Zie619/n8n-workflows · error · Error

Invalid quantity Requested: ${quantityRequested}. Must be gr

Q: What causes "Invalid quantity Requested: ${quantityRequested}. Must be greater than 0" in Zie619/n8n-workflows?

Parse first, then validate: use Number.isFinite and > 0 so both garbage and non-positive values are caught.

Error message

Invalid quantity Requested: ${quantityRequested}. Must be greater than 0

What it means

Thrown by 'Validate Issue Request Data' when `Quantity Requested` from the issue-request webhook is <= 0. The check runs on the raw input (no parsing), so undefined also compares <= 0 in JS (undefined <= 0 is false - actually undefined converts to NaN, so NaN <= 0 is false; but '0', empty string '', and 0 all pass the throw). Empty string '' <= 0 is true, so blank submissions throw here.

Source

Thrown at workflows/Code/0926_Code_Webhook_Create_Webhook.json:1591

      "parameters": {
        "sendTo": "example@gmail.com",
        "message": "=<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"UTF-8\">\n  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n  <title>Low Stock Alert</title>\n  <style>\n    body {\n      font-family: Arial, sans-serif;\n      line-height: 1.6;\n      color: #333;\n      background-color: #f4f4f4;\n      margin: 0;\n      padding: 0;\n    }\n    .container {\n      width: 80%;\n      max-width: 600px;\n      margin: 20px auto;\n      background-color: #fff;\n      padding: 20px;\n      border-radius: 8px;\n      box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);\n    }\n    h2 {\n      color: #e74c3c;\n      text-align: center;\n    }\n    p {\n      margin: 10px 0;\n    }\n    .alert-message {\n      background-color: #ffe6e6;\n      padding: 15px;\n      border-left: 4px solid #e74c3c;\n      margin: 20px 0;\n      font-weight: bold;\n    }\n    ul {\n      list-style-type: none;\n      padding: 0;\n      margin: 20px 0;\n      background-color: #f9f9f9;\n      padding: 15px;\n      border-left: 4px solid #3498db;\n    }\n    ul li {\n      margin: 8px 0;\n    }\n    ul li strong {\n      display: inline-block;\n      width: 150px;\n    }\n    .action {\n      text-align: center;\n      margin: 20px 0;\n    }\n    .btn {\n      display: inline-block;\n      padding: 10px 20px;\n      text-decoration: none;\n      color: #fff;\n      background-color: #3498db;\n      border-radius: 5px;\n      font-weight: bold;\n    }\n    .footer {\n      text-align: center;\n      margin-top: 20px;\n      font-size: 0.9em;\n      color: #777;\n    }\n  </style>\n</head>\n<body>\n  <div class=\"container\">\n    <h2>Low Stock Alert</h2>\n    <p>Dear Stock Manager,</p>\n\n    <p>We have detected a low stock level for the following material:</p>\n\n    <div class=\"alert-message\">\n      {{ $json[\"Alert Message\"] }}\n    </div>\n\n    <ul>\n      <li><strong>Product ID:</strong> {{ $json[\"Product ID\"] }}</li>\n      <li><strong>Material:</strong> {{ $json[\"Material Name\"] }}</li>\n      <li><strong>Current Stock:</strong> {{ $json[\"Current Stock\"] }} {{ $json[\"Measurement Unit\"] }}</li>\n      <li><strong>Minimum Stock:</strong> {{ $json[\"Minimum Stock Level\"] }} {{ $json[\"Measurement Unit\"] }}</li>\n    </ul>\n\n    <div class=\"action\">\n      <p>Please take action to reorder this material.</p>\n      <a href=\"{{ $env.WEBHOOK_URL }}\" class=\"btn\">Reorder Now</a>\n    </div>\n\n    <div class=\"footer\">\n      <p>Regards,<br>Your Company</p>\n    </div>\n  </div>\n</body>\n</html>",
        "options": {},
        "subject": "Low Stock Alert: Immediate Action Required"
      },
      "typeVersion": 2.1,
      "notes": "This gmail node performs automated tasks as part of the workflow."
    },
    {
      "id": "ac8781e9-f694-467d-b40b-95bdbab98880",
      "name": "Validate Issue Request Data",
      "type": "n8n-nodes-base.code",
      "position": [
        6340,
        3400
      ],
      "parameters": {
        "jsCode": "const input = $input.all()[0].json;\nconst quantityRequested= input[\"Quantity Requested\"];\n\nif (quantityRequested <= 0) throw new Error(`Invalid quantity Requested: ${quantityRequested}. Must be greater than 0`);\n\nreturn { json: input };"
      },
      "typeVersion": 2,
      "notes": "This code node performs automated tasks as part of the workflow."
    },
    {
      "id": "6d88db70-6b4f-47c5-8093-ab339762edbe",
      "name": "Verify Requested Quantity",
      "type": "n8n-nodes-base.code",
      "position": [
        6560,
        3400
      ],
      "parameters": {
        "jsCode": "const input = $input.all()[0].json;\nconst quantityRequested = input[\"Quantity Requested\"];\nif (!input[\"Product ID\"]) throw new Error(\"Product ID is missing\");\nif (quantityRequested <= 0) throw new Error(`Invalid quantity requested: ${quantityRequested}`);\nif (!input[\"Submission ID\"]) throw new Error(\"Submission ID is missing\");\nreturn { json: input };"
      },
      "typeVersion": 2,
      "notes": "This code node performs automated tasks as part of the workflow."
    },

View on GitHub (pinned to 94007c1445)

Solutions

Parse first, then validate: use Number.isFinite and > 0 so both garbage and non-positive values are caught.
Enforce min=1 and required on the quantity field in the request form.
Include the raw value and its type in the error for diagnosis.
Route failures to an error-response branch that tells the requester instead of failing silently.

Example fix

// before
const quantityRequested = input["Quantity Requested"];
if (quantityRequested <= 0) throw new Error(`Invalid quantity Requested: ${quantityRequested}. Must be greater than 0`);

// after
const quantityRequested = Number(input["Quantity Requested"]);
if (!Number.isFinite(quantityRequested) || quantityRequested <= 0) {
  throw new Error(`Invalid quantity Requested: ${JSON.stringify(input["Quantity Requested"])}. Must be a number greater than 0`);
}

Defensive patterns

Strategy: validation

Validate before calling

const quantityRequested = Number(input['Quantity Requested']);
if (!Number.isFinite(quantityRequested) || quantityRequested <= 0) {
  throw new Error(`Invalid quantity Requested: ${JSON.stringify(input['Quantity Requested'])}. Must be greater than 0`);
}

Type guard

const isValidRequestedQty = (v) => {
  const n = Number(v);
  return Number.isFinite(n) && n > 0;
};

Prevention

Convert to Number before comparing - raw '<= 0' lets NaN slip through
Set min=1 and required on the request form
Echo the raw value (JSON.stringify) in the error
Route invalid submissions to a user-facing error response branch

When it happens

Trigger: Submission with Quantity Requested = 0, '0', or '' (empty string); a -1 test value; input.readOnly draft submissions; type coercion surprises: '5abc' is NaN so it does NOT throw here and fails later.

Common situations: Request form allows 0 or blank quantity; form validation missing client-side; numeric field submitted as text with empty value.

Related errors

AI-assisted analysis of Zie619/n8n-workflows@94007c1445 (2026-08-15). Data as JSON: /api/errors/014c8e233e3f49c4. Report an issue: GitHub.