From f5de77d4ca67e238de186f50e9652a6cd155966c Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Mon, 13 Apr 2026 18:19:40 +0000
Subject: [PATCH] Fix echo >> append redirect being parsed as > redirect

The >> operator in echo commands was being incorrectly parsed because
the > regex matched first, capturing "> file" as the redirect target
instead of appending to "file". Fix by checking >> before > and adding
a negative lookahead to the > pattern so it doesn't match >>.

Fixes pixari/gitvana#43

https://claude.ai/code/session_01HoJy5MNq1ePZXgubLzWm8x
---
 src/lib/engine/shell/builtins.ts | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/lib/engine/shell/builtins.ts b/src/lib/engine/shell/builtins.ts
index c0f9992..d49b611 100644
--- a/src/lib/engine/shell/builtins.ts
+++ b/src/lib/engine/shell/builtins.ts
@@ -160,21 +160,7 @@ async function echoCommand(args: string[], fs: FsLike, cwd: string): Promise<Bui
   const escapeFlag = raw.startsWith('-e ');
   const content_raw = escapeFlag ? raw.slice(3) : raw;
 
-  // Handle redirect: echo [-e] "content" > file
-  const redirectMatch = content_raw.match(/^(.*?)\s*>\s*(.+)$/);
-  if (redirectMatch) {
-    let content = redirectMatch[1].replace(/^["']|["']$/g, '');
-    if (escapeFlag) content = interpretEscapes(content);
-    const filepath = resolvePath(redirectMatch[2].trim(), cwd);
-    try {
-      await fs.promises.writeFile(filepath, content + '\n');
-      return { output: '', success: true };
-    } catch {
-      return { output: `echo: cannot write to '${redirectMatch[2]}'`, success: false };
-    }
-  }
-
-  // Handle append: echo [-e] "content" >> file
+  // Handle append: echo [-e] "content" >> file (must check before > to avoid >> being parsed as >)
   const appendMatch = content_raw.match(/^(.*?)\s*>>\s*(.+)$/);
   if (appendMatch) {
     let content = appendMatch[1].replace(/^["']|["']$/g, '');
@@ -189,6 +175,20 @@ async function echoCommand(args: string[], fs: FsLike, cwd: string): Promise<Bui
     }
   }
 
+  // Handle redirect: echo [-e] "content" > file
+  const redirectMatch = content_raw.match(/^(.*?)\s*>(?!>)\s*(.+)$/);
+  if (redirectMatch) {
+    let content = redirectMatch[1].replace(/^["']|["']$/g, '');
+    if (escapeFlag) content = interpretEscapes(content);
+    const filepath = resolvePath(redirectMatch[2].trim(), cwd);
+    try {
+      await fs.promises.writeFile(filepath, content + '\n');
+      return { output: '', success: true };
+    } catch {
+      return { output: `echo: cannot write to '${redirectMatch[2]}'`, success: false };
+    }
+  }
+
   let output = content_raw.replace(/^["']|["']$/g, '');
   if (escapeFlag) output = interpretEscapes(output);
   return { output, success: true };