Merge pull request #51005 from zzak/test-runner-did-you-mean

Rails test command suggests similar test files when the given file is not found

railties/lib/rails/commands/test/test_command.rb

@@ -31,6 +31,8 @@ module Rails
         Rails::TestUnit::Runner.parse_options(args)
         run_prepare_task if self.args.none?(EXACT_TEST_ARGUMENT_PATTERN)
         Rails::TestUnit::Runner.run(args)
+      rescue Rails::TestUnit::InvalidTestError => error
+        say error.message
       end
 
       # Define Thor tasks to avoid going through Rake and booting twice when using bin/rails test:*

railties/lib/rails/test_unit/runner.rb

@@ -9,6 +9,15 @@ require "rails/test_unit/test_parser"
 
 module Rails
   module TestUnit
+    class InvalidTestError < StandardError
+      def initialize(path, suggestion)
+        super(<<~MESSAGE.squish)
+          Could not load test file: #{path}.
+          #{suggestion}
+        MESSAGE
+      end
+    end
+
     class Runner
       TEST_FOLDERS = [:models, :helpers, :channels, :controllers, :mailers, :integration, :jobs, :mailboxes]
       PATH_ARGUMENT_PATTERN = %r"^(?!/.+/$)[.\w]*[/\\]"
@@ -48,7 +57,17 @@ module Rails
         def load_tests(argv)
           patterns = extract_filters(argv)
           tests = list_tests(patterns)
-          tests.to_a.each { |path| require File.expand_path(path) }
+          tests.to_a.each do |path|
+            require File.expand_path(path)
+          rescue LoadError => exception
+            all_tests = list_tests([default_test_glob])
+            corrections = DidYouMean::SpellChecker.new(dictionary: all_tests).correct(path)
+
+            if corrections.empty?
+              raise exception
+            end
+            raise InvalidTestError.new(path, DidYouMean::Formatter.message_for(corrections))
+          end
         end
 
         def compose_filter(runnable, filter)

railties/test/application/test_runner_test.rb

@@ -964,6 +964,14 @@ module ApplicationTests
       assert_match(%r{cannot load such file.+test/not_exists\.rb}, error)
     end
 
+    def test_did_you_mean_when_specified_file_name_is_close
+      create_test_file :models, "account"
+      output = run_test_command("test/models/accnt.rb")
+
+      assert_match(%r{Could not load test file.+test/models/accnt\.rb}, output)
+      assert_match(%r{Did you mean?.+test/models/account_test\.rb}, output)
+    end
+
     def test_pass_TEST_env_on_rake_test
       create_test_file :models, "account"
       create_test_file :models, "post", pass: false