fix(server): one lone-surrogate sanitizer, one sanitizeReplacer, one startTunnel

Three copies of the surrogate sanitizer existed with two algorithms
(sanitize.ts regex vs a hand-rolled charCodeAt walk in server.ts — verified
byte-identical across 11 edge cases before converging) plus two identical
sanitizeReplacer definitions each wrapping a different copy. sanitize.ts is
now the single source of truth; the runs-INSIDE-JSON.stringify egress
invariant is unchanged at every call site and its pin tests were adapted to
the new import shape without losing intent.

The ngrok tunnel-start sequence existed three times in server.ts — the
/tunnel/start route and the BROWSE_TUNNEL=1 autostart were line-for-line
equivalent (a comment admitted 'Same cleanup as /tunnel/start's error path').
One startTunnel() now owns the ephemeral loopback bind, the pre-send egress
receipt, the state-file RMW via tmpStatePath(), and the ordered error-path
cleanup; callers keep their distinct response surfaces. The
BROWSE_TUNNEL_LOCAL_ONLY test path shares nothing (no ngrok, different state
field) and deliberately stays separate.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Garry Tan 2026-08-14 19:29:29 -07:00
parent 60134c4320
commit e426293017
No known key found for this signature in database
GPG Key ID: C1F69E85C74EFE1D
5 changed files with 231 additions and 195 deletions

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@ -17,6 +17,21 @@ export function stripLoneSurrogates(s: string): string {
return s.replace(LONE_SURROGATE_HIGH, '<27>').replace(LONE_SURROGATE_LOW, '<27>');
}
/**
* JSON.stringify replacer that strips lone UTF-16 surrogates from string
* values before they get escape-encoded. Pair with stringify when the
* consumer will JSON.parse the payload back into JS strings (SSE clients
* do this). Required at every JSON/SSE egress that ships page-content-derived
* fields see CLAUDE.md "Unicode sanitization at server egress".
*
* The replacer must run INSIDE the encoding pipeline: post-stringify regex
* is a no-op because JSON.stringify has already converted \uD800 into the
* literal escape text "\\ud800" before a regex could see the surrogate.
*/
export function sanitizeReplacer(_key: string, value: unknown): unknown {
return typeof value === 'string' ? stripLoneSurrogates(value) : value;
}
// Matches \uD8XX-\uDFXX escape text where the pair is not completed by an
// adjacent \uDC00-\uDFFF (high) or preceded by \uD800-\uDBFF (low).
const LONE_SURROGATE_HIGH_ESCAPE = /\\u[Dd][89ABab][0-9A-Fa-f]{2}(?!\\u[Dd][C-Fc-f][0-9A-Fa-f]{2})/g;

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@ -45,7 +45,7 @@ import { inspectElement, modifyStyle, resetModifications, getModificationHistory
import { safeUnlink, safeUnlinkQuiet, safeKill } from './error-handling';
import { readAgentRecord, killAgentByRecord, agentRecordPath, spawnTerminalAgent } from './terminal-agent-control';
import { isProcessAlive } from './error-handling';
import { sanitizeBody, stripLoneSurrogateEscapes } from './sanitize';
import { sanitizeBody, stripLoneSurrogateEscapes, stripLoneSurrogates, sanitizeReplacer } from './sanitize';
import { startSocksBridge, testUpstream, type BridgeHandle } from './socks-bridge';
import { parseProxyConfig, toUpstreamConfig, ProxyConfigError } from './proxy-config';
import { writeReceipt } from '../../lib/egress-receipt';
@ -68,41 +68,22 @@ import * as path from 'path';
import * as crypto from 'crypto';
// ─── Unicode Sanitization ───────────────────────────────────────
// Remove unpaired UTF-16 surrogate halves (\uD800\uDFFF). Page DOM text,
// OCR output, and other CDP-sourced strings can contain lone surrogates;
// JSON consumers downstream (Anthropic API in particular) reject them with
// "no low surrogate in string". Valid surrogate pairs (e.g. emoji) survive
// unchanged. Lone halves become U+FFFD (<28>).
// Unpaired UTF-16 surrogate halves (\uD800\uDFFF) in page DOM text, OCR
// output, and other CDP-sourced strings are rejected by JSON consumers
// downstream (Anthropic API in particular: "no low surrogate in string").
