Add "a" watch keypress command to run --all tests (#16)

Now there are 2 ways to run the entire test suite via interactive watch
commands:

- ENTER runs all tests, excluding slow ones
- "a" runs all tests, slow tests included (equivalent to `mt --all`)

lib/mighty_test/watcher.rb

@@ -12,7 +12,7 @@ def initialize(console: Console.new, extra_args: [], file_system: FileSystem.new
       @system_proc = system_proc
     end
 
-    def run(iterations: :indefinitely) # rubocop:disable Metrics/MethodLength
+    def run(iterations: :indefinitely) # rubocop:disable Metrics/CyclomaticComplexity, Metrics/MethodLength
       start_file_system_listener
       start_keypress_listener
       puts WATCHING_FOR_CHANGES
@@ -23,6 +23,8 @@ def run(iterations: :indefinitely) # rubocop:disable Metrics/MethodLength
           run_matching_test_files(paths)
         in [:keypress, "\r" | "\n"]
           run_all_tests
+        in [:keypress, "a"]
+          run_all_tests(flags: ["--all"])
         in [:keypress, "d"]
           run_matching_test_files_from_git_diff
         in [:keypress, "q"]
@@ -41,11 +43,11 @@ def run(iterations: :indefinitely) # rubocop:disable Metrics/MethodLength
 
     attr_reader :console, :extra_args, :file_system, :file_system_listener, :keypress_listener, :system_proc
 
-    def run_all_tests
+    def run_all_tests(flags: [])
       console.clear
-      puts "Running all tests..."
+      puts flags.any? ? "Running tests with #{flags.join(' ')}..." : "Running tests..."
       puts
-      mt
+      mt(flags:)
     end
 
     def run_matching_test_files(paths)
@@ -67,8 +69,8 @@ def run_matching_test_files_from_git_diff
       puts WATCHING_FOR_CHANGES
     end
 
-    def mt(*test_paths)
-      command = ["mt", *extra_args]
+    def mt(*test_paths, flags: [])
+      command = ["mt", *extra_args, *flags]
       command.append("--", *test_paths.flatten) if test_paths.any?
 
       success = system_proc.call(*command)

test/mighty_test/watcher_test.rb

@@ -118,12 +118,27 @@ def test_watcher_runs_all_tests_when_enter_key_is_pressed
       stdout, = run_watcher(stdin: "\rq", in: fixtures_path.join("example_project"))
 
       assert_includes(stdout, <<~EXPECTED)
-        Running all tests...
+        Running tests...
 
         [SYSTEM] mt
       EXPECTED
     end
 
+    def test_watcher_runs_all_tests_with_all_flag_when_a_key_is_pressed
+      system_proc do |*args|
+        puts "[SYSTEM] #{args.join(' ')}"
+        true
+      end
+
+      stdout, = run_watcher(stdin: "aq", in: fixtures_path.join("example_project"))
+
+      assert_includes(stdout, <<~EXPECTED)
+        Running tests with --all...
+
+        [SYSTEM] mt --all
+      EXPECTED
+    end
+
     def test_watcher_runs_new_and_changed_files_according_to_git_when_d_key_is_pressed
       system_proc do |*args|
         puts "[SYSTEM] #{args.join(' ')}"