Add discouraged cssom interfaces (#2629)

Co-authored-by: Daniel D. Beck <daniel@ddbeck.com>

Author: captainbrosset

features/css-object-model-discouraged.yml

@@ -0,0 +1,34 @@
+name: CSS object model (DOM level 2)
+description: The DOM level 2 style specification defined interfaces to access and modify CSS styles, such as `CSSValue` and `CSSPrimitiveValue`, that were later excluded from the CSS object model.
+spec: https://www.w3.org/TR/DOM-Level-2-Style/
+group: cssom
+discouraged:
+  according_to:
+    - https://www.w3.org/TR/DOM-Level-2-Style/#Overview-status
+  alternatives:
+    - css-object-model
+compat_features:
+  - api.CSSPrimitiveValue
+  - api.CSSPrimitiveValue.getCounterValue
+  - api.CSSPrimitiveValue.getFloatValue
+  - api.CSSPrimitiveValue.getRGBColorValue
+  - api.CSSPrimitiveValue.getRectValue
+  - api.CSSPrimitiveValue.getStringValue
+  - api.CSSPrimitiveValue.primitiveType
+  - api.CSSPrimitiveValue.setFloatValue
+  - api.CSSPrimitiveValue.setStringValue
+  - api.CSSValue
+  - api.CSSValue.cssText
+  - api.CSSValue.cssValueType
+  - api.CSSValueList
+  - api.CSSValueList.item
+  - api.CSSValueList.length
+  - api.Counter
+  - api.Counter.identifier
+  - api.Counter.listStyle
+  - api.Counter.separator
+  - api.Rect
+  - api.Rect.bottom
+  - api.Rect.left
+  - api.Rect.right
+  - api.Rect.top

features/css-object-model-discouraged.yml.dist

@@ -0,0 +1,48 @@
+# Generated from: css-object-model-discouraged.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: false
+  support:
+    safari: "10"
+    safari_ios: "10"
+compat_features:
+  # baseline: false
+  # support:
+  #   safari: "3"
+  #   safari_ios: "1"
+  - api.CSSPrimitiveValue
+  - api.CSSPrimitiveValue.getCounterValue
+  - api.CSSPrimitiveValue.getFloatValue
+  - api.CSSPrimitiveValue.getRGBColorValue
+  - api.CSSPrimitiveValue.getRectValue
+  - api.CSSPrimitiveValue.getStringValue
+  - api.CSSPrimitiveValue.setFloatValue
+  - api.CSSPrimitiveValue.setStringValue
+  - api.CSSValue
+  - api.CSSValueList
+  - api.CSSValueList.item
+  - api.Counter
+  - api.Counter.identifier
+  - api.Counter.listStyle
+  - api.Counter.separator
+  - api.Rect
+  - api.Rect.bottom
+  - api.Rect.left
+  - api.Rect.right
+  - api.Rect.top
+
+  # baseline: false
+  # support:
+  #   safari: "7"
+  #   safari_ios: "7"
+  - api.CSSPrimitiveValue.primitiveType
+  - api.CSSValue.cssText
+  - api.CSSValue.cssValueType
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   safari: "10"
+  #   safari_ios: "10"
+  - api.CSSValueList.length

scripts/specs.ts

@@ -100,6 +100,10 @@ const defaultAllowlist: allowlistItem[] = [
     [
         "https://github.com/tc39/proposal-import-attributes/tree/abca60286360b47f9a6be25a28f489c2cb157beb",
         "Allowed because import assertions were replaced in-place by import attributes. Remove this exception when javascript.statements.import.import_assertions is dropped from BCD in June 2026."
+    ],
+    [
+        "https://www.w3.org/TR/DOM-Level-2-Style/",
+        "Allowed because the css-object-model-discouraged feature points to it."
     ]
 ];