add resolver to resolve absolute path in @import

.tape.js

@@ -105,3 +105,20 @@ test(rule, {
 	accept,
 	reject
 });
+
+accept = [
+	{ code: '@import "import-custom-properties-absolute.css"; body { background-color: var(--brand-red); background: var(--brand-green); }' }
+];
+reject = [];
+
+test(rule, {
+	ruleName,
+	config: [true, {
+		resolver: {
+			paths: './test'
+		}
+	}],
+	skipBasicChecks,
+	accept,
+	reject
+});

README.md

@@ -110,6 +110,28 @@ objects.
 }
 ```
 
+### resolver
+
+Use this option to configure how the rule solve paths of `@import` rules.
+
+```js
+// .stylelintrc
+{
+  "plugins": [
+    "stylelint-value-no-unknown-custom-properties"
+  ],
+  "rules": {
+    "csstools/value-no-unknown-custom-properties": [true, {
+      "resolver": {
+        "extensions": [".css"], // => default to [".css"]
+        "paths": ["./assets/css", "./static/css"] // => paths to look for files, default to []
+        "moduleDirectories": ["node_modules"] // => modules folder to look for files, default to ["node_modules"]
+      }
+    }]
+  }
+}
+```
+
 [cli-img]: https://img.shields.io/travis/csstools/stylelint-value-no-unknown-custom-properties.svg
 [cli-url]: https://travis-ci.org/csstools/stylelint-value-no-unknown-custom-properties
 [git-img]: https://img.shields.io/badge/support-chat-blue.svg

package.json

@@ -26,7 +26,8 @@
     "node": ">=10.0.0"
   },
   "dependencies": {
-    "postcss-values-parser": "^3.2.1"
+    "postcss-values-parser": "^3.2.1",
+    "resolve": "^1.20.0"
   },
   "devDependencies": {
     "@babel/core": "^7.9.6",

src/index.js

@@ -7,10 +7,11 @@ import ruleName from './lib/rule-name';
 export default stylelint.createPlugin(ruleName, (method, opts) => {
 	// sources to import custom selectors from
 	const importFrom = [].concat(Object(opts).importFrom || []);
+	const resolver = Object(opts).resolver || {};
 
 	// promise any custom selectors are imported
 	const customPropertiesPromise = isMethodEnabled(method)
-		? getCustomPropertiesFromImports(importFrom)
+		? getCustomPropertiesFromImports(importFrom, resolver)
 	: {};
 
 	return async (root, result) => {
@@ -26,7 +27,7 @@ export default stylelint.createPlugin(ruleName, (method, opts) => {
 			// all custom properties from the file and imports
 			const customProperties = Object.assign(
 				await customPropertiesPromise,
-				await getCustomPropertiesFromRoot(root)
+				await getCustomPropertiesFromRoot(root, resolver)
 			);
 
 			// validate the css root

src/lib/get-custom-properties-from-imports.js

@@ -6,11 +6,11 @@ import getCustomPropertiesFromRoot from './get-custom-properties-from-root';
 /* Get Custom Properties from CSS File
 /* ========================================================================== */
 
-async function getCustomPropertiesFromCSSFile(from) {
+async function getCustomPropertiesFromCSSFile(from, resolver) {
 	const css = await readFile(from);
 	const root = postcss.parse(css, { from });
 
-	return await getCustomPropertiesFromRoot(root);
+	return await getCustomPropertiesFromRoot(root, resolver);
 }
 
 /* Get Custom Properties from Object
@@ -47,7 +47,7 @@ async function getCustomPropertiesFromJSFile(from) {
 /* Get Custom Properties from Sources
 /* ========================================================================== */
 
-export default function getCustomPropertiesFromSources(sources) {
+export default function getCustomPropertiesFromSources(sources, resolver) {
 	return sources.map(source => {
 		if (source instanceof Promise) {
 			return source;
@@ -74,7 +74,7 @@ export default function getCustomPropertiesFromSources(sources) {
 		const { type, from } = await source;
 
 		if (type === 'css') {
-			return Object.assign(await customProperties, await getCustomPropertiesFromCSSFile(from));
+			return Object.assign(await customProperties, await getCustomPropertiesFromCSSFile(from, resolver));
 		}
 
 		if (type === 'js') {

src/lib/get-custom-properties-from-root.js

@@ -1,9 +1,10 @@
 import { promises as fs } from 'fs';
 import path from 'path';
 import postcss from 'postcss';
+import { resolveId } from './resolve-id'
 
 // return custom selectors from the css root, conditionally removing them
-export default async function getCustomPropertiesFromRoot(root) {
+export default async function getCustomPropertiesFromRoot(root, resolver) {
 	// initialize custom selectors
 	let customProperties = {};
 
@@ -17,8 +18,19 @@ export default async function getCustomPropertiesFromRoot(root) {
 	const importPromises = [];
 	root.walkAtRules('import', atRule => {
 		const fileName = atRule.params.replace(/['|"]/g, '');
-		const resolvedFileName = path.resolve(sourceDir, fileName);
-		importPromises.push(getCustomPropertiesFromCSSFile(resolvedFileName));
+
+		if (path.isAbsolute(fileName)) {
+			importPromises.push(getCustomPropertiesFromCSSFile(fileName, resolver));
+		} else {
+			const promise = resolveId(fileName, sourceDir, {
+				paths: resolver.paths,
+				extensions: resolver.extensions,
+				moduleDirectories: resolver.moduleDirectories
+			})
+				.then((filePath) => getCustomPropertiesFromCSSFile(filePath, resolver))
+				.catch(() => {})
+			importPromises.push(promise)
+		}
 	});
 
 	(await Promise.all(importPromises)).forEach(propertiesFromImport => {
@@ -41,12 +53,12 @@ export default async function getCustomPropertiesFromRoot(root) {
 const customPropertyRegExp = /^--[A-z][\w-]*$/;
 
 
-async function getCustomPropertiesFromCSSFile(from) {
+async function getCustomPropertiesFromCSSFile(from, resolver) {
 	try {
 		const css = await fs.readFile(from, 'utf8');
 		const root = postcss.parse(css, { from });
 
-		return await getCustomPropertiesFromRoot(root);
+		return await getCustomPropertiesFromRoot(root, resolver);
 	} catch (e) {
 		return {};
 	}

src/lib/resolve-id.js

@@ -0,0 +1,19 @@
+import resolve from 'resolve'
+
+export function resolveId(id, basedir, {
+		paths = [],
+		moduleDirectories = ['node_modules'],
+		extensions = ['.css']
+	} = {}
+) {
+  const resolveOpts = {
+    basedir,
+    moduleDirectory: moduleDirectories,
+    paths,
+	extensions,
+    preserveSymlinks: false,
+  }
+  return new Promise((res, rej) => {
+    resolve(id, resolveOpts, (err, resolvedPath) => err ? rej(err) : res(resolvedPath))
+  })
+}

test/import-custom-properties-absolute.css

@@ -0,0 +1,5 @@
+@import 'import-custom-properties-2.css';
+
+:root {
+	--brand-red: red;
+}