How to use the command Test-Json (with examples)
The Test-Json command is used to test whether a string is a valid JSON document. It is a command available only in PowerShell and can be used to check if a given string or file is formatted as valid JSON.
Use case 1: Testing if a string from stdin is in JSON format
Code:
'string' | Test-Json
Motivation:
Imagine you have a script that takes user input and you want to ensure that the provided input is in JSON format. By using the Test-Json command with input from stdin, you can quickly validate if the input is a valid JSON document.
Explanation:
In this use case, the command 'string' | Test-Json checks if the provided string is a valid JSON document. The input string should be replaced with the actual string you want to test. The | symbol is used to pipe the string as input to the Test-Json command.
Example output:
If the provided string is in JSON format, the command will return True. Otherwise, it will return False.
Use case 2: Testing if a string is in JSON format
Code:
Test-Json -Json 'json_to_test'
Motivation:
Sometimes, you may have a specific string that you want to validate as a JSON document. By using the Test-Json command with the -Json parameter, you can directly provide the string to test.
Explanation:
In this use case, the command Test-Json -Json 'json_to_test' checks if the specified string 'json_to_test' is a valid JSON document. Replace 'json_to_test' with the actual string you want to test.
Example output:
If the provided string is in JSON format, the command will return True. Otherwise, it will return False.
Use case 3: Testing if a string from stdin matches a specific schema file
Code:
'string' | Test-Json -SchemaFile path\to\schema_file.json
Motivation:
When working with JSON documents, it is common to have a schema file that defines the structure and constraints for the JSON data. By using the Test-Json command with the -SchemaFile parameter, you can validate if a given string from stdin matches the specified schema file.
Explanation:
In this use case, the command 'string' | Test-Json -SchemaFile path\to\schema_file.json checks if the provided string is a valid JSON document and matches the specified schema file. Replace 'string' with the actual string you want to test and path\to\schema_file.json with the path to the schema file you want to use.
Example output:
If the provided string is in JSON format and matches the schema file, the command will return True. Otherwise, it will return False.
Conclusion:
The Test-Json command is a useful tool for validating JSON documents in PowerShell. Whether you want to check if a string is in JSON format, specifically test a string, or validate against a schema file, this command provides a convenient way to ensure the validity of JSON data.
