the redirects are not meant to be permanent

README.md

@@ -2,9 +2,19 @@
 
 ## run it
 
-    npm i
+no external dependencies! no need to `npm i`! woo!
-	cp webring.txt.sample webring.txt && $EDITOR webring.txt
+
-	npm run start
+    cp webring.txt.sample webring.txt && $EDITOR webring.txt
+    npm run start
+
+## configuration
+
+the server listens on port `$PORT` (default 80) and loads the list of
+participating sites from the file `$SITES_FILE` (default `webring.txt`).
+
+the sites file is a newline-separated list of URLs; leading and trailing
+whitespace, empty lines, and lines starting with `#` are ignored. you can test
+out the format using [this regexr link](https://regexr.com/?expression=/^\s*([^%23\s].*)\s*$/gm&text=%23%20sample%20SITES_FILE%0A%0A%23%20my%20friend%20alice%20who%20is%20cool%0Ahttps%3A%2F%2Falices.awesome.website%0A%0A%23%20my%20other%20friend%20bob%20who%20is%20neat%20as%20well%0Ahttp%3A%2F%2Fsome.shared.domain%2F~bob%0A&tool=list&input=your.webring.server/next?from=$1\n).
 
 ## link to webring sites
 

dprint.json

@@ -0,0 +1,29 @@
+{
+	"typescript": {
+		"lineWidth": 80,
+		"useTabs": true,
+		"quoteStyle": "alwaysSingle",
+		"quoteProps": "consistent",
+		"useBraces": "always",
+		"arrowFunction.useParentheses": "preferNone",
+		"enumDeclaration.memberSpacing": "newLine",
+		"spaceSurroundingProperties": false,
+		"exportDeclaration.spaceSurroundingNamedExports": false,
+		"importDeclaration.spaceSurroundingNamedImports": false,
+		"constructor.spaceBeforeParentheses": true,
+		"functionDeclaration.spaceBeforeParentheses": true,
+		"functionExpression.spaceBeforeParentheses": true,
+		"getAccessor.spaceBeforeParentheses": true,
+		"setAccessor.spaceBeforeParentheses": true,
+		"method.spaceBeforeParentheses": true
+	},
+	"markdown": {},
+	"excludes": [
+		"**/node_modules",
+		"**/*-lock.json"
+	],
+	"plugins": [
+		"https://plugins.dprint.dev/typescript-0.86.1.wasm",
+		"https://plugins.dprint.dev/markdown-0.15.3.wasm"
+	]
+}

index.mjs

@@ -1,30 +1,30 @@
-import * as fs from 'node:fs';
+import {readFileSync} from 'node:fs';
-import express from 'express';
+import {createServer} from 'node:http';
+import {URL} from 'node:url';
 
-const sites = fs.readFileSync('./webring.txt', 'utf-8')
+const data = readFileSync(process.env.SITES_FILE || 'webring.txt', 'utf-8');
-	// split lines
+const sites = [...data.matchAll(/^\s*([^#\s].*)\s*$/gm)].map(match => match[1]);
-	.split(/\r?\n/)
-	// trim whitespace from each line
-	.map(site => site.trim())
-	// exclude empty lines and lines that start with # because why not
-	.filter(site => site && !site.startsWith('#'));
 
-// modulo that does the right thing with negatives
+const text = (response, body, code = 200) => {
-// https://stackoverflow.com/a/4467559
+	response.writeHead(code, {'Content-Type': 'text/plain'}).write(body);
-const mod = (n, m) => ((n % m) + m) % m;
+	response.end();
+};
+const redirect = (res, url) => res.writeHead(302, {Location: url}).end();
 
-function handle (offset, request, response) {
+const toSite = (response, from, offset) => {
-	const from = request.query.from;
 	const index = sites.findIndex(site => site === from);
 	if (!from || index === -1) {
-		response.status(400).send('the provided site is not in the webring');
+		return text(response, 'the provided site is not in the webring', 400);
-		return;
 	}
-	response.redirect(301, sites[mod(index + offset, sites.length)]);
+	redirect(response, sites[(index + offset + sites.length) % sites.length]);
-}
+};
 
-express()
+const pathHandlers = {
-	.get('/prev', (request, response) => handle(-1, request, response))
+	'/prev': (response, query) => toSite(response, query.get('from'), -1),
-	.get('/next', (request, response) => handle(+1, request, response))
+	'/next': (response, query) => toSite(response, query.get('from'), +1),
-	.get('/list', (_, response) => response.type('txt').send(sites.join('\n')))
+	'/list': response => text(response, sites.join('\n')),
-	.listen(process.env.PORT || 8080);
+};
+createServer((request, response) => {
+	const url = new URL(request.url, `http://${request.headers.host}`);
+	pathHandlers[url.pathname]?.(response, url.searchParams);
+}).listen(process.env.PORT || 80);

package.json

@@ -4,12 +4,13 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "start": "node index.mjs"
+    "start": "node index.mjs",
+    "fmt": "dprint fmt"
   },
   "keywords": [],
   "author": "",
-  "license": "ISC",
+  "license": "WTFPL",
-  "dependencies": {
+  "devDependencies": {
-    "express": "^4.18.2"
+    "dprint": "^0.40.2"
   }
 }