Write the script for automating patch creations from posts/ subbranches

Gemfile

@@ -12,6 +12,7 @@ gem 'concurrent-ruby'
 gem 'open-uri-cached'
 gem 'rouge'
 gem 'rubocop'
+gem 'rugged'
 gem 'slim'
 gem 'tilt'
 

Gemfile.lock

@@ -73,6 +73,7 @@ GEM
       sorbet-runtime
       syntax_tree (>= 6, < 7)
     ruby-progressbar (1.13.0)
+    rugged (1.6.3)
     slim (5.1.0)
       temple (~> 0.10.0)
       tilt (>= 2.0.6, < 2.2)
@@ -100,8 +101,9 @@ DEPENDENCIES
   rouge
   rubocop
   ruby-lsp
+  rugged
   slim
   tilt
 
 BUNDLED WITH
-   2.3.7
+   2.4.6

bin/create-patches-for-content-workspace.rb

@@ -0,0 +1,100 @@
+#!/usr/bin/env nix-shell
+#! nix-shell -i ruby -p "ruby.withPackages (ps: with ps; [ rugged ])" coreutils fzf
+
+# frozen_string_literal: true
+
+# A script that recreates `git format-patch` subcommand but with a few more
+# specific use case for this project.
+require 'fileutils'
+require 'logger'
+require 'optparse'
+require 'rugged'
+
+def to_kebab_case(string)
+  string.gsub(/\s+/, '-')           # Replace all spaces with dashes.
+        .gsub(/[^a-zA-Z0-9-]/, '')  # Remove all non-alphanumerical (and dashes) characters.
+        .gsub(/-+/, '-')            # Reduce all dashes into only one.
+        .gsub(/^-|-+$/, '')         # Remove all leading and trailing dashes.
+        .downcase
+end
+
+CONTENT_DIRECTORY = 'content'
+PATCHES_SUBDIRECTORY = 'assets/patches'
+options = {
+  'current-branch': false,
+  'prefix': 'posts/',
+  'repo': '.'
+}
+
+logger = Logger.new($stdout)
+logger.level = Logger::WARN
+
+OptionParser.new do |opts|
+  opts.on('-c', '--current-branch', 'Select the current branch.') do
+    options['current-branch'] = true
+  end
+
+  opts.on('-p', '--prefix PREFIX',
+          <<~HELP
+            Sets the prefix corresponding to a subdirectory inside
+            the content directory.
+          HELP
+  ) do |prefix|
+    options['prefix'] = prefix
+  end
+
+  opts.on('--repo REPO', String, 'Select the Git repository of the workspace') do |repo|
+    options['repo'] = repo
+  end
+
+  opts.on('-v', '--[no-]verbose', 'Make the program print results') do |v|
+    options['verbose'] = v
+  end
+end.parse!
+
+logger.level = Logger::INFO if options['verbose']
+
+code_workspace = Rugged::Repository.discover(options['repo'])
+if options['current-branch']
+  selected_branch = code_workspace.branches[code_workspace.head.name].name
+  raise %(Current branch is not a '#{options['prefix']}' subbranch.) unless selected_branch.start_with? options[:prefix]
+else
+  branches = code_workspace.branches
+                           .each_name(:local)
+                           .select { |branch| branch.start_with? options[:prefix] }
+                           .sort
+
+  raise "No branches with the prefix '#{options['prefix']}'" if branches.empty?
+
+  selected_branch = `echo -e "#{branches.join '\n'}" | fzf`.strip
+end
+
+selected_branch_object = code_workspace.branches[selected_branch]
+
+repo_walker = Rugged::Walker.new(code_workspace)
+repo_walker.push(selected_branch_object.target_id)
+repo_walker.sorting(Rugged::SORT_DATE | Rugged::SORT_REVERSE)
+
+# Delete the patches directory. This makes it completely dangerous.
+patches_dir = File.expand_path("#{selected_branch}/#{PATCHES_SUBDIRECTORY}", CONTENT_DIRECTORY)
+
+FileUtils.rmtree(patches_dir, secure: true)
+logger.info "Removing '#{patches_dir}'"
+
+FileUtils.mkdir_p(patches_dir)
+logger.info "Creating directory '#{patches_dir}'"
+
+repo_walker.each_with_index do |commit, index|
+  commit_message = to_kebab_case commit.message
+  commit_index = (index + 1).to_s.rjust(4, '0')
+
+  patchfile = File.expand_path(
+    "#{commit_index}-#{commit_message}.patch",
+    patches_dir
+  )
+
+  File.open(patchfile, 'w') do |f|
+    logger.info "Creating patch file '#{patchfile}' from commit '#{commit.tree_id}'"
+    f.write commit.diff.patch
+  end
+end

gemset.nix

@@ -374,6 +374,18 @@
     targets = [];
     version = "1.13.0";
   };
+  rugged = {
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "016bawsahkhxx7p8azxirpl7y2y7i8a027pj8910gwf6ipg329in";
+      target = "ruby";
+      type = "gem";
+    };
+    targets = [];
+    version = "1.6.3";
+  };
   slim = {
     dependencies = ["temple" "tilt"];
     groups = ["default"];