// The sanitizers live in sanitize.ts (single source of truth, shared with
// sse-helpers.ts and the read/snapshot pipeline): `stripLoneSurrogates`
// replaces lone halves with U+FFFD (valid pairs like emoji survive), and
// `sanitizeReplacer` runs it on every string value inside JSON.stringify.
//
// INVARIANT: every server egress path that ships page-content strings MUST
// route through this sanitizer. handleCommandInternal wraps the final
// route through the sanitizer. handleCommandInternal wraps the final
// cr.result string (text/plain bodies carry lone surrogates verbatim;
// JSON.stringify already escapes them). The two SSE producers below
// stringify with `sanitizeReplacer` so payload string fields get cleaned
// BEFORE escaping. Plain post-stringify regex is a no-op there because
// JSON.stringify converts \uD800 → "\\ud800" — the regex can't see the
// surrogate after that point.
function sanitizeLoneSurrogates(str: string): string {
return str.replace(/[\uD800-\uDFFF]/g, (match, offset) => {
const code = match.charCodeAt(0);
if (code >= 0xD800 && code <= 0xDBFF) {
const next = str.charCodeAt(offset + 1);
if (next >= 0xDC00 && next <= 0xDFFF) return match;
}
if (code >= 0xDC00 && code <= 0xDFFF) {
const prev = str.charCodeAt(offset - 1);
if (prev >= 0xD800 && prev <= 0xDBFF) return match;
}
return '<27>';
});
}
// JSON.stringify replacer that sanitizes string values before they get
// escape-encoded. Pair with stringify when the consumer will JSON.parse the
// payload back into JS strings (SSE clients do this).
function sanitizeReplacer(_key: string, value: unknown): unknown {
return typeof value === 'string' ? sanitizeLoneSurrogates(value) : value;
}
// JSON.stringify already escapes them). The SSE producers stringify with
// `sanitizeReplacer` so payload string fields get cleaned BEFORE escaping.
// Plain post-stringify regex is a no-op there because JSON.stringify
// converts \uD800 → "\\ud800" — the regex can't see the surrogate after
// that point.
// ─── Config ─────────────────────────────────────────────────────
const config = resolveConfig();
@ -402,6 +383,100 @@ async function closeTunnel(): Promise<void> {
tunnelActive = false;
}
/**
* Result of startTunnel(). `stage` tells the caller which half failed so it
* can keep its distinct error surface: 'bind' = the tunnel-surface Bun.serve
* listener could not bind (nothing to clean up), 'ngrok' = anything after the
* bind (ngrok forward, egress receipt, state-file write) startTunnel has
* already torn down both ngrok and the Bun listener by the time it returns.
*/
type StartTunnelResult =
| { ok: true; url: string }
| { ok: false; stage: 'bind' | 'ngrok'; error: Error };
/**
* Start the ngrok tunnel using the dual-listener pattern: bind a dedicated
* tunnel-surface listener on an ephemeral 127.0.0.1 port and point
* ngrok.forward() at THAT port the local listener (which serves
* /extension-token, /cookie-picker, /inspector/*, welcome, etc.) is never
* exposed to ngrok. Shared by the /tunnel/start route handler (which passes
* its in-closure makeFetchHandler('tunnel')) and the BROWSE_TUNNEL=1
* auto-start flow in start() (which passes handle.fetchTunnel from the
* factory). The BROWSE_TUNNEL_LOCAL_ONLY=1 test path does NOT use this
* helper it binds the tunnel surface with no ngrok forwarding at all.
*
* Hard fail on listener bind (`stage: 'bind'`) NEVER fall back to the
* local port, which would silently defeat the whole security property.
*
* On success, sets the module tunnel state (tunnelListener / tunnelUrl /
* tunnelServer / tunnelActive) and records the tunnel in the state file.
