From 3cb75d46bf6ee0a44d846a4d3e2cc3196e9ba418 Mon Sep 17 00:00:00 2001
From: gensokyo-dev <gensokyo-dev@users.noreply.github.com>
Date: Fri, 13 Nov 2026 16:52:21 +0000
Subject: [PATCH] test(mcp): guard portable pattern escapes in every schema
 profile

The advertised-pattern guard only inspected the default profile and only
rejected the `\0` and `\u0000` NUL spellings, so a `\uD800` range shipped
in 6.9.0 unnoticed. Reject any unescaped `\u` or `\0` escape, and run that
check for each input and output schema profile.

Co-Authored-By: gensokyo-dev <gensokyo-dev@users.noreply.github.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../mcp/advertisedPatternsVMode.test.ts       | 60 +++++++++++++++----
 1 file changed, 49 insertions(+), 11 deletions(-)

diff --git a/tests/boundary/mcp/advertisedPatternsVMode.test.ts b/tests/boundary/mcp/advertisedPatternsVMode.test.ts
index 1291d79d9a..022b43d673 100644
--- a/tests/boundary/mcp/advertisedPatternsVMode.test.ts
+++ b/tests/boundary/mcp/advertisedPatternsVMode.test.ts
@@ -64,11 +64,16 @@ const collectPatterns = (
   }
 };
 
-it("advertises portable NUL escapes and patterns that compile in all JS modes", async () => {
+const listAdvertisedTools = async (
+  environment?: Readonly<NodeJS.ProcessEnv>,
+) => {
   const session = createTestBinarySession(() => {
     throw new Error("No deep provider may start for a schema projection");
   });
-  const server = createServer({ kind: "session", session });
+  const server = createServer(
+    { kind: "session", session },
+    environment === undefined ? {} : { environment },
+  );
   const client = new Client({ name: "advertised-patterns", version: "1" });
   onTestFinished(async () => {
     await client.close();
@@ -79,8 +84,20 @@ it("advertises portable NUL escapes and patterns that compile in all JS modes",
     InMemoryTransport.createLinkedPair();
   await server.connect(serverTransport);
   await client.connect(clientTransport);
+  return (await client.listTools()).tools;
+};
 
-  const advertised = (await client.listTools()).tools;
+// A `\u` or `\0` escape that is not itself escaped. RE2 has no `\u` escape,
+// Rust refuses `\u` surrogate ranges, and DeepSeek rejects the short NUL escape
+// even though V8 accepts all of them; any one refuses the complete tools
+// request. Unlike the compile checks above, this guard covers every profile.
+const NON_PORTABLE_ESCAPE = /(?:^|[^\\])(?:\\\\)*\\[0u]/u;
+
+const nonPortableEscapes = (patterns: readonly AdvertisedPattern[]) =>
+  patterns.filter(({ pattern }) => NON_PORTABLE_ESCAPE.test(pattern));
+
+it("advertises portable NUL escapes and patterns that compile in all JS modes", async () => {
+  const advertised = await listAdvertisedTools();
   const patterns: AdvertisedPattern[] = [];
   const canonicalBase64Leaves: Record<string, unknown>[] = [];
   for (const tool of advertised) {
@@ -129,14 +146,9 @@ it("advertises portable NUL escapes and patterns that compile in all JS modes",
     patterns.filter(({ pattern }) => /\(\?<?[=!]|\\[1-9]|\\k</u.test(pattern)),
   ).toEqual([]);
 
-  // DeepSeek rejects the short NUL escape even though V8 accepts it in all
-  // three modes. Keep the shared hex spelling across the advertised catalog;
-  // actual provider acceptance is verified separately from JS compilation.
-  expect(
-    patterns.filter(
-      ({ pattern }) => pattern.includes("\\0") || pattern.includes("\\u0000"),
-    ),
-  ).toEqual([]);
+  // Keep the shared hex NUL spelling across the advertised catalog; actual
+  // provider acceptance is verified separately from JS compilation.
+  expect(nonPortableEscapes(patterns)).toEqual([]);
   expect(patterns.some(({ pattern }) => pattern.includes("\\x00"))).toBe(true);
 
   expect(canonicalBase64Leaves.length).toBeGreaterThan(0);
@@ -154,3 +166,29 @@ it("advertises portable NUL escapes and patterns that compile in all JS modes",
       ),
     );
 });
+
+it.each(
+  (["compact", "full"] as const).flatMap((input) =>
+    (["full", "compact", "off"] as const).map((output) => [input, output]),
+  ),
+)(
+  "advertises portable escapes for %s input and %s output schemas",
+  async (input, output) => {
+    const advertised = await listAdvertisedTools({
+      ...process.env,
+      REA_MCP_INPUT_SCHEMA_PROFILE: input,
+      REA_MCP_OUTPUT_SCHEMA_PROFILE: output,
+    });
+    const patterns: AdvertisedPattern[] = [];
+    for (const tool of advertised) {
+      collectPatterns(tool.inputSchema, "inputSchema", tool.name, patterns);
+      if (tool.outputSchema !== undefined)
+        collectPatterns(tool.outputSchema, "outputSchema", tool.name, patterns);
+    }
+    // Every profile carries local path inputs, so the guard is not vacuous.
+    expect(patterns.some(({ pattern }) => pattern.includes("\\x00"))).toBe(
+      true,
+    );
+    expect(nonPortableEscapes(patterns)).toEqual([]);
+  },
+);