JSON similarity

Compute similarity of JSON objects with tests that yield points. Each test add or subtracts points. If total number of points becomes less than the treshold, the objects are deemed not similar. If all tests pass without the total number of points becoming less than the treshold, the objects are similar.

This program uses JSONPath implementation from dchester/jsonpath.

Usage

The module returns a single function which, when run, returns an object with the following properties:

• match (boolean): Whether the objects match or not
• points (number): Total number of points

AMD

define(['json-similarity'], function(jsonSimilarity) {
  console.log(jsonSimilarity(o1, o2, spec));
});

Node.js

var jsonSimilarity = require('json-similarity');

console.log(jsonSimilarity(o1, o2, spec));

Configuration

SEE resources/spec-schema.json FOR reference

Test spec is passed as a third argument to the similarity function. The object has the following properties:

treshold (number)

Number of points that is expected to be reached for the records to be deemed similar.

tests (array)

An array of tests to be run. Each test is an object which can have the following properties:

• true (number): Number of points to be added if the test succeeds (If omitted the points are added only if the test fails). Use a negative number for subtraction.
• false (number): Number of points to be added if the test fails (If omitted the points are added only if the test succeeds). Use a negative number for subtraction.
• path (string): Mandatory The path to test for. Path follows the JSONPath specification.
• options (object): Options can have the following properties:
  • trim (object): Operates on strings and numbers
    • chars (string): Characters to trim
    • side (number): If 0, trim from beginning of the property. If 1, trim from the end. If undefined, trim from both ends
  • truncate (number): Number of characters to truncate the target property to. Posite values truncate from the beginning, negative from the end. Operates on strings and numbers;
  • strict (boolean): Compare properties with strict equality (===)
  • order (boolean): Require elements to be in the same order when comparing array properties
  • caseSensitive (boolean): Compare string values case-sensitively (Defaults to true)

Examples

TODO

License and copyright

Copyright (c) 2015-2017 University Of Helsinki (The National Library Of Finland)

This project's source code is licensed under the terms of GNU General Public License Version 3.