*/
async function startTunnel(opts: {
fetchHandler: (req: Request, server: any) => Promise<Response>;
authtoken: string;
consent: string;
}): Promise<StartTunnelResult> {
// Bind the tunnel listener on an ephemeral port. HARD FAIL if this
// errors — never fall back to the local port.
let boundTunnel: ReturnType<typeof Bun.serve>;
try {
boundTunnel = Bun.serve({
port: 0,
hostname: '127.0.0.1',
fetch: opts.fetchHandler,
});
} catch (err: any) {
return { ok: false, stage: 'bind', error: err };
}
const tunnelPort = boundTunnel.port;
// Point ngrok at the TUNNEL port (not the local port). If this fails,
// tear the listener back down so we don't leak sockets.
try {
const ngrok = await import('@ngrok/ngrok');
const domain = process.env.NGROK_DOMAIN;
const forwardOpts: any = { addr: tunnelPort, authtoken: opts.authtoken };
if (domain) forwardOpts.domain = domain;
// Egress receipt BEFORE the tunnel session opens, fail-closed: a
// writeReceipt failure lands in this catch, which tears the tunnel
// listener back down and refuses the start. One receipt per session
// open; browse command behavior over the tunnel is unchanged.
writeReceipt({
sink: 'browse-tunnel',
host: domain || 'connect.ngrok-agent.com',
payloadClass: 'tunnel-session-open (scoped-token browser-command surface)',
bytes: 0,
sha256: null,
consent: opts.consent,
});
tunnelListener = await ngrok.forward(forwardOpts);
tunnelUrl = tunnelListener.url();
tunnelServer = boundTunnel;
tunnelActive = true;
console.log(`[browse] Tunnel listener bound on 127.0.0.1:${tunnelPort}, ngrok → ${tunnelUrl}`);
// Update state file
const stateContent = JSON.parse(fs.readFileSync(config.stateFile, 'utf-8'));
stateContent.tunnel = { url: tunnelUrl, domain: domain || null, startedAt: new Date().toISOString() };
const tmpState = tmpStatePath();
fs.writeFileSync(tmpState, JSON.stringify(stateContent, null, 2), { mode: 0o600 });
fs.renameSync(tmpState, config.stateFile);
return { ok: true, url: tunnelUrl! };
} catch (err: any) {
// Clean up BOTH ngrok and the Bun listener on failure. If
// ngrok.forward() succeeded but tunnelListener.url() or the
// state-file write threw, we'd otherwise leak an active ngrok
// session on the user's account.
try { if (tunnelListener) await tunnelListener.close(); } catch {}
try { boundTunnel.stop(true); } catch {}
tunnelListener = null;
return { ok: false, stage: 'ngrok', error: err };
}
}
// Module-level validateAuth deleted in v1.35.0.0. Factory-scoped equivalent
// in buildFetchHandler closes over cfg.authToken so every internal auth check
// sees the same token the routes receive.
@ -1310,7 +1385,7 @@ async function handleCommandInternal(
opts?: { skipRateCheck?: boolean; skipActivity?: boolean; chainDepth?: number },
): Promise<CommandResult> {
const cr = await handleCommandInternalImpl(body, tokenInfo, opts);
return { ...cr, result: sanitizeLoneSurrogates(cr.result) };
return { ...cr, result: stripLoneSurrogates(cr.result) };
}
/**
@ -2379,71 +2454,24 @@ export function buildFetchHandler(cfg: ServerConfig): ServerHandle {
}), { status: 400, headers: { 'Content-Type': 'application/json' } });
}
// 2) Bind the tunnel listener on an ephemeral port. HARD FAIL if
// this errors — never fall back to the local port.
let boundTunnel: ReturnType<typeof Bun.serve>;
try {
boundTunnel = Bun.serve({
port: 0,
hostname: '127.0.0.1',
fetch: makeFetchHandler('tunnel'),
});
} catch (err: any) {
// 2) Bind the tunnel listener + open ngrok via the shared helper
// (see startTunnel — hard-fails the bind, cleans up both ngrok
// and the Bun listener on any post-bind failure).
const started = await startTunnel({
fetchHandler: makeFetchHandler('tunnel'),
authtoken,
consent: 'pair_agent=on',
});
if (!started.ok) {
return new Response(JSON.stringify({
error: `Failed to bind tunnel listener: ${err.message}`,
}), { status: 500, headers: { 'Content-Type': 'application/json' } });
}
const tunnelPort = boundTunnel.port;
// 3) Point ngrok at the TUNNEL port (not the local port). If this
// fails, tear the listener back down so we don't leak sockets.
