Assertions

An assertion is a check that Nouto runs against the response every time you send a request. Each assertion compares one part of the response, such as the status code or a JSONPath value, with an expected value. Results appear in the request editor, the response panel, and the Collection Runner. For checks that need code, use scripts.

Add an assertion

1. Open a request and select the Tests tab. For a gRPC request, select the Assertions tab.
2. Click Add Test. Nouto adds a row that checks Status Code = 200. For a gRPC request, the new row checks Status Code = 0.
3. Choose the target, operator, and expected value.
4. Send the request.

The tab label shows the number of assertions, for example Tests (3).

Each row has these fields:

Field	Description
Checkbox	Turns the assertion on or off without deleting it
Target	The part of the response to check
Property	A JSONPath expression, header name, or similar input. Shown only for targets that need one.
Operator	How to compare the value with the expected value. Hidden for JSON Schema and Set Variable.
Expected	The value to compare against. Hidden for operators that don’t use one.

To delete a row, click its Remove assertion button.

Targets

Target	Property	Value checked
Status Code	None	HTTP status code
Response Time	None	Response time in milliseconds
Response Size	None	Response body size in bytes
Response Body	None	The whole body as text
JSON Path	JSONPath expression, for example $.data[0].name	The matched value. When the path matches more than one value, Nouto compares them as a JSON array.
Header	Header name, case-insensitive	The value of that response header
Content-Type	None	The value of the Content-Type header
JSON Schema	None	Validates the JSON body against a schema that you paste into the text area below the row
Set Variable	JSONPath expression	Saves a value to a variable. See Save a response value.

gRPC targets

For gRPC requests, the Header target is labeled Header / Initial Metadata, and four more targets are available:

Target	Property	Value checked
gRPC Status Name	None	Status code name, for example OK, NOT_FOUND, or UNAVAILABLE
gRPC Trailer	Trailer name, case-insensitive	The value of that response trailer
Stream Msg Count	None	Number of messages received in a streaming call
Stream Message	0 for the first message, or 0.$.field for a field in it	One message by its zero-based index, or a JSONPath value inside it. A message that isn’t JSON is compared as text.

Operators

The operator list shows these labels:

Operator	Passes when
=	The value equals the expected value. When both are numbers, Nouto compares them as numbers, so 200 equals 200.0. Otherwise the text must match exactly.
!=	The value doesn’t equal the expected value
contains	The value contains the expected text. Case-sensitive.
!contains	The value doesn’t contain the expected text, or the value is missing
>, <, >=, <=	The numeric comparison holds. Fails when either side isn’t a number.
exists	The target has a value. Takes no expected value.
!exists	The target has no value. Takes no expected value.
isType	The value’s JSON type matches the expected type: string, number, boolean, array, object, or null. A string that looks like a number, such as "42", counts as number.
isJSON	The value parses as JSON. Takes no expected value.
count	The array length, or the number of keys in an object, equals the expected number
regex	The value matches the expected JavaScript regular expression. Enter the pattern without slashes or flags.
any[] =	At least one array item equals the expected text
any[] contains	At least one array item contains the expected text
any[] starts	At least one array item starts with the expected text
any[] ends	At least one array item ends with the expected text

The any[] operators treat a value that isn’t an array as an array with one item.

Save a response value

The Set Variable target copies a value from the JSON response into a variable, so later requests can use it.

1. Select Set Variable as the target.
2. In Property, enter the JSONPath of the value, for example $.token.
3. In Variable name, enter the variable to set, for example authToken.

When the response arrives, Nouto saves the first value that the path matches to the active environment. The row passes when Nouto finds a value. It fails, with Could not extract value for variable, when the path matches nothing.

Caution

Select an active environment before you rely on Set Variable. Without one, Nouto discards the value.

Later requests read the value as {{authToken}}, for example in an Authorization: Bearer {{authToken}} header. In the Collection Runner, the value is available to the requests that run after this one.

Collection and folder assertions

To check every request in a collection or folder, right-click it in the sidebar, select Settings…, open the Tests tab, and click Add Assertion. Nouto runs these assertions together with each request’s own assertions.

Results

In the request editor, each row shows a pass or fail icon after the response arrives. A failed row shows the failure message and the actual value after Got:. The Test Assertions header shows a count such as 3/5 passed.

The response panel adds a Tests tab, labeled with the count, for example Tests 3/5. It shows a summary such as 3/5 tests passed (2 failed), followed by each assertion’s message and, for failures, the actual value.

In the Collection Runner, the Result column shows the passed and total assertion count next to Pass or Fail. Click a row to see each assertion.

Examples

These examples show one assertion per table row.

Check the status and response time:

Target	Property	Operator	Expected
Status Code		=	200
Response Time		<	500

Check that a JSON field exists and has the right type:

Target	Property	Operator	Expected
JSON Path	$.data	exists
JSON Path	$.data.users	isType	array
JSON Path	$.data.total	>	0

Check a gRPC streaming call:

Target	Property	Operator	Expected
gRPC Status Name		=	OK
Stream Msg Count		>=	3
Stream Message	0.$.id	exists

Saving and exporting

Nouto saves assertions with the request in its collection. To keep them when you share a collection, export it as a Nouto collection. Postman exports don’t include assertions.