Add Unit Tests for Portrait Animations.

Tests/Unit/guess_special_resource_test.gd

@@ -0,0 +1,40 @@
+extends GdUnitTestSuite
+
+## Check if transition animations can be accessed with "in", "out, "in out"
+## as space-delimited prefix.
+func test_fade_in_animation_paths() -> void:
+	const TYPE := "PortraitAnimation"
+	var fade_in_1 := DialogicResourceUtil.guess_special_resource(TYPE, "fade in", "")
+	var fade_in_2 := DialogicResourceUtil.guess_special_resource(TYPE, "fade in out", "")
+	var fade_in_3 := DialogicResourceUtil.guess_special_resource(TYPE, "fade out", "")
+
+	var is_any_fade_in_empty := fade_in_1.is_empty() or fade_in_2.is_empty() or fade_in_3.is_empty()
+	assert(is_any_fade_in_empty == false, "Fade In/Out animations are empty.")
+
+	var are_all_fade_in_equal := fade_in_1 == fade_in_2 and fade_in_2 == fade_in_3
+	assert(are_all_fade_in_equal == true, "Fade In/Out animations returned different paths.")
+
+
+## Test if invalid animation paths will return empty strings.
+func test_invalid_animation_path() -> void:
+	const TYPE := "PortraitAnimation"
+	var invalid_animation_1 := DialogicResourceUtil.guess_special_resource(TYPE, "fade i", "")
+	assert(invalid_animation_1.is_empty() == true, "Invalid animation 1's path is not empty.")
+
+
+	var invalid_animation_2 := DialogicResourceUtil.guess_special_resource(TYPE, "fade", "")
+	assert(invalid_animation_2.is_empty() == true, "Invalid animation 2's path is not empty.")
+
+
+## Test if invalid types will return empty strings.
+func test_invalid_type_path() -> void:
+	const INVALID_TYPE := "Portait Animation"
+	var invalid_animation := DialogicResourceUtil.guess_special_resource(INVALID_TYPE, "fade in", "")
+	assert(invalid_animation.is_empty() == true, "Invalid animation 1's path is not empty.")
+
+	const VALID_TYPE := "PortraitAnimation"
+	var valid_animation_path := DialogicResourceUtil.guess_special_resource(VALID_TYPE, "fade in", "")
+	assert(valid_animation_path.is_empty() == false, "Valids animation's path is empty.")
+
+	assert(not invalid_animation == valid_animation_path, "Valid and invalid animation paths are equal.")
+