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Test-Json

Modulo:
Microsoft.PowerShell.Utility Module

Tests whether a string is a valid JSON document

Sintassi

__AllParameterSets (impostazione predefinita). 

Test-Json
    [-Json] <String>
    [<CommonParameters>]

SchemaString 

Test-Json
    [-Json] <String>
    [[-Schema] <String>]
    [<CommonParameters>]

SchemaFile 

Test-Json
    [-Json] <String>
    [-SchemaFile <String>]
    [<CommonParameters>]

Descrizione

The Test-Json cmdlet tests whether a string is a valid JavaScript Object Notation (JSON) document and can optionally verify that JSON document against a provided schema.

The verified string can then be used with the ConvertFrom-Json cmdlet convert a JSON-formatted string to a JSON object, which is easily managed in PowerShell or sent to another program or web service that access JSON input.

Many web sites use JSON instead of XML to serialize data for communication between servers and web-based apps.

This cmdlet was introduced in PowerShell 6.1

Esempio

Example 1: Test if an object is valid JSON

This example tests whether the input string is a valid JSON document.

'{"name": "Ashley", "age": 25}' | Test-Json

True

Example 2: Test an object against a provided schema

This example takes a string containing a JSON schema and compares it to an input string.

$schema = @'
{
  "definitions": {},
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "http://example.com/root.json",
  "type": "object",
  "title": "The Root Schema",
  "required": [
    "name",
    "age"
  ],
  "properties": {
    "name": {
      "$id": "#/properties/name",
      "type": "string",
      "title": "The Name Schema",
      "default": "",
      "examples": [
        "Ashley"
      ],
      "pattern": "^(.*)$"
    },
    "age": {
      "$id": "#/properties/age",
      "type": "integer",
      "title": "The Age Schema",
      "default": 0,
      "examples": [
        25
      ]
    }
  }
}
'@
'{"name": "Ashley", "age": "25"}' | Test-Json -Schema $schema

Test-Json:
Line |
  35 |  '{"name": "Ashley", "age": "25"}' | Test-Json -Schema $schema
     |                                      ~~~~~~~~~~~~~~~~~~~~~~~~~
     | IntegerExpected: #/age
False

In this example, we get an error because the schema expects an integer for age but the JSON input we tested uses a string value instead.

For more information, see JSON Schema.

Example 3: Test an object against a schema from file

JSON schema can reference definitions using $ref keyword. The $ref can resolve to a URI that references another file. The SchemaFile parameter accepts literal path to the JSON schema file and allows JSON files to be validated against such schemas.

In this example the schema.json file references definitions.json.

Get-Content schema.json

{
  "description":"A person",
  "type":"object",
  "properties":{
    "name":{
      "$ref":"definitions.json#/definitions/name"
    },
    "hobbies":{
      "$ref":"definitions.json#/definitions/hobbies"
    }
  }
}

Get-Content definitions.json

{
  "definitions":{
    "name":{
      "type":"string"
    },
    "hobbies":{
      "type":"array",
      "items":{
        "type":"string"
      }
    }
  }
}

'{"name": "James", "hobbies": [".NET", "Blogging"]}' | Test-Json -SchemaFile 'schema.json'

True

For more information, see Structuring a complex schema.

Parametri

-Json

Specifies the JSON string to test for validity. Enter a variable that contains the string, or type a command or expression that gets the string. You can also pipe a string to Test-Json.

The Json parameter is required.

Proprietà dei parametri

Tipo:String
Valore predefinito:None
Supporta i caratteri jolly:False
DontShow:False

Set di parametri

(All)
Posizione:1
Obbligatorio:True
Valore dalla pipeline:True
Valore dalla pipeline in base al nome della proprietà:False
Valore dagli argomenti rimanenti:False

-Schema

Specifies a schema to validate the JSON input against. If passed, Test-Json validates that the JSON input conforms to the spec specified by the Schema parameter and return $true only if the input conforms to the provided schema.

For more information, see JSON Schema.

Proprietà dei parametri

Tipo:String
Valore predefinito:None
Supporta i caratteri jolly:False
DontShow:False

Set di parametri

SchemaString
Posizione:2
Obbligatorio:False
Valore dalla pipeline:False
Valore dalla pipeline in base al nome della proprietà:False
Valore dagli argomenti rimanenti:False

-SchemaFile

Specifies a schema file used to validate the JSON input. When used, the Test-Json returns $true only if the JSON input conforms to the schema defined in the file specified by the SchemaFile parameter.

For more information, see JSON Schema.

Proprietà dei parametri

Tipo:String
Valore predefinito:None
Supporta i caratteri jolly:False
DontShow:False

Set di parametri

SchemaFile
Posizione:Named
Obbligatorio:False
Valore dalla pipeline:False
Valore dalla pipeline in base al nome della proprietà:False
Valore dagli argomenti rimanenti:False

CommonParameters

This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutBuffer, -OutVariable, -PipelineVariable, -ProgressAction, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters.

Input

String

You can pipe a JSON string to this cmdlet.

Output

Boolean

This cmdlet returns $true if the JSON is valid and otherwise $false.

Note

The Test-Json cmdlet is implemented using the NJsonSchema Class.

Since PowerShell 6, PowerShell uses the Newtonsoft.Json assemblies for all JSON functions. Newtonsoft's implementation includes several extensions to the JSON standard, such as support for comments and use of single quotes. For a full list of features, see the Newtonsoft documentation at https://www.newtonsoft.com/json.