fix: Increase maxBuffer for jq processing to handle large Claude outputs (#473)

Fixes "stdout maxBuffer length exceeded" error by increasing the buffer
from Node.js default of 1MB to 10MB when processing Claude output with jq.
This prevents failures when Claude produces large execution logs.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

action.yml

@@ -178,7 +178,7 @@ runs:
         echo "Base-action dependencies installed"
         cd -
         # Install Claude Code globally
-        curl -fsSL https://claude.ai/install.sh | bash -s 1.0.84
+        curl -fsSL https://claude.ai/install.sh | bash -s 1.0.86
         echo "$HOME/.local/bin" >> "$GITHUB_PATH"
 
     - name: Setup Network Restrictions

base-action/action.yml

@@ -118,7 +118,7 @@ runs:
 
     - name: Install Claude Code
       shell: bash
-      run: curl -fsSL https://claude.ai/install.sh | bash -s 1.0.84
+      run: curl -fsSL https://claude.ai/install.sh | bash -s 1.0.86
 
     - name: Run Claude Code Action
       shell: bash

base-action/src/run-claude.ts

@@ -307,7 +307,10 @@ export async function runClaude(promptPath: string, options: ClaudeOptions) {
       await writeFile("output.txt", output);
 
       // Process output.txt into JSON and save to execution file
-      const { stdout: jsonOutput } = await execAsync("jq -s '.' output.txt");
+      // Increase maxBuffer from Node.js default of 1MB to 10MB to handle large Claude outputs
+      const { stdout: jsonOutput } = await execAsync("jq -s '.' output.txt", {
+        maxBuffer: 10 * 1024 * 1024,
+      });
       await writeFile(EXECUTION_FILE, jsonOutput);
 
       console.log(`Log saved to ${EXECUTION_FILE}`);
@@ -324,7 +327,10 @@ export async function runClaude(promptPath: string, options: ClaudeOptions) {
     if (output) {
       try {
         await writeFile("output.txt", output);
-        const { stdout: jsonOutput } = await execAsync("jq -s '.' output.txt");
+        // Increase maxBuffer from Node.js default of 1MB to 10MB to handle large Claude outputs
+        const { stdout: jsonOutput } = await execAsync("jq -s '.' output.txt", {
+          maxBuffer: 10 * 1024 * 1024,
+        });
         await writeFile(EXECUTION_FILE, jsonOutput);
         core.setOutput("execution_file", EXECUTION_FILE);
       } catch (e) {

src/mcp/github-file-ops-server.ts

@@ -3,8 +3,9 @@
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { z } from "zod";
-import { readFile } from "fs/promises";
+import { readFile, stat } from "fs/promises";
 import { join } from "path";
+import { constants } from "fs";
 import fetch from "node-fetch";
 import { GITHUB_API_URL } from "../github/api/config";
 import { retryWithBackoff } from "../utils/retry";
@@ -162,6 +163,34 @@ async function getOrCreateBranchRef(
   return baseSha;
 }
 
+// Get the appropriate Git file mode for a file
+async function getFileMode(filePath: string): Promise<string> {
+  try {
+    const fileStat = await stat(filePath);
+    if (fileStat.isFile()) {
+      // Check if execute bit is set for user
+      if (fileStat.mode & constants.S_IXUSR) {
+        return "100755"; // Executable file
+      } else {
+        return "100644"; // Regular file
+      }
+    } else if (fileStat.isDirectory()) {
+      return "040000"; // Directory (tree)
+    } else if (fileStat.isSymbolicLink()) {
+      return "120000"; // Symbolic link
+    } else {
+      // Fallback for unknown file types
+      return "100644";
+    }
+  } catch (error) {
+    // If we can't stat the file, default to regular file
+    console.warn(
+      `Could not determine file mode for ${filePath}, using default: ${error}`,
+    );
+    return "100644";
+  }
+}
+
 // Commit files tool
 server.tool(
   "commit_files",
@@ -223,6 +252,9 @@ server.tool(
             ? filePath
             : join(REPO_DIR, filePath);
 
+          // Get the proper file mode based on file permissions
+          const fileMode = await getFileMode(fullPath);
+
           // Check if file is binary (images, etc.)
           const isBinaryFile =
             /\.(png|jpg|jpeg|gif|webp|ico|pdf|zip|tar|gz|exe|bin|woff|woff2|ttf|eot)$/i.test(
@@ -261,7 +293,7 @@ server.tool(
             // Return tree entry with blob SHA
             return {
               path: filePath,
-              mode: "100644",
+              mode: fileMode,
               type: "blob",
               sha: blobData.sha,
             };
@@ -270,7 +302,7 @@ server.tool(
             const content = await readFile(fullPath, "utf-8");
             return {
               path: filePath,
-              mode: "100644",
+              mode: fileMode,
               type: "blob",
               content: content,
             };