Interface Test Framework Practice (4) | Get Schema Assertion

JSON Schema introduction and installation

JSON Schema is a format for describing the structure of JSON data, and a JSON Schema schema is a vocabulary.Through JSON Schema, you can annotate JSON fields and field data types and other information.

In actual work, the assertion check is performed on the interface return value. In addition to the assertion detection of common fields, the types of other fields are also checked.It is obviously very time-consuming to write assertions to the returned fields one by one. At this time, a template is needed to define the data type and matching conditions. Except for the key parameters, the rest can be directly asserted through this template. Json Schema can be perfectly implemented.such demand.By verifying the JSON Schema, you can determine whether the Response conforms to the contract.

A JSON-formatted data, usually composed of one or more of the following data types:

1. string
2. Numeric(integer, number)
3. object
4. array
5. boolean
6. null

The above 6 data types in JSON Schema have corresponding attributes to describe them.

Json Schema official website: http://json-schema.org/implementations.html 8

Environmental preparation

Install the JSON Schema package:

pip install jsonschema

Use of JSON Schema

JsonSchema template generation

1. First, use the Json Schema Tool website:

https://www.jsonschema.net/ 11

Copy the returned JSON string to the left side of the page, then click INFER SHCEMA, it will be automatically converted to the Schema JSON file type, and the return value type of each field will be set to a default type; you can also write regular patterns in the patternto match:

json11080×720 64.3 KB

1. Click the "Settings" button to display more detailed assertion settings for each type of return value. This is the most common and practical function of Schema, and it can also verify or assert the most detailed interval value for each type of field., such as length, value range, etc.

1. Click the Copy button to save the generated Schema template.

json31080×265 21.7 KB

JSON Schema verification case

The following is an example of JSON Schema, which only has two important fields name and price.This schema specifies that name must be of type string and price must be of type number.Use JSON Schema for validation, use the validate method, and enter a data whose name is Eggs and price is 34.99 for validation:

def test_schema(self):schema = {"type": "object","properties": {"price": {"type": "number"},"name": {"type":"string"},},}validate(instance={"name": "Eggs", "price": 34.99},schema=schema)

If the number is written as a string, an error will occur:

>>> from jsonschema import validate>>> schema = {... "type": "object",... "properties": {... "price": {"type": "string"},... "name": {"type":"string"},... },... }>>> validate(instance={"name": "Eggs", "price": 34.99},schema=schema)

Return error message:

Traceback (most recent call last):File "", line 1, in File "/Users/lixu/Library/Python/3.7/lib/python/site-packages/jsonschema/validators.py",\line 934, in validateraise errorjsonschema.exceptions.ValidationError: 34.99 is not of type 'string'

Above, JSON Schema, as a data verification tool for interface testing, makes the work more efficient, and also better implements interface monitoring, so that you can know where there is a problem and correct it in time.More will be discussed in subsequent chapters.