(maint) Add a spec case for the provision::abs task

The abs.rb is refactored into a class that is executed only if the task
file is the executing program. This allows the spec to load the task and
manipulate the class while mocking externals. The webmock gem is used to
provide HTTP::Net mocking.

The spec is not exhaustive, but hopefully covers enough to validate that
the refactor didn't break the task, and that the bug I added in #182 is
patched.

It could be expanded, and could serve as a template for adding specs
for other tasks in the module.

It does look to expose an edge case bug of calling the provision task
with an inventory directory specified that contains a pre-existing
inventory file.

Gemfile

@@ -10,6 +10,7 @@ group :development do
   gem "puppet-module-win-default-r#{minor_version}",   require: false, platforms: %i[mswin mingw x64_mingw]
   gem "puppet-module-win-dev-r#{minor_version}",       require: false, platforms: %i[mswin mingw x64_mingw]
   gem 'github_changelog_generator',                    require: false if Gem::Version.new(RUBY_VERSION.dup) >= Gem::Version.new('2.5.0')
+  gem 'webmock'
 end
 
 # Evaluate Gemfile.local and ~/.gemfile if they exist

spec/tasks/abs_spec.rb

@@ -0,0 +1,152 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'webmock/rspec'
+require_relative '../../tasks/abs.rb'
+require 'yaml'
+
+RSpec.shared_context('with_tmpdir') do
+  let(:tmpdir) { @tmpdir } # rubocop:disable RSpec/InstanceVariable
+
+  around(:each) do |example|
+    Dir.mktmpdir('rspec-provision_test') do |t|
+      @tmpdir = t
+      example.run
+    end
+  end
+end
+
+describe 'provision::abs' do
+  let(:abs) { ABSProvision.new }
+  let(:inventory_dir) { "#{tmpdir}/spec/fixtures" }
+  let(:inventory_file) { "#{inventory_dir}/litmus_inventory.yaml" }
+  let(:empty_inventory_yaml) do
+    <<~YAML
+      ---
+      version: 2
+      groups:
+      - name: docker_nodes
+        targets: []
+      - name: ssh_nodes
+        targets: []
+      - name: winrm_nodes
+        targets: []
+    YAML
+  end
+
+  include_context('with_tmpdir')
+
+  before(:each) do
+    FileUtils.mkdir_p(inventory_dir)
+  end
+
+  context '.run' do
+    it 'handles JSON parameters from stdin' do
+      json_input = '{"action":"foo","platform":"bar"}'
+      expect($stdin).to receive(:read).and_return(json_input)
+
+      expect { ABSProvision.run }.to(
+        raise_error(SystemExit) { |e|
+          expect(e.status).to eq(0)
+        }.and(
+          output("null\n").to_stdout,
+        ),
+      )
+    end
+
+    it 'raises an error when platform not given for provision' do
+      expect($stdin).to receive(:read).and_return('{"action":"provision"}')
+
+      expect { ABSProvision.run }.to raise_error(RuntimeError, %r{specify a platform when provisioning})
+    end
+
+    it 'raises an error when node_name not given for tear_down'
+    it 'raises an error if both node_name and platform are given'
+  end
+
+  context 'provision' do
+    let(:params) do
+      {
+        action: 'provision',
+        platform: 'redhat-8-x86_64',
+        inventory: tmpdir,
+      }
+    end
+    let(:response_body) do
+      [
+        {
+          'type'     => 'redhat-8-x86_64',
+          'hostname' => 'foo-bar.test',
+        },
+      ]
+    end
+
+    it 'provisions the platform' do
+      stub_request(:post, 'https://abs-prod.k8s.infracore.puppet.net/api/v2/request')
+        .to_return({ status: 202 }, { status: 200, body: response_body.to_json })
+
+      expect(abs.task(params)).to eq({ status: 'ok', nodes: 1 })
+
+      updated_inventory = YAML.load_file(inventory_file)
+      ssh_targets = updated_inventory['groups'].find { |g| g['name'] == 'ssh_nodes' }['targets']
+      expect(ssh_targets.size).to eq(1)
+      expect(ssh_targets.first.dig('facts', 'platform')).to eq('redhat-8-x86_64')
+    end
+
+    it 'provision with an existing inventory file' do
+      pending(<<~EOS)
+        XXX: (#187) It looks like there's an error hidden here in the way
+        lib/task_helper.rb get_inventory_hash() attempts to call
+        PuppetLitmus::InventoryManipulation.inventory_hash_from_inventory_file()
+        as though it were a class method.
+      EOS
+
+      stub_request(:post, 'https://abs-prod.k8s.infracore.puppet.net/api/v2/request')
+        .to_return({ status: 202 }, { status: 200, body: response_body.to_json })
+
+      File.write(inventory_file, empty_inventory_yaml)
+
+      expect(abs.task(params)).to eq({ status: 'ok', nodes: 1 })
+    end
+
+    it 'raises an error if abs returns error response'
+  end
+
+  context 'teardown' do
+    let(:params) do
+      {
+        action: 'tear_down',
+        node_name: 'foo-bar.test',
+        inventory: tmpdir,
+      }
+    end
+    let(:inventory_yaml) do
+      empty = YAML.safe_load(empty_inventory_yaml)
+      groups = empty['groups']
+      ssh_nodes = groups.find { |g| g['name'] == 'ssh_nodes' }
+      ssh_nodes['targets'] << {
+        'uri' => 'foo-bar.test',
+        'facts' => {
+          'platform' => 'redhat-8-x86_64',
+          'job_id' => 'a-job-id',
+        }
+      }
+      empty.to_yaml
+    end
+
+    before(:each) do
+      File.write(inventory_file, inventory_yaml)
+    end
+
+    it 'tear_down a node' do
+      expect(abs).to receive(:token_from_fogfile).and_return('fog-token')
+      stub_request(:post, 'https://abs-prod.k8s.infracore.puppet.net/api/v2/return')
+        .to_return(status: 200)
+
+      expect(abs.task(params)).to eq({ status: 'ok', removed: [ 'foo-bar.test' ] })
+      expect(YAML.load_file(inventory_file)).to eq(YAML.safe_load(empty_inventory_yaml))
+    end
+
+    it 'raises an error if abs returns error response'
+  end
+end