Add Rake task for inserting pre-generated access token into database

This task allows inserting a token into the access tokens table without
already having an API token.

To use this, generate a UUID or other random string, and then pass the
hex encoded sha256 digest of that to the `insert` task:

```bash
TOKEN="$(ruby -e "require 'securerandom'; puts SecureRandom.uuid")"
TOKEN_DIGEST="$(ruby -e "require 'digest'; puts Digest::SHA256.hexdigest('$TOKEN')")"

bin/rails "access_tokens:insert[$USER, $TOKEN_DIGEST]"
```

Then don't forget to save the token somewhere safe!

Author: lfdebrux

lib/tasks/access_tokens.rake

@@ -0,0 +1,14 @@
+namespace :access_tokens do
+  desc "Add a pre-generated token, using the SHA256 hex digest"
+  task :insert, %i[owner token_digest] => :environment do |_, args|
+    usage_message = "usage: rails access_tokens:insert[<owner>, <token_digest>]".freeze
+    abort usage_message unless args[:owner].present? && args[:token_digest]&.match?(/^[a-f0-9]+$/)
+
+    access_token = AccessToken.create!(
+      description: "inserted with `rails access_tokens:insert`",
+      owner: args[:owner],
+      token_digest: args[:token_digest],
+    )
+    pp(access_token)
+  end
+end

spec/lib/tasks/access_tokens.rake_spec.rb

@@ -0,0 +1,27 @@
+require "rake"
+
+require "rails_helper"
+
+RSpec.describe "access_tokens.rake", type: :task do
+  before do
+    Rake.application.rake_require "tasks/access_tokens"
+    Rake::Task.define_task(:environment)
+  end
+
+  describe "access_tokens:insert" do
+    subject(:task) do
+      Rake::Task["access_tokens:insert"]
+        .tap(&:reenable)
+    end
+
+    it "inserts an access token for the user" do
+      RSpec::Matchers.define_negated_matcher :succeed, :raise_exception
+
+      expect { task.invoke("test.user", "baa") }
+        .to succeed
+        .and output(/AccessToken/).to_stdout
+        .and change { AccessToken.find_by(token_digest: "baa") }
+        .from(nil).to(an_object_having_attributes(owner: "test.user"))
+    end
+  end
+end