 's/[^a-zA-Z0-9]+/-/g' | sed -E 's/^-+|-+$/-/g' | tr A-Z a-z
-}
+git config user.name github-actions
+git config user.email github-actions@github.com
 
 deploy() {
   if [[ ! -z "$GITHUB_REF_NAME" ]]; then
@@ -26,27 +19,25 @@ deploy() {
   fi
   echo "Current git branch is '${git_branch}'."
 
-  git config user.name github-actions
-  git config user.email github-actions@github.com
-
   git checkout gh-pages
   git pull origin gh-pages
 
   if [ "$git_branch" == "$main_git_branch" ]; then
-    site_dest="${gh_pages_root}"
+    site_dest="${gh_pages_dir}"
 
     # Create temporary backup for other branches content.
-    mv "${gh_pages_root}/branches" .
+    mv "${deployments_dir}" .
 
     # Replace site files.
     rm -rf "${site_dest}"
     mkdir -p "${site_dest}"
     cp -a -v ${site_src}/* ${site_dest}/
 
     # Restore temporary backup for other branches content.
-    mv ./branches "${gh_pages_root}/"
+    mv ./branches "${gh_pages_dir}/"
   else
-    site_dest="${gh_pages_root}/branches/$(slugify ${git_branch})"
+    branch_slug=$(slugify $git_branch)
+    site_dest="${gh_pages_dir}/branches/${branch_slug}"
 
     # Replace site files.
     rm -rf "${site_dest}"
@@ -86,10 +77,10 @@ update_deployments_list() {
   main_deployment_url="https://${github_repo_owner}.github.io/${github_repo_name}/"
   echo "| [${main_git_branch}](https://github.com/${github_repo_owner}/${github_repo_name}/tree/${branch}) | [Open](${main_deployment_url}) |" >>$deployments_list
 
-  remote_branches=$( git ls-remote --heads origin | sed 's?.*refs/heads/??' | grep -v "gh-pages" | grep -v "${main_git_branch}")
+  remote_branches=$(git ls-remote --heads origin | sed 's?.*refs/heads/??' | grep -v "gh-pages" | grep -v "${main_git_branch}")
   echo "$remote_branches" | while IFS= read -r branch; do
-    safe_branch=$(slugify $branch)
-    deployment_url="https://${github_repo_owner}.github.io/${github_repo_name}/branches/${safe_branch}"
+    branch_slug=$(slugify $branch)
+    deployment_url="https://${github_repo_owner}.github.io/${github_repo_name}/branches/${branch_slug}"
     echo "| [${branch}](https://github.com/${github_repo_owner}/${github_repo_name}/tree/${branch}) | [Open](${deployment_url}) |" >>$deployments_list
   done