Accept CSS color syntax supported by plotly.js in ColorValidator

Allow signed and exponent numbers, angle units other than deg, the none
keyword, any color() color space and the transparent keyword. These are
all accepted by plotly.js 4 but were rejected by the Python validator.

Author: ShawnNotFound

_plotly_utils/basevalidators.py

@@ -1138,13 +1138,24 @@ class ColorValidator(BaseValidator):
     },
     """
 
-    re_spaces_to_remove = re.compile(r"(?<!(\d|%|g)) | (?!\d)")
-
     re_hex = re.compile(
         r"#([A-Fa-f0-9]{3}|[A-Fa-f0-9]{4}|[A-Fa-f0-9]{6}|[A-Fa-f0-9]{8})"
     )
+
+    # A CSS color function argument: a number (which may be signed or use an
+    # exponent) with an optional percent sign or angle unit, or `none`.
+    _re_css_value = (
+        r"(?:[+-]?(?:\d+\.?\d*|\.\d+)(?:e[+-]?\d+)?(?:%|deg|grad|rad|turn)?|none)"
+    )
+    _re_css_sep = r"(?:\s*,\s*|\s+)"
+    _re_css_alpha_sep = r"(?:\s*[,/]\s*|\s+)"
     re_rgb_etc = re.compile(
-        r"((rgb|hsl)a?|hwb|(ok)?(lab|lch))\([\d.]+(%|deg)?([ ,] ?[\d.]+%?){2}([ /,] ?[\d.]+%?)?\)|color\([\w-]+([ ,] ?[\d.]+){3,4}\)"
+        r"(?:(?:rgb|hsl)a?|hwb|(?:ok)?(?:lab|lch))\s*\(\s*"
+        rf"{_re_css_value}{_re_css_sep}{_re_css_value}{_re_css_sep}{_re_css_value}"
+        rf"(?:{_re_css_alpha_sep}{_re_css_value})?\s*\)"
+        r"|color\s*\(\s*[a-z][\w-]*"
+        rf"(?:{_re_css_sep}{_re_css_value}){{3}}"
+        rf"(?:{_re_css_alpha_sep}{_re_css_value})?\s*\)"
     )
     re_ddk = re.compile(r"var\(\-\-.*\)")
 
@@ -1290,6 +1301,7 @@ class ColorValidator(BaseValidator):
         "teal",
         "thistle",
         "tomato",
+        "transparent",
         "turquoise",
         "violet",
         "wheat",
@@ -1443,12 +1455,7 @@ def perform_validate_coerce(v, allow_number=None):
             # If not allow_numbers then value must be a string
             return None
         else:
-            # Remove spaces so regexes don't need to bother with them.
-            # Don't remove spaces between two digits, though.
-            v_normalized = v.strip()
-            v_normalized = re.sub(" +", " ", v_normalized)
-            v_normalized = re.sub(ColorValidator.re_spaces_to_remove, "", v_normalized)
-            v_normalized = v_normalized.lower()
+            v_normalized = v.strip().lower()
 
             # if ColorValidator.re_hex.fullmatch(v_normalized):
             if fullmatch(ColorValidator.re_hex, v_normalized):

tests/test_plotly_utils/validators/test_color_validator.py

@@ -57,6 +57,18 @@ def validator_aok_colorscale():
     "lab(70 15 50)",
     "lch(70 15 180)",
     "color(display-p3 1 0 0)",
+    "color(srgb 1 0 0)",
+    "color(a98-rgb 1 0 0 / 0.5)",
+    "lab(50% -40 59.5)",
+    "oklab(0.6 0.1 -0.05)",
+    "lch(52% 72 -30)",
+    "hsl(-30, 50%, 50%)",
+    "hsl(0.5turn 60% 40%)",
+    "hsl(1rad 60% 40%)",
+    "hsl(none 60% 40%)",
+    "rgb(255 0 0 / none)",
+    "rgb(1e2, 0, 0)",
+    "transparent",
 ]
 
 INVALID_COLORS_WRONG_TYPE = [
@@ -72,6 +84,12 @@ def validator_aok_colorscale():
     "hsl(0, 1%0000%, 50%)",
     "hsv(0, 100%, 100%)",
     "hsva(0, 100%, 100%, 50%)",
+    "currentcolor",
+    "rgb(255, 0)",
+    "rgb(255 0 0 /)",
+    "rgb(1-2 3 4)",
+    "color(1 0 0)",
+    "color(srgb 1 0)",
 ]