try {
const ngrok = await import('@ngrok/ngrok');
const domain = process.env.NGROK_DOMAIN;
const forwardOpts: any = { addr: tunnelPort, authtoken };
if (domain) forwardOpts.domain = domain;
// Egress receipt BEFORE the tunnel session opens, fail-closed: a
// writeReceipt failure lands in this catch, which tears the tunnel
// listener back down and refuses the start. One receipt per session
// open; browse command behavior over the tunnel is unchanged.
writeReceipt({
sink: 'browse-tunnel',
host: domain || 'connect.ngrok-agent.com',
payloadClass: 'tunnel-session-open (scoped-token browser-command surface)',
bytes: 0,
sha256: null,
consent: 'pair_agent=on',
});
tunnelListener = await ngrok.forward(forwardOpts);
tunnelUrl = tunnelListener.url();
tunnelServer = boundTunnel;
tunnelActive = true;
console.log(`[browse] Tunnel listener bound on 127.0.0.1:${tunnelPort}, ngrok → ${tunnelUrl}`);
// Update state file
const stateContent = JSON.parse(fs.readFileSync(config.stateFile, 'utf-8'));
stateContent.tunnel = { url: tunnelUrl, domain: domain || null, startedAt: new Date().toISOString() };
const tmpState = tmpStatePath();
fs.writeFileSync(tmpState, JSON.stringify(stateContent, null, 2), { mode: 0o600 });
fs.renameSync(tmpState, config.stateFile);
return new Response(JSON.stringify({ url: tunnelUrl }), {
status: 200, headers: { 'Content-Type': 'application/json' },
});
} catch (err: any) {
// Clean up BOTH ngrok and the Bun listener on failure. If
// ngrok.forward() succeeded but tunnelListener.url() or the
// state-file write threw, we'd otherwise leak an active ngrok
// session on the user's account.
try { if (tunnelListener) await tunnelListener.close(); } catch {}
try { boundTunnel.stop(true); } catch {}
tunnelListener = null;
return new Response(JSON.stringify({
error: `Failed to open ngrok tunnel: ${err.message}`,
error: started.stage === 'bind'
? `Failed to bind tunnel listener: ${started.error.message}`
: `Failed to open ngrok tunnel: ${started.error.message}`,
}), { status: 500, headers: { 'Content-Type': 'application/json' } });
}
return new Response(JSON.stringify({ url: started.url }), {
status: 200, headers: { 'Content-Type': 'application/json' },
});
}
// ─── SSE session cookie mint (auth required) ──────────────────
@ -3096,53 +3124,17 @@ export async function start() {
if (!authtoken) {
console.error('[browse] BROWSE_TUNNEL=1 but no NGROK_AUTHTOKEN found. Set it via env var or ~/.gstack/ngrok.env');
} else {
let boundTunnel: ReturnType<typeof Bun.serve> | null = null;
try {
boundTunnel = Bun.serve({
port: 0,
hostname: '127.0.0.1',
fetch: handle.fetchTunnel,
});
const tunnelPort = boundTunnel.port;
const ngrok = await import('@ngrok/ngrok');
const domain = process.env.NGROK_DOMAIN;
const forwardOpts: any = { addr: tunnelPort, authtoken };
if (domain) forwardOpts.domain = domain;
// Egress receipt BEFORE the tunnel session opens, fail-closed: a
// writeReceipt failure lands in this catch, which cleans up the
// listener and skips the tunnel (same as any other startup failure).
