feat: Add action just pressed tests

Also changes the after_each method to wait for the InputSender to
release and clear all actions. There were some presses/releases
being leaked to the next test if we don't wait for an extra frame.

test/unit/test_bugs/test_i578.gd

@@ -2,14 +2,23 @@ extends GutTest
 
 class InputSingletonTracker:
 	extends Node
-	var input_frames = []
+	var pressed_frames = []
+	var just_pressed_count = 0
+	var just_released_count = 0
 
 	var _frame_counter = 0
 
 	func _process(delta):
 		_frame_counter += 1
-		if Input.is_anything_pressed():
-			input_frames.append(_frame_counter)
+
+		if(Input.is_action_just_pressed("jump")):
+			just_pressed_count += 1
+
+		if(Input.is_action_just_released("jump")):
+			just_released_count += 1
+
+		if Input.is_action_pressed("jump"):
+			pressed_frames.append(_frame_counter)
 
 class TestInputSingleton:
 	extends "res://addons/gut/test.gd"
@@ -23,6 +32,9 @@ class TestInputSingleton:
 
 	func after_each():
 		_sender.release_all()
+		# Wait for key release to be processed. Otherwise the key release is
+		# leaked to the next test and it detects an extra key release.
+		await wait_frames(1)
 		_sender.clear()
 
 	func test_raw_input_press():
@@ -32,12 +44,31 @@ class TestInputSingleton:
 		await wait_frames(10)
 		Input.action_release("jump")
 
-		assert_gt(r.input_frames.size(), 1, 'input size')
+		assert_gt(r.pressed_frames.size(), 1, 'input size')
 
 	func test_input_sender_press():
 		var r = add_child_autofree(InputSingletonTracker.new())
 
 		_sender.action_down("jump").hold_for('10f')
 		await wait_for_signal(_sender.idle, 5)
 
-		assert_gt(r.input_frames.size(), 1, 'input size')
+		print(r.pressed_frames.size())
+		assert_gt(r.pressed_frames.size(), 1, 'input size')
+
+	func test_input_sender_just_pressed():
+		var r = add_child_autofree(InputSingletonTracker.new())
+
+		_sender.action_down("jump").hold_for("20f")
+		await wait_frames(5)
+
+		assert_eq(r.just_pressed_count, 1, 'just pressed once')
+		assert_eq(r.just_released_count, 0, 'not released yet')
+
+	func test_input_sender_just_released():
+		var r = add_child_autofree(InputSingletonTracker.new())
+
+		_sender.action_down("jump").hold_for('5f')
+		await wait_for_signal(_sender.idle, 10)
+
+		assert_eq(r.just_pressed_count, 1, 'just pressed once')
+		assert_eq(r.just_released_count, 1, 'released key once')