Migrate installer test to Cucumber.

test/features/installer.feature

@@ -0,0 +1,11 @@
+Feature: Install SDKMAN! if necessary
+
+    Scenario:
+        Given SDKMAN! is not installed
+        When  sdk is called and user answers "n"
+        Then  SDKMAN! is absent
+
+    Scenario:
+        Given SDKMAN! is not installed
+        When  sdk is called and user answers "y"
+        Then  SDKMAN! is present

test/features/step_definitions/installer.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'fileutils'
+
+Given(/^SDKMAN! is not installed$/) do
+  FileUtils.rm_rf("#{ENV['HOME']}/.sdkman")
+end
+
+When('sdk is called and user answers {string}') do |answer|
+  run_fish_command("echo '#{answer}' | sdk version")
+end
+
+Then(/^SDKMAN! is absent$/) do
+  expect(Dir["#{ENV['HOME']}/.sdkman/*"].count).to eq(0)
+  response = run_bash_command("sdk version")
+  expect(response[:status]).to_not eq(0)
+end
+
+Then('SDKMAN! is present') do
+  expect(Dir["#{ENV['HOME']}/.sdkman/*"].count).to be > 1
+  response = run_bash_command("sdk version")
+  expect(response[:status]).to eq(0)
+end

test/remove_sdkman.sh

@@ -1,5 +0,0 @@
-#!/usr/bin/env bash
-
-    rm -rf "${HOME}/.sdkman" \
-&&  sed -i'.bak' -E -e 's/^.*(sdkman|SDKMAN).*$//g' "${HOME}/.bashrc" \
-&&  echo 'SDKMAN! uninstalled'