# frozen_string_literal: true

require 'fast_spec_helper'

describe Gitlab::Utils::InlineHash do
  describe '.merge_keys' do
    subject { described_class.merge_keys(source) }

    let(:source) do
      {
        nested_param: {
          key: 'Value'
        },
        'root_param' => 'Root',
        'very' => {
          'deep' => {
            'nested' => {
              'param' => 'Deep nested value'
            }
          }
        }
      }
    end

    it 'transforms a nested hash into a one-level hash' do
      is_expected.to eq(
        'nested_param.key' => 'Value',
        'root_param' => 'Root',
        'very.deep.nested.param' => 'Deep nested value'
      )
    end

    it 'retains key insertion order' do
      expect(subject.keys)
        .to eq(%w(nested_param.key root_param very.deep.nested.param))
    end

    context 'with a custom connector' do
      subject { described_class.merge_keys(source, connector: '::') }

      it 'uses the connector to merge keys' do
        is_expected.to eq(
          'nested_param::key' => 'Value',
          'root_param' => 'Root',
          'very::deep::nested::param' => 'Deep nested value'
        )
      end
    end

    context 'with a starter prefix' do
      subject { described_class.merge_keys(source, prefix: 'options') }

      it 'prefixes all the keys' do
        is_expected.to eq(
          'options.nested_param.key' => 'Value',
          'options.root_param' => 'Root',
          'options.very.deep.nested.param' => 'Deep nested value'
        )
      end
    end
  end
end