feature(strict_color_names): Added a rule for color validation. (lyft#60

)
brightec · Mar 3, 2021 · 2e14b59 · 2e14b59
1 parent af66750
commit 2e14b59
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Showing 2 changed files with 26 additions and 7 deletions.
diff --git a/README.md b/README.md
@@ -50,7 +50,7 @@ in the .xib or .storyboard file.
 
 - `named_colors`
 
-  Ensures all colors are using named colors from an asset catalog. Configure `ignore_alpha` (default is `false`) in a custom rule configuration using `rules_config` (see below) if you’d like to ignore colors with alpha.
+  Ensures all colors are using named colors from an asset catalog. Configure `allowed_colors` to limit the colors to a subset (default is all named colors are allowed), `allow_system_colors` (default is `false`) and `ignore_alpha` (default is `false`) in a custom rule configuration using `rules_config` (see below).
 
 - `no_trait_variations`
 

diff --git a/xiblint/rules/named_colors.py b/xiblint/rules/named_colors.py
@@ -8,10 +8,14 @@ class NamedColors(Rule):
 
     Example configuration:
     {
+      "allowed_colors": ["CustomRed", "CustomGreen"],
+      "allow_system_colors": true,
       "ignore_alpha": true
     }
     """
     def check(self, context):  # type: (XibContext) -> None
+        allowed_colors = self.config.get('allowed_colors', [])
+        allow_system_colors = self.config.get('allow_system_colors', False)
         ignore_alpha = self.config.get('ignore_alpha', False)
 
         for element in context.tree.findall(".//color"):
@@ -24,16 +28,31 @@ def check(self, context):  # type: (XibContext) -> None
             if element.parent.tag == 'namedColor':
                 continue
 
+            # Skip <color> tags part of a system color definition
+            if element.parent.tag == 'systemColor':
+                continue
+
             # Skip colors with alpha (if configured)
-            if ignore_alpha and element.get('alpha') != '1':
+            if ignore_alpha and element.get('alpha') is not None and element.get('alpha') != '1':
+                continue
+
+            # If `systemColor` or `catalog` is present, it's a named system color
+            if (
+                    element.get('systemColor') is not None or
+                    element.get('cocoaTouchSystemColor') is not None or
+                    element.get('catalog') is not None
+            ):
+                if not allow_system_colors:
+                    context.error(element, "Use of named system colors is not allowed. Use a named color instead.")
                 continue
 
             # Require a name
-            if element.get('name') is None:
+            color_name = element.get('name')
+            if color_name is None:
                 context.error(element, "Use of custom colors is not allowed. Use a named color instead.")
                 continue
 
-            # If `catalog` is present, it's a named system color
-            if element.get('catalog') is not None:
-                context.error(element, "Use of named system colors is not allowed. Use a named color instead.")
-                continue
+            # If allowed_colors is set, verify that color_name is included
+            if allowed_colors and color_name not in allowed_colors:
+                context.error(element, '"{}" is not one of the allowed colors: "{}".'
+                              .format(color_name, allowed_colors))