JSONPath Match Assertion

Applies to ReadyAPI 3.51, last modified on March 04, 2024

The JSONPath Match assertion uses a JSONPath expression to select content from the target property and compare the result to the value you expect. The assertion passes if they are matching, otherwise it fails.

This assertion applies only to requests and responses, bodies of which contain JSON data.

To learn more about the JSONPath syntax, see JSONPath Reference.

Availability

This assertion is available in multiple ReadyAPI applications. Depending on the application, it validates the following data:

In... Checks... To learn more...
Functional tests The request or response body. See Working With Assertions in Functional Tests.
Security tests The response body. See Security Assertions.
Virtual services The request body. See Assertions in Virtual Services.

Create an assertion

Follow these steps:

Functional test: The Assertions panel

Click the image to enlarge it.

  1. Open a test step.

  2. Click Add assertion.

In the New Assertions dialog, search for the JSONPath Match assertion or select it manually in the Property Content category.

Follow these steps:

Security tests: The Assertions panel

Click the image to enlarge it.

  1. Open a security test.

  2. Click Response Assertion next to any scan.

  3. Click in the Assertions panel

In the New Assertions dialog, search for the JSONPath Match assertion or select it manually in the Property Content category.

Follow these steps:

Virtual service: The Assertions panel

Click the image to enlarge it.

  1. Open a virtual service.

  2. Open the Assertions drop-down panel.

  3. Click in the Assertions panel

In the New Assertions dialog, search for the JSONPath Match assertion or select it manually in the Property Content category.

Setting up properties

  1. In the JSONPath Expression edit box, specify the JSONPath expression to point at the element you want to compare the result with, or use the toolbar controls to create the expression automatically.

    To use the toolbar controls, run the request you want to validate at least once.
    ReadyAPI: Configuring the JSONPath Match assertion

    Click the image to enlarge it.

    Click Select node to call the Select JSON dialog. Use it to select a node from the last request or response and create a JSON path expression for this node.

  2. In the Expected Result edit box, specify the value you are expecting to get. Use the property expansion to point at a specific node.

    Use these commands to visually select the value from the existing request or response:

    Option Description
    Select Content Add a property expansion in the result.
    Select from Current Get a value from the last response you have received (or the last request the virtual service has received).

    When possible, ReadyAPI converts JSON values to objects of the corresponding type (integer, boolean and so on) and compares them. Otherwise, ReadyAPI treats values as strings.

    To command ReadyAPI to compare values as strings, enclose the expected value in quotes. If a string contains quotes, you need to specify a backslash (\) before each of them. For example:

    "First Name \"Nickname\" Last Name"
  3. To command the assertion to use an asterisk wildcard (*) for varying parts of the value, select Allow Wildcards.

    Note: If you do not select this option, the assertion will fail on dynamic values.
  4. To test your assertion on the last response you have received (or the last request the virtual service has received), click Test.

  • If the specified JSONPath expression refers to a non-existing JSON node, its value equals an empty string. So, if you leave an empty string in the Expected Result field, the assertion will pass.

  • It is also possible to specify a property expansion that refers a non-existing property in the Expected Result field. Its value will be an empty string as well. So, if you specify a JSONPath expression that refers to a non-existing node, and a property expansion that refers to a non-existing property as the expected result, the assertion will pass.

Tips
  • To avoid typing the desired JSONPath expression manually, click Select node and select the desired JSON element or attribute in the subsequent dialog.

    ReadyAPI: Selecting an element for JSONPath expression

    ReadyAPI will form the JSONPath expression that refers the selected item, and will set the result from the last request or response as the expected result.

  • ASP.NET-based services enclose the JSON response payload into the d root element for security reasons. By default, ReadyAPI does not strip the d element out, but there is an option to automatically remove it. If you turn this option on, JSON-related assertions created from the JSON response will not take the root element into account, which can cause the assertion to fail unexpectedly.

Notes on Syntax
  • The assertion ignores the excessive spaces and line breaks within JSON expressions. Use any type of markup you find suitable. For example, the following code:

    {"test": ["value1", "value2", "value3"], "test2": true}

    is treated as identical to this one:

    {
      "test": ["value1", "value2", "value3"],
      "test2": true
    }
  • JSONPath expressions can return either a single value or an array, depending on the expression syntax:

    • Expression containing filters ([?(filter)] and array slices ([start:end] always returns arrays, even if the resulting array contains a single item. For example:

      $.section.fields.item[?(@.name=='My Field')].fldValue

      – will return an array even if the fldValue element has one value only. To get this value, add an index to the expression:

      $.section.fields.item[?(@.name=='My Field')].fldValue[0]

    • Object wildcards will return an array only if the object has 2 or more properties. Otherwise, these will return a value of the single property (this value will keep the initial type). For example, assume that you need to obtain properties of the following object:

      {
        "section": {
          "first_subsection": {
            "name": "titular"
          },
          "second_subsection": {
            "name": "secondary",
            "contains_images": true
          }
        }
      }

      The following expression will return a titular string:

      $.section.first_subsection.*

      // The first_subsection element has a single property

      The following expression will return an array:

      $.section.second_subsection.*

      // Returns ["name": "secondary", "contains_images": true"]

    • The behavior of the array wildcards (arr[*]) depends on which ReadyAPI version you use:

      • In ReadyAPI 2.3.0 and later: Array wildcards should always return an array. For the preceding example, the following expression:

        $.section.first_subsection[*]

        – will return an array:

        ["name": "titular"]

      • In ReadyAPI 1.9.0 – 2.2.0: Array wildcards return an array only if the original array includes more than 2 items. For the arrays including a single item, the results vary depending on the item type.

        For example, for the following objects:

        {
          "section": ["content"],
          "second_section": [ {"number": 2} ]
        }

        the JSONPath expressions will work as follows:

        $.section[*] = content // A string $.second_section[*] = [ {"number": 2} ] // An array

  • The following JSONPath expression gets all text subelements in the widget element:

    $.widget.text
  • The following JSONPath expression gets all subelements in the widget element:

    $.widget.*
  • The following JSONPath expression gets all text subelements of the header type in the widget element:

    $.widget.text[?(@.type=='header')]
  • The following JSONPath expression gets the element with index 4 from the tags array:

    $.widget.tags[4]
  • The following JSONPath expression gets the entire tags array:

    $.widget.tags

See Also

Property Content Assertions
JSONPath Existence Match Assertion
JSONPath Count Assertion
JSONPath RegEx Match Assertion
JSONPath Reference

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