commands: add basic command parser infrastructure

3 files changed, 93 insertions, 0 deletions

diff --git a/Tests/ComponentTests/ParserTests/CommandParserTestBase.gd b/Tests/ComponentTests/ParserTests/CommandParserTestBase.gd
new file mode 100644
index 0000000..6e452cb
--- /dev/null
+++ b/Tests/ComponentTests/ParserTests/CommandParserTestBase.gd
@@ -0,0 +1,29 @@
+extends GutTest
+
+class_name CommandParserTestBase
+
+const CommandParser = preload("res://Scripts/CommandParser.cs")
+
+var _instance: CommandParser
+
+func _to_bits(number: int, bits: int) -> Array:
+	var result = []
+	for bit in bits:
+		result.append(number & 1)
+		number = number >> 1
+	return result
+
+func before_each():
+	_instance = autofree(CommandParser.new())
+
+func generate_capitalization_permutations(text: String) -> Array:
+	var result = []
+
+	for permutation in pow(2, text.length()):
+		var mask = _to_bits(permutation, text.length())
+		var copy = String(text)
+		for index in len(mask):
+			if mask[index] == 1:
+				copy[index] = copy[index].to_upper()
+		result.append(copy)
+	return result;
diff --git a/Tests/ComponentTests/ParserTests/test_CommandParser.gd b/Tests/ComponentTests/ParserTests/test_CommandParser.gd
new file mode 100644
index 0000000..bdb14a6
--- /dev/null
+++ b/Tests/ComponentTests/ParserTests/test_CommandParser.gd
@@ -0,0 +1,9 @@
+extends CommandParserTestBase
+
+const Command = preload("res://Scripts/Command.cs")
+
+func parse(input: String) -> Command:
+	return autofree(_instance.TryParse(input))
+
+func test_parsing_the_empty_string_returns_null():
+	assert_null(parse(''))
diff --git a/Tests/ComponentTests/ParserTests/test_LookCommand.gd b/Tests/ComponentTests/ParserTests/test_LookCommand.gd
new file mode 100644
index 0000000..32268b0
--- /dev/null
+++ b/Tests/ComponentTests/ParserTests/test_LookCommand.gd
@@ -0,0 +1,55 @@
+extends CommandParserTestBase
+
+const LookCommand = preload("res://Scripts/Commands/LookCommand.cs")
+
+var _around_permutations = generate_capitalization_permutations('around')
+var _at_permutations = generate_capitalization_permutations('at')
+var _look_permutations = generate_capitalization_permutations('look')
+
+func parse(input: String) -> LookCommand:
+	return autofree(_instance.TryParse(input))
+
+func test_parsing_look_command_without_an_argument_returns_non_null():
+	assert_not_null(parse('look'))
+
+func test_parsing_look_command_is_case_insensitive(permutation=use_parameters(_look_permutations)):
+	assert_not_null(parse(permutation))
+
+func test_parsing_look_command_without_an_argument_returns_look_command_with_an_emtpy_target():
+	assert_eq('', parse('look').Target)
+
+func test_parsing_look_at_command_is_case_insensitive(permutation=use_parameters(_at_permutations)):
+	assert_not_null(parse('look ' + permutation))
+
+func test_parsing_look_at_command_without_further_arguments_returns_look_command_with_an_emtpy_target():
+	assert_eq('', parse('look at').Target)
+
+func test_parsing_look_at_command_without_further_arguments_returns_look_command_with_non_null_modifier():
+	assert_not_null(parse('look at').Modifier)
+
+func test_parsing_look_at_command_without_further_arguments_returns_look_command_with_at_modifier():
+	assert_eq('At', parse('look at').ModifierAsString)
+
+func test_parsing_look_at_command_with_more_arguments_returns_look_command_with_non_empty_target():
+	assert_ne('', parse('look at door on the left').Target)
+
+func test_parsing_look_at_command_with_an_additional_argument_returns_look_command_with_the_additional_argument_as_the_target():
+	assert_eq('window', parse('look at window').Target)
+
+func test_parsing_look_at_command_with_multiple_additional_arguments_returns_look_command_with_the_additional_arguments_as_the_target():
+	assert_eq('table near the door', parse('look at table near the door').Target)
+
+func test_parsing_look_around_command_is_case_insensitive(permutation=use_parameters(_around_permutations)):
+	assert_not_null(parse('look ' + permutation))
+
+func test_parsing_look_around_command_without_further_arguments_returns_look_command_with_an_empty_target():
+	assert_eq('', parse('look around').Target)
+
+func test_parsing_look_around_command_without_further_arguments_returns_look_command_with_non_null_modifier():
+	assert_not_null(parse('look around').Modifier)
+
+func test_parsing_look_around_command_without_further_arguments_returns_look_command_with_around_modifier():
+	assert_eq('Around', parse('look around').ModifierAsString)
+
+func test_parsing_look_around_command_ignores_all_additional_arguments():
+	assert_eq('', parse('look around the room').Target)