From bdc4818bf5942bfea2c9c3992d66c0fdf03152d2 Mon Sep 17 00:00:00 2001
From: Garry Tan <garrytan@gmail.com>
Date: Fri, 1 May 2026 07:36:59 -0700
Subject: [PATCH] fix(harness): anchor extractPlanFilePath path captures on
 /Users|~|/home|/var|/tmp
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Adversarial-tightened gate sweep surfaced a real bug in the path
extraction: stripAnsi collapses whitespace via cursor-positioning escape
removal, so "yet at /Users/..." in the visible buffer becomes
"yetat/Users/..." with no space between. The previous fallback pattern
`(~?\/?\S*\.claude\/plans\/[\w-]+\.md)` greedily matched non-whitespace
characters BEFORE the path, producing `yetat/Users/garrytan/.claude/...`
which then fails fs.readFileSync.

Fix: every regex now requires the path to START at a known path-anchor:
`~/`, `/Users/`, `/home/`, `/var/`, `/tmp/`, or `./`. Earlier
non-whitespace runs can't be glommed in.

Verified against the failing fixture (`yetat/Users/...`) plus the four
canonical render forms ("Plan saved to:", "Plan file:", `·`-decorated
ctrl-g hint, and the bare fallback).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 test/helpers/claude-pty-runner.ts | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/test/helpers/claude-pty-runner.ts b/test/helpers/claude-pty-runner.ts
index d3602b12..58a17b51 100644
--- a/test/helpers/claude-pty-runner.ts
+++ b/test/helpers/claude-pty-runner.ts
@@ -183,21 +183,24 @@ export function isAutoDecidedVisible(visible: string): boolean {
  */
 export function extractPlanFilePath(visible: string): string | null {
   // Patterns checked in order of specificity. Each captures the .md path.
-  // The visible buffer may have stripAnsi-collapsed whitespace, so we
-  // accept space-or-not separators in the prompts and accept paths
-  // without intervening whitespace (e.g. `editinVSCode·~/.claude/...`).
+  // The visible buffer may have stripAnsi-collapsed whitespace ("yet at" can
+  // become "yetat"), so the captured path MUST start at a clear path-anchor
+  // character: `~/`, `/Users/`, `/home/`, `/var/`, or `/tmp/`. Anchoring on
+  // these prefixes prevents earlier non-whitespace characters from being
+  // glommed into the path (real bug seen in the wild: `yetat/Users/...`).
+  const PATH_ANCHOR = '(~\\/|\\/Users\\/|\\/home\\/|\\/var\\/|\\/tmp\\/|\\.\\/)';
   const patterns: RegExp[] = [
-    /Plan\s*saved\s*to\s*:?\s*(\S+\.md)/i,
-    /Plan\s*file\s*:?\s*(\S+\.md)/i,
-    /·\s*(\S+\.claude\/plans\/\S+\.md)/i,
-    // Fallback: any reference to a .claude/plans path in the buffer.
-    /(~?\/?\S*\.claude\/plans\/[\w-]+\.md)/i,
+    new RegExp(`Plan\\s*saved\\s*to\\s*:?\\s*(${PATH_ANCHOR}\\S+\\.md)`, 'i'),
+    new RegExp(`Plan\\s*file\\s*:?\\s*(${PATH_ANCHOR}\\S+\\.md)`, 'i'),
+    new RegExp(`·\\s*(${PATH_ANCHOR}\\S*\\.claude\\/plans\\/\\S+\\.md)`, 'i'),
+    // Fallback: any path-anchored reference to a .claude/plans .md file.
+    new RegExp(`(${PATH_ANCHOR}\\S*\\.claude\\/plans\\/[\\w-]+\\.md)`, 'i'),
   ];
   for (const p of patterns) {
     const m = visible.match(p);
     if (m && m[1]) {
       let raw = m[1];
-      // Some patterns capture trailing punctuation; strip a trailing dot.
+      // Strip trailing punctuation that some patterns may capture.
       raw = raw.replace(/\.+$/, '.md').replace(/\.md\.+$/, '.md');
       // Tilde expansion to absolute path.
       if (raw.startsWith('~')) {