JSON Assertion to check format of JSON in Jmeter - json

Question

I am using Jmeter for the first time and have response data as follows:
{"types":[{"type":"tag","probability":"0.94"},{"type":"word","probability":"0.03"},{"type":"search","probability":"0.01"},{"type":"model","probability":"0.0"},{"type":"express","probability":"0.0"},{"type":"serial","probability":"0.0"}],"suggestions":[{"model":"AXT","dist":0.4286},{"model":"XL","dist":0.4},{"model":"03H","dist":0.4},{"model":"03","dist":0.4},{"model":"1435","dist":0.375}]}
I am trying to validate with regex if the JSON has specific format that to have type and probability under types and model and dist under suggestions.
I used following but it does not validate
$.types[*].type

Answer 1

I don't think JSON Assertion is the good way to proceed, maybe it worth considering asking for a JSON Schema and validating the response using JSR223 Assertion and Groovy language?
If you don't have the schema you can generate it from your JSON using online tools like this one, it gives me something like:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"properties": {
"types": {
"type": "array",
"items": [
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
},
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
},
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
},
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
},
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
},
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"probability": {
"type": "string"
}
},
"required": [
"type",
"probability"
]
}
]
},
"suggestions": {
"type": "array",
"items": [
{
"type": "object",
"properties": {
"model": {
"type": "string"
},
"dist": {
"type": "number"
}
},
"required": [
"model",
"dist"
]
},
{
"type": "object",
"properties": {
"model": {
"type": "string"
},
"dist": {
"type": "number"
}
},
"required": [
"model",
"dist"
]
},
{
"type": "object",
"properties": {
"model": {
"type": "string"
},
"dist": {
"type": "number"
}
},
"required": [
"model",
"dist"
]
},
{
"type": "object",
"properties": {
"model": {
"type": "string"
},
"dist": {
"type": "number"
}
},
"required": [
"model",
"dist"
]
},
{
"type": "object",
"properties": {
"model": {
"type": "string"
},
"dist": {
"type": "number"
}
},
"required": [
"model",
"dist"
]
}
]
}
},
"required": [
"types",
"suggestions"
]
}
The above schema has been auto-generated from your JSON file, you might need to amend it according to your requirements.
So you can:
Save the schema to your hard drive next to the .jmx script
Add the following libraries to JMeter Classpath
commons-digester-1.8.1.jar
commons-validator-1.6.jar
everit-json-schema-1.14.0.jar
handy-uri-templates-2.1.8.jar
joda-time-2.10.2.jar
json-20201115.jar
re2j-1.3.jar
Add JSR223 Assertion as a child of the request which returns the above response
Put the following code into "Script" area
def schema = org.everit.json.schema.loader.SchemaLoader.load(new org.json.JSONObject(new File('schema.json')))
try {
schema.validate(new org.json.JSONObject(prev.getResponseDataAsString()))
}
catch (Exception ex) {
AssertionResult.setFailure(true)
AssertionResult.setFailureMessage(ex.getMessage())
}
If the response will not match schema - the assertion will fail the sampler.
More information:
Introduction to JSON Schema in Java
JSON Schema Validator