Kotlin function error handling
If the handler reports a Kotlin function execution or loading error, the runtime automatically catches the error and returns a JSON document with information about the error type. For more information about the JSON document format, see Calling a function. Error details are written to the execution log.
Examples of error handling
Let's assume the handler returns the sum of numbers. An empty request will cause the handler to throw IllegalArgumentException.
Function code:
fun handle(request: IntArray): Int {
if (request.isEmpty()) throw IllegalArgumentException()
return request.sum()
}
Case 1. When invoking a function, the user provides the [1, 22, 333] array:
curl \
--header "Authorization: Bearer <IAM_token>" \
--data "[1, 22, 333]" \
"https://functions.yandexcloud.net/<function_ID>?integration=raw"
The function returns 356, the sum of the numbers.
Case 2. The user provides an empty array:
curl \
--header "Authorization: Bearer <IAM_token>" \
--data "[]" \
"https://functions.yandexcloud.net/<function_ID>?integration=raw"
The runtime catches the exception and generates a JSON document containing the error message (the errorMessage field), error type (the errorType field), and stack trace (the stackTrace field).
JSON document returned:
{
"errorMessage": "An exception has occurred in the user code, details: java.lang.IllegalArgumentException. [ERR_USER_CODE]",
"errorType": "IllegalArgumentException",
"stackTrace": [
{
"function": "handle",
"file": "Handler.kt",
"line": 2
},
...
]
}
Case 3. The user provides a string instead of numbers, which results in a deserialization error:
curl \
--header "Authorization: Bearer <IAM_token>" \
--data "notanarray" \
"https://functions.yandexcloud.net/<function_ID>?integration=raw"
JSON document returned:
{
"errorMessage": "An exception has occurred during request deserialization. Details: com.squareup.moshi.JsonEncodingException: Use JsonReader.setLenient(true) to accept malformed JSON at path $. [ERR_INVALID_REQUEST]",
"errorType": "FunctionException"
}