feat: add allow-list options for at-rules, properties, and selectors

fixes #210

Author: Grapedge

docs/rules/use-baseline.md

@@ -104,6 +104,46 @@ This rule accepts an option object with the following properties:
 - `available` (default: `"widely"`)
     - change to `"newly"` to allow features that are at the Baseline newly available stage: features that have been supported on all core browsers for less than 30 months
     - set to a numeric baseline year, such as `2023`, to allow features that became Baseline newly available that year, or earlier
+- `allowAtRules` (default: `[]`) - Specify an array of at-rules that are allowed to be used.
+
+Examples of **correct** code with `{ allowAtRules: ["container"] }`:
+
+```css
+/* eslint css/use-baseline: ["error", { allowAtRules: ["container"] }] */
+
+@container (width > 400px) {
+	h2 {
+		font-size: 1.5em;
+	}
+}
+```
+
+- `allowProperties` (default: `[]`) - Specify an array of properties that are allowed to be used.
+
+Examples of **correct** code with `{ allowProperties: ["user-select"] }`:
+
+```css
+/* eslint css/use-baseline: ["error", { allowProperties: ["user-select"] }] */
+
+.unselectable {
+	user-select: none;
+}
+```
+
+- `allowSelectors` (default: `[]`) - Specify an array of selectors that are allowed to be used.
+
+Examples of **correct** code with `{ allowSelectors: ["nesting", "has"] }`:
+
+```css
+/* eslint css/use-baseline: ["error", { allowSelectors: ["nesting", "has"] }] */
+
+h1 {
+	margin: 0 0 1rem 0;
+	&:has(+ h2) {
+		margin: 0 0 0.25rem 0;
+	}
+}
+```
 
 ## When Not to Use It
 

src/rules/use-baseline.js

@@ -28,7 +28,10 @@ import { namedColors } from "../data/colors.js";
  * @import { Identifier, FunctionNodePlain } from "@eslint/css-tree"
  * @typedef {"notBaselineProperty" | "notBaselinePropertyValue" | "notBaselineAtRule" | "notBaselineType" | "notBaselineMediaCondition" | "notBaselineSelector"} UseBaselineMessageIds
  * @typedef {[{
- *     available?: "widely" | "newly" | number
+ *     available?: "widely" | "newly" | number,
+ *     allowAtRules?: string[],
+ *     allowProperties?: string[],
+ *     allowSelectors?: string[]
  * }]} UseBaselineOptions
  * @typedef {CSSRuleDefinition<{ RuleOptions: UseBaselineOptions, MessageIds: UseBaselineMessageIds }>} UseBaselineRuleDefinition
  */
@@ -430,6 +433,27 @@ export default {
 							},
 						],
 					},
+					allowAtRules: {
+						type: "array",
+						items: {
+							type: "string",
+						},
+						uniqueItems: true,
+					},
+					allowProperties: {
+						type: "array",
+						items: {
+							type: "string",
+						},
+						uniqueItems: true,
+					},
+					allowSelectors: {
+						type: "array",
+						items: {
+							type: "string",
+						},
+						uniqueItems: true,
+					},
 				},
 				additionalProperties: false,
 			},
@@ -438,6 +462,9 @@ export default {
 		defaultOptions: [
 			{
 				available: "widely",
+				allowAtRules: [],
+				allowProperties: [],
+				allowSelectors: [],
 			},
 		],
 
@@ -462,6 +489,9 @@ export default {
 			context.options[0].available,
 		);
 		const supportsRules = new SupportsRules();
+		const allowAtRules = new Set(context.options[0].allowAtRules);
+		const allowProperties = new Set(context.options[0].allowProperties);
+		const allowSelectors = new Set(context.options[0].allowSelectors);
 
 		/**
 		 * Checks a property value identifier to see if it's a baseline feature.
@@ -587,6 +617,10 @@ export default {
 					return;
 				}
 
+				if (allowProperties.has(property)) {
+					return;
+				}
+
 				/*
 				 * Step 1: Check that the property is in the baseline.
 				 *
@@ -723,6 +757,10 @@ export default {
 					return;
 				}
 
+				if (allowAtRules.has(node.name)) {
+					return;
+				}
+
 				const featureStatus = atRules.get(node.name);
 
 				if (!baselineAvailability.isSupported(featureStatus)) {
@@ -756,6 +794,10 @@ export default {
 					return;
 				}
 
+				if (allowSelectors.has(selector)) {
+					return;
+				}
+
 				// if the selector has been tested in a @supports rule, don't check it
 				if (supportsRules.hasSelector(selector)) {
 					return;
@@ -799,6 +841,11 @@ export default {
 			NestingSelector(node) {
 				// NestingSelector implies CSS nesting
 				const selector = "nesting";
+
+				if (allowSelectors.has(selector)) {
+					return;
+				}
+
 				const featureStatus = selectors.get(selector);
 				if (baselineAvailability.isSupported(featureStatus)) {
 					return;

tests/rules/use-baseline.test.js

@@ -88,6 +88,26 @@ ruleTester.run("use-baseline", rule, {
 			code: ".box { backdrop-filter: blur(10px); }",
 			options: [{ available: 2024 }],
 		},
+		{
+			code: "h1:has(+ h2) { margin: 0 0 0.25rem 0; }",
+			options: [{ allowSelectors: ["has"] }],
+		},
+		{
+			code: `label {
+				& input {
+					border: blue 2px dashed;
+				}
+			}`,
+			options: [{ available: 2022, allowSelectors: ["nesting"] }],
+		},
+		{
+			code: "@container (min-width: 800px) { a { color: red; } }",
+			options: [{ available: 2022, allowAtRules: ["container"] }],
+		},
+		{
+			code: "a { accent-color: bar; backdrop-filter: auto }",
+			options: [{ allowProperties: ["accent-color", "backdrop-filter"] }],
+		},
 	],
 	invalid: [
 		{