Strip ANSI escape sequences

References: https://todo.sr.ht/~emersion/gamja/11

components/buffer-header.js

@@ -1,5 +1,6 @@
 import { html, Component } from "/lib/index.js";
 import linkify from "/lib/linkify.js";
+import { strip as stripANSI } from "/lib/ansi.js";
 import { BufferType } from "/state.js";
 
 const Status = {
@@ -29,10 +30,12 @@ export default function BufferHeader(props) {
 		var serverInfo = props.buffer.serverInfo;
 		description = `Connected to ${serverInfo.name}`;
 	} else if (props.buffer.topic) {
-		description = linkify(props.buffer.topic);
+		description = linkify(stripANSI(props.buffer.topic));
 	} else if (props.buffer.who) {
 		var who = props.buffer.who;
 
+		var realname = stripANSI(who.realname || "");
+
 		var status = Status.HERE;
 		if (who.away) {
 			status = Status.GONE;
@@ -41,7 +44,7 @@ export default function BufferHeader(props) {
 			status = Status.OFFLINE;
 		}
 
-		description = html`<${NickStatus} status=${status}/> ${who.realname} (${who.username}@${who.hostname})`;
+		description = html`<${NickStatus} status=${status}/> ${realname} (${who.username}@${who.hostname})`;
 	} else if (props.buffer.offline) {
 		// User is offline, but we don't have WHO information
 		description = html`<${NickStatus} status=${Status.OFFLINE}/> ${props.buffer.name}`;

components/buffer.js

@@ -1,6 +1,7 @@
 import { html, Component } from "/lib/index.js";
 import linkify from "/lib/linkify.js";
 import * as irc from "/lib/irc.js";
+import { strip as stripANSI } from "/lib/ansi.js";
 import { BufferType, getNickURL, getMessageURL } from "/state.js";
 
 function djb2(s) {
@@ -64,10 +65,10 @@ class LogLine extends Component {
 				var action = text.slice(actionPrefix.length, -1);
 
 				lineClass = "me-tell";
-				content = html`* ${createNick(msg.prefix.name)} ${linkify(action)}`;
+				content = html`* ${createNick(msg.prefix.name)} ${linkify(stripANSI(action))}`;
 			} else {
 				lineClass = "talk";
-				content = html`${"<"}${createNick(msg.prefix.name)}${">"} ${linkify(text)}`;
+				content = html`${"<"}${createNick(msg.prefix.name)}${">"} ${linkify(stripANSI(text))}`;
 			}
 			break;
 		case "JOIN":
@@ -94,7 +95,7 @@ class LogLine extends Component {
 		case "TOPIC":
 			var topic = msg.params[1];
 			content = html`
-				${createNick(msg.prefix.name)} changed the topic to: ${linkify(topic)}
+				${createNick(msg.prefix.name)} changed the topic to: ${linkify(stripANSI(topic))}
 			`;
 			break;
 		default:

lib/ansi.js

@@ -0,0 +1,53 @@
+// See https://modern.ircdocs.horse/formatting.html
+
+const BOLD = "\x02";
+const ITALIC = "\x1D";
+const UNDERLINE = "\x1F";
+const STRIKETHROUGH = "\x1E";
+const MONOSPACE = "\x11";
+const COLOR = "\x03";
+const COLOR_HEX = "\x04";
+const REVERSE_COLOR = "\x16";
+const RESET = "\x0F";
+
+function isDigit(ch) {
+	return ch >= "0" && ch <= "9";
+}
+
+export function strip(text) {
+	var out = "";
+	for (var i = 0; i < text.length; i++) {
+		var ch = text[i];
+		switch (ch) {
+		case BOLD:
+		case ITALIC:
+		case UNDERLINE:
+		case STRIKETHROUGH:
+		case MONOSPACE:
+		case REVERSE_COLOR:
+		case RESET:
+			break; // skip
+		case COLOR:
+			if (!isDigit(text[i + 1])) {
+				break;
+			}
+			i++;
+			if (isDigit(text[i + 1])) {
+				i++;
+			}
+			if (text[i + 1] == "," && isDigit(text[i + 2])) {
+				i += 2;
+				if (isDigit(text[i + 1])) {
+					i++;
+				}
+			}
+			break;
+		case COLOR_HEX:
+			i += 6;
+			break;
+		default:
+			out += ch;
+		}
+	}
+	return out;
+}