[css] path completion in web

extensions/css-language-features/server/src/requests.ts

@@ -4,7 +4,6 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { URI } from 'vscode-uri';
-import { endsWith, startsWith } from './utils/strings';
 import { RequestType, Connection } from 'vscode-languageserver';
 import { RuntimeEnvironment } from './cssServer';
 
@@ -114,14 +113,48 @@ export function basename(uri: string) {
 	return uri.substr(lastIndexOfSlash + 1);
 }
 
+const Slash = '/'.charCodeAt(0);
+const Dot = '.'.charCodeAt(0);
+
+export function isAbsolutePath(path: string) {
+	return path.charCodeAt(0) === Slash;
+}
+
+export function resolvePath(uriString: string, path: string): string {
+	if (isAbsolutePath(path)) {
+		const uri = URI.parse(uriString);
+		const parts = path.split('/');
+		return uri.with({ path: normalizePath(parts) }).toString();
+	}
+	return joinPath(uriString, path);
+}
+
+export function normalizePath(parts: string[]): string {
+	const newParts: string[] = [];
+	for (const part of parts) {
+		if (part.length === 0 || part.length === 1 && part.charCodeAt(0) === Dot) {
+			// ignore
+		} else if (part.length === 2 && part.charCodeAt(0) === Dot && part.charCodeAt(1) === Dot) {
+			newParts.pop();
+		} else {
+			newParts.push(part);
+		}
+	}
+	if (parts.length > 1 && parts[parts.length - 1].length === 0) {
+		newParts.push('');
+	}
+	let res = newParts.join('/');
+	if (parts[0].length === 0) {
+		res = '/' + res;
+	}
+	return res;
+}
+
 export function joinPath(uriString: string, ...paths: string[]): string {
 	const uri = URI.parse(uriString);
-	let uriPath = uri.path;
+	const parts = uri.path.split('/');
 	for (let path of paths) {
-		if (!endsWith(uriPath, '/') && !startsWith(path, '/')) {
-			uriPath += '/';
-		}
-		uriPath += path;
+		parts.push(...path.split('/'));
 	}
-	return uri.with({ path: uriPath }).toString();
+	return uri.with({ path: normalizePath(parts) }).toString();
 }