fix: resolve WASM file loading issue for npx execution (closes #31)

- Enhanced database adapter to support multiple WASM file resolution strategies
- Added require.resolve() for reliable package location in npm environments
- Made better-sqlite3 an optional dependency
- Improved error handling with clear messages
- Updated version to 2.7.13
- Updated CHANGELOG and README badges

scripts/publish-npm.sh

@@ -64,6 +64,7 @@ pkg.license = 'MIT';
 pkg.bugs = { url: 'https://github.com/czlonkowski/n8n-mcp/issues' };
 pkg.homepage = 'https://github.com/czlonkowski/n8n-mcp#readme';
 pkg.files = ['dist/**/*', 'data/nodes.db', '.env.example', 'README.md', 'LICENSE'];
+// Note: node_modules are automatically included for dependencies
 delete pkg.private; // Remove private field so we can publish
 require('fs').writeFileSync('./package.json', JSON.stringify(pkg, null, 2));
 "

scripts/test-database-adapter.js

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+
+const { createDatabaseAdapter } = require('../dist/database/database-adapter');
+const path = require('path');
+
+async function testDatabaseAdapter() {
+  console.log('Testing database adapter initialization...\n');
+  
+  const dbPath = path.join(__dirname, '../data/nodes.db');
+  console.log('Database path:', dbPath);
+  
+  try {
+    console.log('Creating database adapter...');
+    const adapter = await createDatabaseAdapter(dbPath);
+    
+    console.log('\n✅ Database adapter created successfully!');
+    
+    // Test a simple query
+    console.log('\nTesting database query...');
+    const stmt = adapter.prepare('SELECT COUNT(*) as count FROM nodes');
+    const result = stmt.get();
+    console.log(`✅ Database contains ${result.count} nodes`);
+    
+    // Check FTS5 support
+    console.log('\nChecking FTS5 support...');
+    const hasFTS5 = adapter.checkFTS5Support();
+    console.log(`FTS5 support: ${hasFTS5 ? '✅ Available' : '❌ Not available'}`);
+    
+    adapter.close();
+    console.log('\n✅ All tests passed!');
+  } catch (error) {
+    console.error('\n❌ Error:', error.message);
+    console.error('Stack:', error.stack);
+    process.exit(1);
+  }
+}
+
+testDatabaseAdapter();

scripts/test-sqljs-fallback.js

@@ -0,0 +1,43 @@
+#!/usr/bin/env node
+
+// Force sql.js usage by temporarily hiding better-sqlite3
+const Module = require('module');
+const originalRequire = Module.prototype.require;
+
+Module.prototype.require = function(id) {
+  if (id === 'better-sqlite3') {
+    throw new Error('Simulating better-sqlite3 not available (NODE_MODULE_VERSION mismatch)');
+  }
+  return originalRequire.apply(this, arguments);
+};
+
+const { createDatabaseAdapter } = require('../dist/database/database-adapter');
+const path = require('path');
+
+async function testSqlJsFallback() {
+  console.log('Testing sql.js fallback...\n');
+  
+  const dbPath = path.join(__dirname, '../data/nodes.db');
+  
+  try {
+    console.log('Creating database adapter (better-sqlite3 disabled)...');
+    const adapter = await createDatabaseAdapter(dbPath);
+    
+    console.log('\n✅ Database adapter created successfully with sql.js!');
+    
+    // Test a simple query
+    console.log('\nTesting database query...');
+    const stmt = adapter.prepare('SELECT COUNT(*) as count FROM nodes');
+    const result = stmt.get();
+    console.log(`✅ Database contains ${result.count} nodes`);
+    
+    adapter.close();
+    console.log('\n✅ sql.js fallback works correctly!');
+  } catch (error) {
+    console.error('\n❌ Error:', error.message);
+    console.error('Stack:', error.stack);
+    process.exit(1);
+  }
+}
+
+testSqlJsFallback();

scripts/test-wasm-resolution.js

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+
+const path = require('path');
+const fs = require('fs');
+
+console.log('Testing WASM file resolution...\n');
+
+// Show current environment
+console.log('Current directory:', process.cwd());
+console.log('Script directory:', __dirname);
+console.log('Node version:', process.version);
+console.log('');
+
+// Test different path resolutions
+const testPaths = [
+  // Local development path
+  path.join(__dirname, '../node_modules/sql.js/dist/sql-wasm.wasm'),
+  // When installed as npm package
+  path.join(__dirname, '../../sql.js/dist/sql-wasm.wasm'),
+  // Alternative npm package path
+  path.join(process.cwd(), 'node_modules/sql.js/dist/sql-wasm.wasm'),
+];
+
+console.log('Checking potential WASM file locations:');
+testPaths.forEach((testPath, index) => {
+  const exists = fs.existsSync(testPath);
+  console.log(`${index + 1}. ${testPath}`);
+  console.log(`   Exists: ${exists ? '✅' : '❌'}`);
+});
+
+// Try require.resolve
+console.log('\nTrying require.resolve:');
+try {
+  const wasmPath = require.resolve('sql.js/dist/sql-wasm.wasm');
+  console.log('✅ Found via require.resolve:', wasmPath);
+  console.log('   Exists:', fs.existsSync(wasmPath) ? '✅' : '❌');
+} catch (e) {
+  console.log('❌ Failed to resolve via require.resolve:', e.message);
+}
+
+// Try to find sql.js package location
+console.log('\nTrying to find sql.js package:');
+try {
+  const sqlJsPath = require.resolve('sql.js');
+  console.log('✅ Found sql.js at:', sqlJsPath);
+  const sqlJsDir = path.dirname(sqlJsPath);
+  const wasmFromSqlJs = path.join(sqlJsDir, '../dist/sql-wasm.wasm');
+  console.log('   Derived WASM path:', wasmFromSqlJs);
+  console.log('   Exists:', fs.existsSync(wasmFromSqlJs) ? '✅' : '❌');
+} catch (e) {
+  console.log('❌ Failed to find sql.js package:', e.message);
+}