Syntax highlighting

tests/hl/syntax_test.py

@@ -0,0 +1,147 @@
+import contextlib
+import curses
+from unittest import mock
+
+import pytest
+
+from babi.color_manager import ColorManager
+from babi.highlight import Grammar
+from babi.highlight import Grammars
+from babi.hl.syntax import Syntax
+from babi.theme import Color
+from babi.theme import Theme
+
+
+class FakeCurses:
+    def __init__(self, *, n_colors, can_change_color):
+        self._n_colors = n_colors
+        self._can_change_color = can_change_color
+        self.colors = {}
+        self.pairs = {}
+
+    def _curses__can_change_color(self):
+        return self._can_change_color
+
+    def _curses__init_color(self, n, r, g, b):
+        self.colors[n] = (r, g, b)
+
+    def _curses__init_pair(self, n, fg, bg):
+        self.pairs[n] = (fg, bg)
+
+    def _curses__color_pair(self, n):
+        assert n == 0 or n in self.pairs
+        return n << 8
+
+    @classmethod
+    @contextlib.contextmanager
+    def patch(cls, **kwargs):
+        fake = cls(**kwargs)
+        with mock.patch.object(curses, 'COLORS', fake._n_colors, create=True):
+            with mock.patch.multiple(
+                    curses,
+                    can_change_color=fake._curses__can_change_color,
+                    color_pair=fake._curses__color_pair,
+                    init_color=fake._curses__init_color,
+                    init_pair=fake._curses__init_pair,
+            ):
+                yield fake
+
+
+class FakeScreen:
+    def __init__(self):
+        self.attr = 0
+
+    def bkgd(self, c, attr):
+        assert c == ' '
+        self.attr = attr
+
+
+@pytest.fixture
+def stdscr():
+    return FakeScreen()
+
+
+THEME = Theme.from_dct({
+    'colors': {'foreground': '#cccccc', 'background': '#333333'},
+    'tokenColors': [
+        {'scope': 'string', 'settings': {'foreground': '#009900'}},
+        {'scope': 'keyword', 'settings': {'background': '#000000'}},
+        {'scope': 'keyword', 'settings': {'fontStyle': 'bold'}},
+    ],
+})
+
+
+@pytest.fixture
+def syntax():
+    return Syntax(Grammars([Grammar.blank()]), THEME, ColorManager.make())
+
+
+def test_init_screen_low_color(stdscr, syntax):
+    with FakeCurses.patch(n_colors=16, can_change_color=False) as fake_curses:
+        syntax._init_screen(stdscr)
+    assert syntax.color_manager.colors == {}
+    assert syntax.color_manager.raw_pairs == {}
+    assert fake_curses.colors == {}
+    assert fake_curses.pairs == {}
+    assert stdscr.attr == 0
+
+
+def test_init_screen_256_color(stdscr, syntax):
+    with FakeCurses.patch(n_colors=256, can_change_color=False) as fake_curses:
+        syntax._init_screen(stdscr)
+    assert syntax.color_manager.colors == {
+        Color.parse('#cccccc'): 252,
+        Color.parse('#333333'): 236,
+        Color.parse('#000000'): 16,
+        Color.parse('#009900'): 28,
+    }
+    assert syntax.color_manager.raw_pairs == {(252, 236): 1}
+    assert fake_curses.colors == {}
+    assert fake_curses.pairs == {1: (252, 236)}
+    assert stdscr.attr == 1 << 8
+
+
+def test_init_screen_true_color(stdscr, syntax):
+    with FakeCurses.patch(n_colors=256, can_change_color=True) as fake_curses:
+        syntax._init_screen(stdscr)
+    # weird colors happened with low color numbers so it counts down from max
+    assert syntax.color_manager.colors == {
+        Color.parse('#000000'): 255,
+        Color.parse('#009900'): 254,
+        Color.parse('#333333'): 253,
+        Color.parse('#cccccc'): 252,
+    }
+    assert syntax.color_manager.raw_pairs == {(252, 253): 1}
+    assert fake_curses.colors == {
+        255: (0, 0, 0),
+        254: (0, 600, 0),
+        253: (200, 200, 200),
+        252: (800, 800, 800),
+    }
+    assert fake_curses.pairs == {1: (252, 253)}
+    assert stdscr.attr == 1 << 8
+
+
+def test_lazily_instantiated_pairs(stdscr, syntax):
+    # pairs are assigned lazily to avoid hard upper limit (256) on pairs
+    with FakeCurses.patch(n_colors=256, can_change_color=False) as fake_curses:
+        syntax._init_screen(stdscr)
+
+        assert len(syntax.color_manager.raw_pairs) == 1
+        assert len(fake_curses.pairs) == 1
+
+        style = THEME.select(('string.python',))
+        attr = syntax.get_blank_file_highlighter().attr(style)
+        assert attr == 2 << 8
+
+        assert len(syntax.color_manager.raw_pairs) == 2
+        assert len(fake_curses.pairs) == 2
+
+
+def test_style_attributes_applied(stdscr, syntax):
+    with FakeCurses.patch(n_colors=256, can_change_color=False):
+        syntax._init_screen(stdscr)
+
+        style = THEME.select(('keyword.python',))
+        attr = syntax.get_blank_file_highlighter().attr(style)
+        assert attr == 2 << 8 | curses.A_BOLD