configure test

Author: tompng

Gemfile

@@ -6,3 +6,5 @@ source "https://rubygems.org"
 gemspec
 
 gem "rake", "~> 13.0"
+gem "test-unit"
+gem "test-unit-ruby-core"

Rakefile

@@ -1,4 +1,37 @@
 # frozen_string_literal: true
 
 require "bundler/gem_tasks"
-task default: %i[]
+require "rake/testtask"
+
+Rake::TestTask.new(:test) do |t|
+  t.libs << "test"
+  t.libs << "lib"
+  t.test_files = FileList["test/repl_completion/test_*.rb"]
+end
+
+# To make sure they have been correctly setup for Ruby CI.
+desc "Run each repl_completion test file in isolation."
+task :test_in_isolation do
+  failed = false
+
+  FileList["test/repl_completion/test_*.rb"].each do |test_file|
+    ENV["TEST"] = test_file
+    begin
+      Rake::Task["test"].execute
+    rescue => e
+      failed = true
+      msg = "Test '#{test_file}' failed when being executed in isolation. Please make sure 'rake test TEST=#{test_file}' passes."
+      separation_line = '=' * msg.length
+
+      puts <<~MSG
+        #{separation_line}
+        #{msg}
+        #{separation_line}
+      MSG
+    end
+  end
+
+  fail "Some tests failed when being executed in isolation" if failed
+end
+
+task default: %i[test test_in_isolation]