n8n-MCP

"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); exports.ExpressionValidator = void 0; class ExpressionValidator { static validateExpression(expression, context) { const result = { valid: true, errors: [], warnings: [], usedVariables: new Set(), usedNodes: new Set(), }; if (!expression) { return result; } if (!context) { result.valid = false; result.errors.push('Validation context is required'); return result; } const syntaxErrors = this.checkSyntaxErrors(expression); result.errors.push(...syntaxErrors); const expressions = this.extractExpressions(expression); for (const expr of expressions) { this.validateSingleExpression(expr, context, result); } this.checkNodeReferences(result, context); result.valid = result.errors.length === 0; return result; } static checkSyntaxErrors(expression) { const errors = []; const openBrackets = (expression.match(/\{\{/g) || []).length; const closeBrackets = (expression.match(/\}\}/g) || []).length; if (openBrackets !== closeBrackets) { errors.push('Unmatched expression brackets {{ }}'); } const nestedPattern = /\{\{[^}]*\{\{/; if (nestedPattern.test(expression)) { errors.push('Nested expressions are not supported (expression inside another expression)'); } const emptyExpressionPattern = /\{\{\s*\}\}/; if (emptyExpressionPattern.test(expression)) { errors.push('Empty expression found'); } return errors; } static extractExpressions(text) { const expressions = []; let match; while ((match = this.EXPRESSION_PATTERN.exec(text)) !== null) { expressions.push(match[1].trim()); } return expressions; } static validateSingleExpression(expr, context, result) { let match; const jsonPattern = new RegExp(this.VARIABLE_PATTERNS.json.source, this.VARIABLE_PATTERNS.json.flags); while ((match = jsonPattern.exec(expr)) !== null) { result.usedVariables.add('$json'); if (!context.hasInputData && !context.isInLoop) { result.warnings.push('Using $json but node might not have input data'); } const fullMatch = match[0]; if (fullMatch.includes('.invalid') || fullMatch.includes('.undefined') || fullMatch.includes('.null') || fullMatch.includes('.test')) { result.warnings.push(`Property access '${fullMatch}' looks suspicious - verify this property exists in your data`); } } const nodePattern = new RegExp(this.VARIABLE_PATTERNS.node.source, this.VARIABLE_PATTERNS.node.flags); while ((match = nodePattern.exec(expr)) !== null) { const nodeName = match[1]; result.usedNodes.add(nodeName); result.usedVariables.add('$node'); } const inputPattern = new RegExp(this.VARIABLE_PATTERNS.input.source, this.VARIABLE_PATTERNS.input.flags); while ((match = inputPattern.exec(expr)) !== null) { result.usedVariables.add('$input'); if (!context.hasInputData) { result.warnings.push('$input is only available when the node has input data'); } } const itemsPattern = new RegExp(this.VARIABLE_PATTERNS.items.source, this.VARIABLE_PATTERNS.items.flags); while ((match = itemsPattern.exec(expr)) !== null) { const nodeName = match[1]; result.usedNodes.add(nodeName); result.usedVariables.add('$items'); } for (const [varName, pattern] of Object.entries(this.VARIABLE_PATTERNS)) { if (['json', 'node', 'input', 'items'].includes(varName)) continue; const testPattern = new RegExp(pattern.source, pattern.flags); if (testPattern.test(expr)) { result.usedVariables.add(`$${varName}`); } } this.checkCommonMistakes(expr, result); } static checkCommonMistakes(expr, result) { const missingPrefixPattern = /(?<![.$\w['])\b(json|node|input|items|workflow|execution)\b(?!\s*[:''])/; if (expr.match(missingPrefixPattern)) { result.warnings.push('Possible missing $ prefix for variable (e.g., use $json instead of json)'); } if (expr.includes('$json[') && !expr.match(/\$json\[\d+\]/)) { result.warnings.push('Array access should use numeric index: $json[0] or property access: $json.property'); } if (expr.match(/\$json\['[^']+'\]/)) { result.warnings.push("Consider using dot notation: $json.property instead of $json['property']"); } if (expr.match(/\?\./)) { result.warnings.push('Optional chaining (?.) is not supported in n8n expressions'); } if (expr.includes('${')) { result.errors.push('Template literals ${} are not supported. Use string concatenation instead'); } } static checkNodeReferences(result, context) { for (const nodeName of result.usedNodes) { if (!context.availableNodes.includes(nodeName)) { result.errors.push(`Referenced node "${nodeName}" not found in workflow`); } } } static validateNodeExpressions(parameters, context) { const combinedResult = { valid: true, errors: [], warnings: [], usedVariables: new Set(), usedNodes: new Set(), }; const visited = new WeakSet(); this.validateParametersRecursive(parameters, context, combinedResult, '', visited); combinedResult.valid = combinedResult.errors.length === 0; return combinedResult; } static validateParametersRecursive(obj, context, result, path = '', visited = new WeakSet()) { if (obj && typeof obj === 'object') { if (visited.has(obj)) { return; } visited.add(obj); } if (typeof obj === 'string') { if (obj.includes('{{')) { const validation = this.validateExpression(obj, context); validation.errors.forEach(error => { result.errors.push(path ? `${path}: ${error}` : error); }); validation.warnings.forEach(warning => { result.warnings.push(path ? `${path}: ${warning}` : warning); }); validation.usedVariables.forEach(v => result.usedVariables.add(v)); validation.usedNodes.forEach(n => result.usedNodes.add(n)); } } else if (Array.isArray(obj)) { obj.forEach((item, index) => { this.validateParametersRecursive(item, context, result, `${path}[${index}]`, visited); }); } else if (obj && typeof obj === 'object') { Object.entries(obj).forEach(([key, value]) => { const newPath = path ? `${path}.${key}` : key; this.validateParametersRecursive(value, context, result, newPath, visited); }); } } } exports.ExpressionValidator = ExpressionValidator; ExpressionValidator.EXPRESSION_PATTERN = /\{\{([\s\S]+?)\}\}/g; ExpressionValidator.VARIABLE_PATTERNS = { json: /\$json(\.[a-zA-Z_][\w]*|\["[^"]+"\]|\['[^']+'\]|\[\d+\])*/g, node: /\$node\["([^"]+)"\]\.json/g, input: /\$input\.item(\.[a-zA-Z_][\w]*|\["[^"]+"\]|\['[^']+'\]|\[\d+\])*/g, items: /\$items\("([^"]+)"(?:,\s*(-?\d+))?\)/g, parameter: /\$parameter\["([^"]+)"\]/g, env: /\$env\.([a-zA-Z_][\w]*)/g, workflow: /\$workflow\.(id|name|active)/g, execution: /\$execution\.(id|mode|resumeUrl)/g, prevNode: /\$prevNode\.(name|outputIndex|runIndex)/g, itemIndex: /\$itemIndex/g, runIndex: /\$runIndex/g, now: /\$now/g, today: /\$today/g, }; //# sourceMappingURL=expression-validator.js.map