find-duplicated-property-keys

find-duplicated-property-keys

A package for detecting all duplicated property keys of a JSON string. It can either be used as a standalone tool for validating JSON files or as a submodule for other Node.js projects.

Use as a Standlone Tool

If you like to use find-duplicated-property-keys as a standalone tool, you first have to install it by using the following command:

$ npm install find-duplicated-property-keys

To run this tool you simply need to execute it from the installation directory like this:

$ node_modules/.bin/find-duplicated-property-keys -s <path-to-json-file>

Of course, if you prefer a more comfortable way of running this tool, you can also install it globally by using this command:

$ npm install -g find-duplicated-property-keys

Then you can run find-duplicated-property-keys from any directory by using the following command:

$ find-duplicated-property-keys -s <path-to-json-file>

When running the tool from terminal, it will list all duplicated property keys followed by the number of their occurrence or return a notification to indicate the JSON file does not contain any duplicated property keys. In addition to that, find-duplicated-property-keys will then also return one of the following exit codes:

Exit Code	Description
0	The passed JSON file has been analyzed succesfully and no duplicated property keys have been detected. Note, this exit code will also be returned, if the help text has been requested by either running find-duplicated-property-keys without any parameters or with the parameter --help or its alias -h solely.
1	An exception has been thrown by the tool and the validation process was unable to determine a result.
101	The passed JSON file has been analyzed succesfully and at least one duplicated property key has been detected.

Use as a Submodule

In case you need to include find-duplicated-property-keys into another project, you first have to add it to your Node.js application by executing the following command while being in the root directory of your project:

$ npm install find-duplicated-property-keys

To validate a JSON string you can run the module as described in the following example:

const findDuplicatedPropertyKeys = require('find-duplicated-property-keys');

const jsonString = '{"name": "Carl", "name": "Carla", "age": 29}';

const result = findDuplicatedPropertyKeys(jsonString);

console.log(result.toString()); // <instance>.name

The returned result will be an array that contains all duplicated property keys. Each of these property keys is represented by an object which has the following attributes:

Attribute	Description
key	The key name of the duplicated property.
parent	The parent object of a property key.
occurrence	The number of property keys having the same key and parent object.

Moreover, these objects also contain the following functions for illustrating the actual path to the property key:

Function	Description
propertyPath()	Returns a list of property keys, which represents the path to the property key of the current object.
toString()	Prints the path to the property key. However, since all necessary raw data are also contained by the object, the result objects can also be represented in any other way if desired.

Note: When using find-duplicated-property-keys as a submodule, you always have to pass a JSON string instead of the file path to a JSON file.