Refactor PTY

PTY now provides a public interface to an underlying instance of
PTYNative. The PTYNative class can be extended as appropriate for
each platform and the platform-specific implementation will be
selected by PTY at runtime.

test/unit/pty.test.gd

@@ -0,0 +1,102 @@
+extends "res://addons/gut/test.gd"
+
+
+class MockPTY:
+	extends "res://addons/godot_xterm/nodes/pty/pty_native.gd"
+
+	func write(data):
+		emit_signal("data_received", data)
+
+
+class BaseTest:
+	extends "res://addons/gut/test.gd"
+	const PTY := preload("res://addons/godot_xterm/pty.gd")
+
+	var pty: PTY
+	var mock_pty_native: MockPTY
+
+	func before_each():
+		pty = add_child_autofree(PTY.new())
+		mock_pty_native = autofree(MockPTY.new())
+		pty._pty_native = mock_pty_native
+		watch_signals(mock_pty_native)
+
+
+class TestPTYInterfaceGodotXterm2_0_0:
+	extends BaseTest
+	# Test that PTY class conforms to the GodotXterm 2.0.0 specification published at:
+	# https://github.com/lihop/godot-xterm/wiki/PTY
+
+	func test_has_property_terminal_path():
+		assert_true("terminal_path" in pty, "Expected pty to have property terminal_path")
+		assert_typeof(pty.terminal_path, typeof(NodePath()))
+
+	func test_has_property_cols():
+		assert_true("cols" in pty, "Expected pty to have property cols.")
+		assert_typeof(pty.cols, typeof(0))
+
+	func test_has_property_rows():
+		assert_true("rows" in pty, "Expected pty to have property rows.")
+		assert_typeof(pty.rows, typeof(0))
+
+	func test_has_property_env():
+		assert_true("env" in pty, "Expected pty to have property env.")
+		assert_typeof(pty.env, typeof(Dictionary()))
+
+	func test_has_property_use_os_env():
+		assert_true("use_os_env" in pty, "Expected pty to have property use_os_env.")
+		assert_typeof(pty.use_os_env, typeof(false))
+
+	func test_has_method_fork():
+		assert_has_method(pty, "fork")
+
+	func test_has_method_kill():
+		assert_has_method(pty, "kill")
+
+	func test_has_method_open():
+		assert_has_method(pty, "open")
+
+	func test_has_method_resize():
+		assert_has_method(pty, "resize")
+
+	func test_has_method_resizev():
+		assert_has_method(pty, "resizev")
+
+	func test_has_method_write():
+		assert_has_method(pty, "write")
+
+	func test_has_signal_data_received():
+		assert_has_signal(pty, "data_received")
+
+	func test_has_signal_exited():
+		assert_has_signal(pty, "exited")
+
+	func test_has_enum_Signal():
+		assert_true("Signal" in pty, "Expected pty to have enum Signal.")
+		assert_typeof(pty.Signal, typeof(Dictionary()))
+		var signals = {
+			SIGHUP = 1,
+			SIGINT = 2,
+			SIGQUIT = 3,
+			SIGILL = 4,
+			SIGTRAP = 5,
+			SIGABRT = 6,
+			SIGFPE = 8,
+			SIGKILL = 9,
+			SIGSEGV = 11,
+			SIGPIPE = 13,
+			SIGALRM = 14,
+			SIGTERM = 15,
+		}
+		assert_gt(
+			pty.Signal.size(),
+			signals.size() - 1,
+			"Expected Signal enum to have at least %d members." % signals.size()
+		)
+		for signame in signals.keys():
+			assert_has(pty.Signal, signame, "Expected Signal enum to have member %s." % signame)
+			assert_eq(
+				pty.Signal[signame],
+				signals[signame],
+				"Expected Signal enum member %s to have value %d." % [signame, signals[signame]]
+			)