Fix bugs in Color.from_cocoa and from_legacy_trigger (#598)

* Fix undefined MissingDependency, int(str) typo, and tuple annotation in color.py

- Define MissingDependency as a subclass of ImportError
- Fix int(str) to int(s) in from_legacy_trigger
- Fix return type annotation from ('Color', 'Color') to typing.Tuple

* Add tests for MissingDependency exception

Author: mkusaka

api/library/python/iterm2/iterm2/color.py

@@ -11,6 +11,11 @@
 import typing
 
 
+class MissingDependency(ImportError):
+    """Raised when an optional dependency (e.g. pyobjc) is not installed."""
+    pass
+
+
 class ColorSpace(enum.Enum):
     """Describes the color space of a :class:`Color`."""
     SRGB = "sRGB"  #: SRGB color space
@@ -87,8 +92,8 @@ def from_cocoa(b: str) -> typing.Optional['Color']:
              round(nscolor.alphaComponent() * 255))
 
     @staticmethod
-    def from_legacy_trigger(s: str) -> ('Color', 'Color'):
-        i = int(str)
+    def from_legacy_trigger(s: str) -> typing.Tuple[typing.Optional['Color'], typing.Optional['Color']]:
+        i = int(s)
         if not gAppKitAvailable:
             raise MissingDependency("Colors cannot be parsed unless the pyobjc package is installed")
 

api/library/python/iterm2/tests/test_color.py

@@ -1,6 +1,6 @@
 """Tests for iterm2.color module."""
 import pytest
-from iterm2.color import Color, ColorSpace
+from iterm2.color import Color, ColorSpace, MissingDependency
 
 
 class TestColor:
@@ -149,6 +149,24 @@ def test_hex_white(self):
         assert color.hex == "#ffffff"
 
 
+class TestMissingDependency:
+    """Tests for MissingDependency exception."""
+
+    def test_is_subclass_of_import_error(self):
+        """Test that MissingDependency is a subclass of ImportError."""
+        assert issubclass(MissingDependency, ImportError)
+
+    def test_from_cocoa_without_pyobjc(self):
+        """Test that from_cocoa raises MissingDependency without pyobjc."""
+        with pytest.raises(MissingDependency):
+            Color.from_cocoa("dGVzdA==")
+
+    def test_from_legacy_trigger_without_pyobjc(self):
+        """Test that from_legacy_trigger raises MissingDependency without pyobjc."""
+        with pytest.raises(MissingDependency):
+            Color.from_legacy_trigger("0")
+
+
 class TestColorRepr:
     """Tests for Color.__repr__() method."""