feat(mcp): Implement update-subtask MCP command for appending information to subtasks

mcp-server/src/core/direct-functions/update-subtask-by-id.js

@@ -0,0 +1,107 @@
+/**
+ * update-subtask-by-id.js
+ * Direct function implementation for appending information to a specific subtask
+ */
+
+import { updateSubtaskById } from '../../../../scripts/modules/task-manager.js';
+import { findTasksJsonPath } from '../utils/path-utils.js';
+
+/**
+ * Direct function wrapper for updateSubtaskById with error handling.
+ * 
+ * @param {Object} args - Command arguments containing id, prompt, useResearch and file path options.
+ * @param {Object} log - Logger object.
+ * @returns {Promise<Object>} - Result object with success status and data/error information.
+ */
+export async function updateSubtaskByIdDirect(args, log) {
+  try {
+    log.info(`Updating subtask with args: ${JSON.stringify(args)}`);
+    
+    // Check required parameters
+    if (!args.id) {
+      const errorMessage = 'No subtask ID specified. Please provide a subtask ID to update.';
+      log.error(errorMessage);
+      return { 
+        success: false, 
+        error: { code: 'MISSING_SUBTASK_ID', message: errorMessage },
+        fromCache: false 
+      };
+    }
+    
+    if (!args.prompt) {
+      const errorMessage = 'No prompt specified. Please provide a prompt with information to add to the subtask.';
+      log.error(errorMessage);
+      return { 
+        success: false, 
+        error: { code: 'MISSING_PROMPT', message: errorMessage },
+        fromCache: false 
+      };
+    }
+    
+    // Validate subtask ID format
+    const subtaskId = args.id;
+    if (typeof subtaskId !== 'string' || !subtaskId.includes('.')) {
+      const errorMessage = `Invalid subtask ID format: ${subtaskId}. Subtask ID must be in format "parentId.subtaskId" (e.g., "5.2").`;
+      log.error(errorMessage);
+      return { 
+        success: false, 
+        error: { code: 'INVALID_SUBTASK_ID_FORMAT', message: errorMessage },
+        fromCache: false 
+      };
+    }
+    
+    // Get tasks file path
+    let tasksPath;
+    try {
+      tasksPath = findTasksJsonPath(args, log);
+    } catch (error) {
+      log.error(`Error finding tasks file: ${error.message}`);
+      return { 
+        success: false, 
+        error: { code: 'TASKS_FILE_ERROR', message: error.message },
+        fromCache: false 
+      };
+    }
+    
+    // Get research flag
+    const useResearch = args.research === true;
+    
+    log.info(`Updating subtask with ID ${subtaskId} with prompt "${args.prompt}" and research: ${useResearch}`);
+    
+    // Execute core updateSubtaskById function
+    const updatedSubtask = await updateSubtaskById(tasksPath, subtaskId, args.prompt, useResearch);
+    
+    // Handle the case where the subtask couldn't be updated (e.g., already marked as done)
+    if (!updatedSubtask) {
+      return {
+        success: false,
+        error: { 
+          code: 'SUBTASK_UPDATE_FAILED', 
+          message: 'Failed to update subtask. It may be marked as completed, or another error occurred.' 
+        },
+        fromCache: false
+      };
+    }
+    
+    // Return the updated subtask information
+    return {
+      success: true,
+      data: {
+        message: `Successfully updated subtask with ID ${subtaskId}`,
+        subtaskId,
+        parentId: subtaskId.split('.')[0],
+        subtask: updatedSubtask,
+        tasksPath,
+        useResearch
+      },
+      fromCache: false // This operation always modifies state and should never be cached
+    };
+  } catch (error) {
+    log.error(`Error updating subtask by ID: ${error.message}`);
+    return { 
+      success: false, 
+      error: { code: 'UPDATE_SUBTASK_ERROR', message: error.message || 'Unknown error updating subtask' },
+      fromCache: false 
+    };
+  }
+} 

mcp-server/src/core/task-master-core.js

@@ -10,6 +10,7 @@ import { getCacheStatsDirect } from './direct-functions/cache-stats.js';
 import { parsePRDDirect } from './direct-functions/parse-prd.js';
 import { updateTasksDirect } from './direct-functions/update-tasks.js';
 import { updateTaskByIdDirect } from './direct-functions/update-task-by-id.js';
+import { updateSubtaskByIdDirect } from './direct-functions/update-subtask-by-id.js';
 
 // Re-export utility functions
 export { findTasksJsonPath } from './utils/path-utils.js';
@@ -21,6 +22,7 @@ export {
   parsePRDDirect,
   updateTasksDirect,
   updateTaskByIdDirect,
+  updateSubtaskByIdDirect,
 };
 
 /**
@@ -33,5 +35,6 @@ export const directFunctions = {
   parsePRD: parsePRDDirect,
   update: updateTasksDirect,
   updateTask: updateTaskByIdDirect,
+  updateSubtask: updateSubtaskByIdDirect,
   // Add more functions as we implement them
 };