`) are left in place — only fully paired blocks, whose contents would
* otherwise dominate the title, are dropped.
*/
export function stripXmlBlocks(message: string): string {
return message.replace(XML_BLOCK, " ");
}
/** Truncate full commit-hash-like hex runs (≥12 chars) to a short 7-char prefix. */
export function shortenHashes(message: string): string {
return message.replace(LONG_HEX_RUN, match => match.slice(0, SHORT_HASH_CHARS));
}
/**
* Middle-truncate cleaned text, preserving 2/3 of the available space from the
* head and 1/3 from the tail. The omission marker counts toward the bound.
*/
export function truncateTinyMessage(message: string): string {
if (message.length <= MAX_TINY_MESSAGE_CHARS) return message;
let omitted = message.length - MAX_TINY_MESSAGE_CHARS;
let marker = "";
let headChars = 0;
let tailChars = 0;
// The omitted count changes the marker width; two passes converge because
// only the decimal digit count can change.
for (let pass = 0; pass < 2; pass++) {
marker = `\n[… ${omitted} chars omitted …]\n`;
const keptChars = Math.max(0, MAX_TINY_MESSAGE_CHARS - marker.length);
headChars = Math.ceil((keptChars * 2) / 3);
tailChars = keptChars - headChars;
omitted = message.length - headChars - tailChars;
}
marker = `\n[… ${omitted} chars omitted …]\n`;
return `${message.slice(0, headChars)}${marker}${message.slice(-tailChars)}`;
}
/**
* Strip fenced code blocks from a message before titling.
*
* Small title models latch onto literal text inside code blocks — e.g. a pasted
* UI mockup containing "Welcome to Claude Code v2.1.158" yields that string as
* the title instead of the surrounding intent. Removing fenced blocks leaves the
* prose that actually describes the task. Inline code (single backticks) is kept
* — it is short, high-signal context like `/login`.
*
* Falls back to the original message when stripping leaves too little to title
* (a message that is essentially just a code block).
*/
export function stripCodeBlocks(message: string): string {
const cleaned = collapseWhitespace(message.replace(FENCED_CODE_BLOCK, " "));
return cleaned.length >= MIN_STRIPPED_TITLE_CHARS ? cleaned : message;
}
/** Collapse horizontal whitespace runs and excess blank lines, then trim. */
function collapseWhitespace(message: string): string {
return message
.replace(/[ \t]+/g, " ")
.replace(/\n{3,}/g, "\n\n")
.trim();
}
/**
* Clean noise from message content without applying the length bound.
* The raw input is capped at {@link RAW_SCAN_EDGE_CHARS} per end, fenced blocks
* are stripped, and only then is the remainder windowed to
* {@link CLEAN_WINDOW_EDGE_CHARS} per end before paired-tag stripping, so prose
* between large code blocks is preserved.
*/
export function cleanTinyMessage(message: string): string {
const fenceStripped = stripCodeBlocks(stripAnsi(windowEdges(message, RAW_SCAN_EDGE_CHARS)));
return collapseWhitespace(shortenHashes(stripXmlBlocks(windowEdges(fenceStripped, CLEAN_WINDOW_EDGE_CHARS))));
}
/** Apply the shared tiny-model cleanup and middle-truncation policy. */
export function preprocessTinyMessage(message: string): string {
return truncateTinyMessage(cleanTinyMessage(message));
}
/** Envelope produced by {@link formatTitleConversationContext}. Anchored to both
* ends so ordinary user text merely containing a chat snippet never matches. */
const CHAT_CONTEXT_ENVELOPE = /^\s*
[\s\S]*<\/chat>\s*$/;
/** Structural tags emitted by {@link formatTitleConversationContext}. */
const CHAT_SCAFFOLD_TAG = /<\/?(?:chat|user|assistant|think)>/g;
/** True when `message` is a preformatted replan context from
* {@link formatTitleConversationContext} — already cleaned per turn and
* bounded, so it must bypass {@link preprocessTinyMessage} (whose paired-tag
* stripping would consume the entire envelope). */
export function isPreformattedChatContext(message: string): boolean {
return CHAT_CONTEXT_ENVELOPE.test(message);
}
/** Drop the ``/``/``/`` scaffolding, keeping turn
* text. Used for token-level signal checks on preformatted contexts. */
export function stripChatScaffolding(message: string): string {
return message.replace(CHAT_SCAFFOLD_TAG, " ");
}
/** Wrap a preprocessed user message for title generation. Preformatted replan
* contexts pass through untouched. */
export function formatTitleUserMessage(message: string): string {
if (isPreformattedChatContext(message)) return message;
return `\n${preprocessTinyMessage(message)}\n`;
}
/** One recent conversation turn supplied to title refresh after replanning. */
export interface TitleConversationTurn {
role: "user" | "assistant";
text?: string;
thinking?: string;
}
/** Format preprocessed recent context for title generation after a todo replan. */
export function formatTitleConversationContext(turns: readonly TitleConversationTurn[]): string {
const formattedTurns: string[] = [];
for (const turn of turns) {
const sections: string[] = [];
// Clean raw content before adding structural tags so paired-tag stripping
// cannot consume the ``/`` scaffolding added below.
const text = cleanTinyMessage(turn.text ?? "").trim();
if (text) sections.push(text);
const thinking = turn.role === "assistant" ? cleanTinyMessage(turn.thinking ?? "").trim() : "";
if (thinking) sections.push(`\n${thinking}\n`);
if (sections.length === 0) continue;
formattedTurns.push(`<${turn.role}>\n${sections.join("\n\n")}\n`);
}
if (formattedTurns.length === 0) return "";
return truncateTinyMessage(`\n${formattedTurns.join("\n\n")}\n`);
}