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grunt-jsonlint

Validate JSON files from grunt.

grunt-jsonlint

Validate JSON files from grunt.

Requires grunt 1.0+ and node 4.0+.

Install

npm install grunt-jsonlint --save-dev

Configure

Add the following (multi-)task to your Gruntfile:

jsonlint: {
  sample: {
    src: [ 'some/valid.json' ],
    options: {
      formatter: 'prose'
    }
  }
}

Add the following to load the task into your Gruntfile:

grunt.loadNpmTasks('grunt-jsonlint');

An error will be thrown if the JSON file contains syntax errors. To prefer an error format compatible with Visual Studio, change the formatter to 'msbuild'.

Here's a simple tutorial on how to use grunt-jsonlint

Formatting

Add the following (multi-)task to your Gruntfile:

jsonlint: {
  all: {
    src: [ 'some/valid.json' ],
    options: {
      format: true,
      indent: 2,
    }
  }
}
  • format, when true JSON.stringify will be used to format the JavaScript (if it is valid)
  • indent, the value passed to JSON.stringify, it can be the number of spaces, or string like "\t"

Reporting

There are a few options available for reporting errors:

The standard error message format (prose) is optimized for human reading and looks like:

>> File "test/invalid.json" failed JSON validation at line 9.

This is customizable to conform to the Visual Studio style by specifying the formatter option as msbuild, like:

jsonlint: {

  visualStudioExample: {
    src: [ 'test/invalid.json' ],
    options: {
      formatter: 'msbuild'
    }
  }

}

The output will look like:

>> test/invalid.json(9): error: failed JSON validation

By default, the raw error from the underlying jsonlint library comes through to the grunt output. It looks like:

Error: Parse error on line 9:
...        "2"        "3",      ],      
----------------------^
Expecting 'EOF', '}', ':', ',', ']', got 'STRING'

To customize this, change the reporter option to jshint (the format is inspired by how jshint formats their output, hence the name):

jsonlint: {

  jshintStyle: {
    src: [ 'test/invalid.json' ],
    options: {
      reporter: 'jshint'
    }
  }

}

The output will look like:

 9 |     "3"
         ^ Expected 'EOF', '}', ':', ',', ']' and instead saw '3'

The default reporter is called exception since it simply relays the raw exception.

Roadmap

The underlying jsonlint library has many features not yet exposed. Each of these would be valuable in grunt.

  • Schema validation
  • Sort file by key

Running tests

Unit tests are provided for automated regression testing. The easiest way to run them is with

$ npm install
$ npm test

Alternatively, if you have grunt-cli installed, you could use grunt directly with

$ npm install
$ grunt test

Which does the same thing.

Release History

  • 2013-02-20 v1.0.0 First official release
  • 2013-09-19 v1.0.1 Do not log every validated file
  • 2013-10-31 v1.0.2 Add output of count of successfully linted JSON file for issue
  • 2013-11-16 v1.0.3 Fix output of count of successfully linted JSON files.
  • 2013-11-18 v1.0.4 Updated for latest dependencies.
  • 2015-10-11 v1.0.5 Updated for latest dependencies.
  • 2015-10-29 v1.0.6 CJSON support thanks to @fredghosn, unit tests
  • 2015-12-23 v1.0.7 Include file name and JSON source line number in error messages
  • 2016-05-27 v1.0.8 Option to format JSON file thanks to @robblue2x
  • 2016-06-11 v1.1.0 Enhanced error reporting for better human reading and Visual Studio integration.