writeReceipt({
sink: 'browse-tunnel',
host: domain || 'connect.ngrok-agent.com',
payloadClass: 'tunnel-session-open (scoped-token browser-command surface)',
bytes: 0,
sha256: null,
consent: 'pair_agent=on (BROWSE_TUNNEL=1)',
});
tunnelListener = await ngrok.forward(forwardOpts);
tunnelUrl = tunnelListener.url();
tunnelServer = boundTunnel;
tunnelActive = true;
console.log(`[browse] Tunnel listener bound on 127.0.0.1:${tunnelPort}, ngrok → ${tunnelUrl}`);
// Update state file with tunnel URL
const stateContent = JSON.parse(fs.readFileSync(config.stateFile, 'utf-8'));
stateContent.tunnel = { url: tunnelUrl, domain: domain || null, startedAt: new Date().toISOString() };
const tmpState = tmpStatePath();
fs.writeFileSync(tmpState, JSON.stringify(stateContent, null, 2), { mode: 0o600 });
fs.renameSync(tmpState, config.stateFile);
} catch (err: any) {
console.error(`[browse] Failed to start tunnel: ${err.message}`);
// Same cleanup as /tunnel/start's error path: tear down BOTH
// ngrok and the Bun listener so we don't leak an ngrok session
// if the error happened after ngrok.forward() resolved.
try { if (tunnelListener) await tunnelListener.close(); } catch {}
try { if (boundTunnel) boundTunnel.stop(true); } catch {}
tunnelListener = null;
// Shared startTunnel helper: binds the tunnel listener, opens ngrok,
// and on any failure tears down BOTH ngrok and the Bun listener so we
// don't leak an ngrok session if the error happened after
// ngrok.forward() resolved.
const started = await startTunnel({
fetchHandler: handle.fetchTunnel,
authtoken,
consent: 'pair_agent=on (BROWSE_TUNNEL=1)',
});
if (!started.ok) {
console.error(`[browse] Failed to start tunnel: ${started.error.message}`);
}
}
} else if (process.env.BROWSE_TUNNEL_LOCAL_ONLY === '1') {

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@ -12,18 +12,11 @@
// inherits the invariant — cleanup runs on abort, enqueue failure, AND
// heartbeat failure, exactly once, regardless of which edge fires first.
import { stripLoneSurrogates } from './sanitize';
/**
* JSON.stringify replacer that strips lone UTF-16 surrogates from string
* values before they get escape-encoded. Pair with stringify when the
* consumer will JSON.parse the payload back into JS strings (SSE clients
* do this). Required at every SSE egress that ships page-content-derived
* fields see CLAUDE.md "Unicode sanitization at server egress".
*/
function sanitizeReplacer(_key: string, value: unknown): unknown {
return typeof value === 'string' ? stripLoneSurrogates(value) : value;
}
// sanitizeReplacer strips lone UTF-16 surrogates from string values before
// they get escape-encoded — required at every SSE egress that ships
// page-content-derived fields. See CLAUDE.md "Unicode sanitization at
// server egress" and the canonical implementation in sanitize.ts.
import { sanitizeReplacer } from './sanitize';
/** Send an SSE event. Handles JSON encoding + lone-surrogate sanitization. */
export type SseSender = (event: string, data: unknown) => void;

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@ -140,15 +140,16 @@ describe('Request handler factory', () => {
});
test('Tunnel listener bind uses handle.fetchTunnel from buildFetchHandler', () => {
// v1.35.0.0: factory returns handle.fetchTunnel; tunnel start sites use it
// (BROWSE_TUNNEL=1 startup + BROWSE_TUNNEL_LOCAL_ONLY=1 test path).
// v1.35.0.0: factory returns handle.fetchTunnel; tunnel start sites use it.
// The BROWSE_TUNNEL=1 startup passes it to the shared startTunnel() helper
// (which owns the Bun.serve bind); the BROWSE_TUNNEL_LOCAL_ONLY=1 test path
// binds its own listener with it directly.
// The /tunnel/start handler INSIDE the factory still uses makeFetchHandler('tunnel')
// because it has the local helper in closure scope.
const tunnelOccurrences = SERVER_SRC.match(/fetch: handle\.fetchTunnel/g);
expect(tunnelOccurrences).not.toBeNull();
expect(tunnelOccurrences!.length).toBeGreaterThanOrEqual(2);
expect(SERVER_SRC).toContain('fetchHandler: handle.fetchTunnel');
expect(SERVER_SRC).toContain('fetch: handle.fetchTunnel');
// The factory's internal makeFetchHandler('tunnel') still appears at least
// once for the /tunnel/start route's self-reference + the factory's return.
