If you're seeing the error:
INVALID_PROPERTY_VALUE
A numerical value is expected to follow the negative sign.
Here’s the quick fix:
Ensure a valid number follows the minus (-) sign in your expression.
The expression in your If condition must not include misplaced operators or incomplete syntax.
What's Going Wrong?
In this payload:
{
"type": "If",
"condition": "${data.val} ) -a",
"then": [...]
}
There are multiple issues:
${data.val} ) has a mismatched closing parenthesis.
-a is not a valid number or operand. The minus sign expects a number like -5 or a proper subtraction expression like ${data.val} - 2.
How to Fix It
Clean up the expression to make it syntactically valid. Here's a corrected version assuming you want to check if data.val is greater than -1:
{
"type": "If",
"condition": "${data.val} > -1",
"then": [...]
}
Or if you're comparing against another variable:
{
"type": "If",
"condition": "${data.val} - ${data.anotherVal} > 0",
"then": [...]
}
Developer Tips
Always wrap dynamic values with ${...}.
Every operator (+, -, >, etc.) must have valid operands on both sides.
Watch for extra parentheses or misplaced characters—these are common sources of parsing errors.
Use tools or formatters to spot broken expressions early.
TL;DR
The minus sign must be followed by a valid number or a complete subtraction.
-a: Invalid
-1, ${data.val} - 2: Valid