replace casting with __render__ protocol + tests

darwcss/darwcss.py

@@ -5,21 +5,33 @@ from inspect import currentframe
 from textwrap import indent
 from colorsys import rgb_to_hls, rgb_to_hsv, rgb_to_yiq
 
-class AutoAddSelectorNotFoundInScope(Exception):
-    pass
 
+def render(obj):
+    if hasattr(obj, '__render__'):
+        return obj.__render__()
+    elif obj is None: 
+        return "none" # None requires specific serialization.
+    else:
+        return f"{obj}" # Serialize to string
+        
 @dataclass
 class ColorValue:
     red: int
     green: int
     blue: int
     typ: str = "rgb"
-
+    
+    def __render__(self):
+        return f"rgb({self.red}, {self.green}, {self.blue})" if self.typ == "rgb" else f"#{self.red}{self.green}{self.blue}"
+        
 @dataclass
 class NumericValue:
     value: Union[float, int]
     unit: str
-    
+
+    def __render__(self):
+        return f"{self.value}{self.unit}"
+        
 @dataclass
 class Style:
     name: str
@@ -27,13 +39,17 @@ class Style:
     important: bool = False
 
     def __post_init__(self):
-        self.value = CSS.cast(self.value)
-        f = currentframe().f_back.f_back.f_globals
-        if f.get("DARWCSS_AUTO", False):
+        self.value = render(self.value)
+        f = currentframe().f_back.f_back
+        l, g = f.f_locals, f.f_globals
+        if l.get("DARWCSS_AUTO", g.get("DARWCSS_AUTO", False)):
             try:
-                f[f.get("DARWCSS_SELECTOR", 'selector')].append(self)
+                selector_name = l.get("DARWCSS_SELECTOR", g.get("DARWCSS_SELECTOR", "selector"))
+                selector = l[selector_name]
             except KeyError as exc:
-                raise AutoAddSelectorNotFoundInScope from exc
+                raise NameError(f"Selector can not found in local namespace.") from exc
+            else:
+                selector.append(self)
 
 @dataclass
 class Selector:
@@ -62,28 +78,5 @@ class CSS:
             yield selector.styles
         finally:
             self.selectors.append(selector)
-
-    @staticmethod
-    def cast(value):
-        if isinstance(value, str):
-            return value
-        
-        elif isinstance(value, float) or isinstance(value, int):
-            return f"{value}" # casts value to string with fstring's performance instead of str() call
-        
-        elif isinstance(value, NumericValue):
-            return f"{value.value}{value.unit}"
-            
-        elif isinstance(value, ColorValue):
-            if value.typ == "rgb":
-                return f"rgb({value.red}, {value.green}, {value.blue})"
-            elif value.typ == "hsl":
-                return f"hsl({value.red}, {value.green}%, {value.blue}%)"
-            elif value.typ == "hex":
-                return f"#{value.red}{value.green}{value.blue}"
-            else:
-                return "black"
-        else:
-            return "none"
             
     __call__ = render

tests/test_color.py

+import unittest
+from darwcss.darwcss import ColorValue, render
+
+class TestColorValue(unittest.TestCase):
+    def test_output_rgb(self):
+        red = ColorValue(255, 0, 0)
+        blue = ColorValue(0, 0, 255, "rgb")
+        
+        self.assertEqual(render(red), "rgb(255, 0, 0)")
+        self.assertEqual(render(blue), "rgb(0, 0, 255)")
+        
+    def test_output_hex(self):
+        purple = ColorValue("fa", "ff", "ca", "hex")
+        self.assertEqual(render(purple), "#faffca")
+        
+if __name__ == '__main__':
+    unittest.main()

tests/test_css.py

+import unittest
+from darwcss.darwcss import CSS, Style
+
+class TestCSS(unittest.TestCase):
+    rendered_css = '.home{\n    a: b;\n    c: d;\n}\n'
+    
+    def test_css_with(self):
+        css = CSS()
+        with css.selector('.home') as selector:
+            selector.append(Style('a', 'b'))
+            selector.append(Style('c', 'd'))
+        
+        self.assertEqual(css.render(), self.rendered_css)
+    
+    def test_css_auto_add(self):
+        css = CSS()
+        DARWCSS_AUTO = True
+        
+        with css.selector('.home') as selector:
+            Style('a', 'b')
+            Style('c', 'd')
+    
+        self.assertEqual(css.render(), self.rendered_css)
+        
+    def test_css_auto_add_different_selector(self):
+        css = CSS()
+        DARWCSS_AUTO = True
+        DARWCSS_SELECTOR = 'test'
+            
+        with css.selector('.home') as test:
+            Style('a', 'b')
+            Style('c', 'd')
+            
+        self.assertEqual(css.render(), self.rendered_css)
+    
+    def test_css_auto_add_different_selector_name_error(self):
+        css = CSS()
+        DARWCSS_AUTO = True
+        DARWCSS_SELECTOR = 'test'
+            
+        with css.selector('.home') as selector:
+            with self.assertRaises(NameError):
+                Style('a', 'b')
+        
+if __name__ == '__main__':
+    unittest.main()

tests/test_numeric.py

+import unittest
+from darwcss.darwcss import NumericValue, render
+
+class TestNumericValue(unittest.TestCase):
+    def test_numeric_render(self):
+        t = NumericValue(5, "px")
+        self.assertEqual(render(t), "5px")
+        
+        x = NumericValue(30, "%")
+        self.assertEqual(render(x), "30%")
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_render.py

+import unittest
+from darwcss.darwcss import render
+
+class TestRender(unittest.TestCase):
+    def test_render_string(self):
+        self.assertEqual(render("merhaba"), "merhaba")
+        self.assertEqual(render("T3est"), "T3est")
+    
+    def test_render_none(self):
+        self.assertEqual(render(None), "none")
+    
+    def test_render_renderable(self):
+        class RenderableObject:
+            def __render__(self) -> str:
+                return "ABC"
+            
+        self.assertEqual(render(RenderableObject()), "ABC")
+
+    def test_render_string_converter(self):
+        self.assertEqual(render(32), "32")
+
+        
+if __name__ == '__main__':
+    unittest.main()