// once for the /tunnel/start route's startTunnel call + the factory's return.
const internalOccurrences = SERVER_SRC.match(/makeFetchHandler\('tunnel'\)/g);
expect(internalOccurrences).not.toBeNull();
});
@ -244,16 +245,26 @@ describe('Tunnel listener lifecycle', () => {
expect(helperBlock).toContain('tunnelServer.stop');
});
test('/tunnel/start binds the tunnel listener on an ephemeral port', () => {
test('/tunnel/start binds the tunnel listener on an ephemeral port (via startTunnel)', () => {
const startBlock = sliceBetween(
SERVER_SRC,
"url.pathname === '/tunnel/start' && req.method === 'POST'",
"url.pathname === '/refs'"
);
expect(startBlock).toContain('Bun.serve');
expect(startBlock).toContain('port: 0');
// The route delegates to the shared startTunnel() helper, passing the
// factory-scoped tunnel-surface handler.
expect(startBlock).toContain('startTunnel(');
expect(startBlock).toContain("makeFetchHandler('tunnel')");
expect(startBlock).toContain("addr: tunnelPort");
// The helper owns the ephemeral bind and points ngrok at the TUNNEL
// port — never the local daemon port.
const helperBlock = sliceBetween(
SERVER_SRC,
'async function startTunnel(',
'Module-level validateAuth deleted'
);
expect(helperBlock).toContain('Bun.serve');
expect(helperBlock).toContain('port: 0');
expect(helperBlock).toContain("addr: tunnelPort");
});
test('/tunnel/start hard-fails on tunnel listener bind error (no local fallback)', () => {
@ -280,13 +291,22 @@ describe('Tunnel listener lifecycle', () => {
});
test('/tunnel/start tears down tunnel listener when ngrok.forward fails', () => {
// startTunnel owns the error-path teardown: boundTunnel.stop(true) plus
// the ngrok listener close must both run on any post-bind failure, so a
// failed start can't leak sockets or an active ngrok session.
const helperBlock = sliceBetween(
SERVER_SRC,
'async function startTunnel(',
'Module-level validateAuth deleted'
);
expect(helperBlock).toContain('boundTunnel.stop(true)');
expect(helperBlock).toContain('tunnelListener.close()');
// ...and the route maps that failure to the 500 response.
const startBlock = sliceBetween(
SERVER_SRC,
"url.pathname === '/tunnel/start' && req.method === 'POST'",
"url.pathname === '/refs'"
);
// boundTunnel.stop(true) must be called on ngrok error
expect(startBlock).toContain('boundTunnel.stop(true)');
expect(startBlock).toContain('Failed to open ngrok tunnel');
});
@ -296,13 +316,22 @@ describe('Tunnel listener lifecycle', () => {
"process.env.BROWSE_TUNNEL === '1'",
'start().catch'
);
expect(startupBlock).toContain('Bun.serve');
expect(startupBlock).toContain('port: 0');
// v1.35.0.0: start() refactored to use handle.fetchTunnel from the factory.
// The ephemeral-port bind + ngrok forward now live in the shared
// startTunnel() helper the startup path delegates to.
expect(startupBlock).toContain('startTunnel(');
expect(startupBlock).toContain('handle.fetchTunnel');
expect(startupBlock).toContain('addr: tunnelPort');
// Must NOT forward ngrok at the local port
// Must NOT forward ngrok at the local port — neither at the call site
// nor inside the helper, which binds port: 0 and forwards at tunnelPort.
expect(startupBlock).not.toContain('addr: port,');
const helperBlock = sliceBetween(
SERVER_SRC,
'async function startTunnel(',
'Module-level validateAuth deleted'
);
expect(helperBlock).toContain('port: 0');
expect(helperBlock).toContain('addr: tunnelPort');
expect(helperBlock).not.toContain('addr: port,');
});
});

View File

@ -2,23 +2,15 @@ import { describe, test, expect } from 'bun:test';
import * as fs from 'fs';
import * as path from 'path';
// The sanitizer is module-private in server.ts. Rather than refactor it to a
// separate module just for testing, we extract its source via a regex slice and
// eval it in a fresh function scope. Keeps the production layout untouched.
// The sanitizer used to be module-private in server.ts (extracted here via a
// regex slice + eval). It now lives in sanitize.ts as the single source of
// truth for server.ts, sse-helpers.ts, and the read/snapshot pipeline — so
// this suite imports the canonical export and pins the server.ts wiring.
import { stripLoneSurrogates as sanitizeLoneSurrogates } from '../src/sanitize';
const SERVER_PATH = path.resolve(import.meta.dir, '..', 'src', 'server.ts');
const SERVER_SRC = fs.readFileSync(SERVER_PATH, 'utf-8');
const fnMatch = SERVER_SRC.match(
/function sanitizeLoneSurrogates\(str: string\): string \{[\s\S]*?\n\}/
);
if (!fnMatch) throw new Error('Could not locate sanitizeLoneSurrogates in server.ts');
// Strip TS annotations so eval works under plain JS.
const jsSrc = fnMatch[0].replace('(str: string): string', '(str)');
const sanitizeLoneSurrogates = new Function(`${jsSrc}\nreturn sanitizeLoneSurrogates;`)() as (
s: string,
) => string;
describe('sanitizeLoneSurrogates — unit cases', () => {
test('passthrough ASCII', () => {
expect(sanitizeLoneSurrogates('hello')).toBe('hello');
@ -110,7 +102,7 @@ describe('sanitizeLoneSurrogates — wiring invariants', () => {
// refactor moves sanitization back to handleCommand only, this test
// fails by detecting the missing wrapper.
expect(SERVER_SRC).toContain('async function handleCommandInternalImpl(');
expect(SERVER_SRC).toContain('result: sanitizeLoneSurrogates(cr.result)');
expect(SERVER_SRC).toContain('result: stripLoneSurrogates(cr.result)');
});
test('SSE activity feed routes outbound frames through createSseEndpoint', () => {
@ -142,16 +134,31 @@ describe('sanitizeLoneSurrogates — wiring invariants', () => {
const helperSrc = fs.readFileSync(helperPath, 'utf-8');
expect(helperSrc).toContain('JSON.stringify(');
expect(helperSrc).toContain('sanitizeReplacer');
// The sanitizer itself uses stripLoneSurrogates (the shared utility in
// sanitize.ts) — not a private copy. Re-confirms the helper is wired
// to the canonical sanitizer, not a drift'd duplicate.
expect(helperSrc).toContain("import { stripLoneSurrogates } from './sanitize'");
// The replacer is the canonical export from sanitize.ts — not a private
// copy. Re-confirms the helper is wired to the canonical sanitizer, not
// a drift'd duplicate.
expect(helperSrc).toContain("import { sanitizeReplacer } from './sanitize'");
});
test('sanitizeReplacer is a function defined in server.ts (for non-SSE egress)', () => {
// server.ts keeps its own sanitizeReplacer for the non-SSE JSON egress
// paths (handleCommandInternal etc.). The SSE path uses sse-helpers.ts's
// own sanitizeReplacer; both must exist independently.
expect(SERVER_SRC).toContain('function sanitizeReplacer(');
test('sanitizeReplacer is the canonical export wrapping stripLoneSurrogates', () => {
// Single source of truth: sanitize.ts defines the one replacer, and it
// must wrap the shared stripLoneSurrogates (a fast-path rewrite that
// stops sanitizing string values would regress every JSON egress at once).
const sanitizePath = path.resolve(import.meta.dir, '..', 'src', 'sanitize.ts');
const sanitizeSrc = fs.readFileSync(sanitizePath, 'utf-8');
expect(sanitizeSrc).toContain('export function sanitizeReplacer(');
expect(sanitizeSrc).toContain(
"typeof value === 'string' ? stripLoneSurrogates(value) : value",
);
});
test('server.ts imports sanitizeReplacer for non-SSE JSON egress and still uses it', () => {
// server.ts used to define its own private sanitizeReplacer for the
// non-SSE JSON egress paths (/pty-inject-scan, /memory snapshot, etc.).
// It now imports the canonical one — and must still pass it at those
// JSON.stringify egress sites.
expect(SERVER_SRC).toMatch(/import \{[^}]*sanitizeReplacer[^}]*\} from '\.\/sanitize'/);
expect(SERVER_SRC).not.toContain('function sanitizeReplacer(');
expect(SERVER_SRC).toContain(', sanitizeReplacer)');
});
});