Package Exports

json-diff
json-diff/lib/cli
json-diff/lib/colorize

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (json-diff) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

JSON structural diff

Does exactly what you think it does:

Screenshot

Installation

npm install json-diff

Contribution policy

This project is maintained thanks to your contributions! Please send pull requests.
I will merge any pull request that adds something useful, does not break existing things, has reasonable code quality and provides/updates tests where appropriate.
Anyone who gets a significant pull request merged gets commit access to the repository.

Usage

Simple:

json-diff a.json b.json

Detailed:

% json-diff --help
Usage: json-diff [-vjCk] first.json second.json

Arguments:
  first.json            Old file
  second.json           New file

General options:
  -v, --verbose         Output progress info
  -C, --[no-]color      Colored output
  -j, --raw-json        Display raw JSON encoding of the diff
  -k, --keys-only       Compare only the keys, ignore the differences in values
  -h, --help            Display this usage information

Programmatic:

Features

colorized, diff-like output
fuzzy matching of modified array elements (when array elements are object hierarchies)
compare only the json structure (keys), ignoring the values
reasonable test coverage (far from 100%, though)

Tests

Run:

npm test

Test coverage report:

npm run-script cov

Output:

colorize
  ✓ should return ' <value>' for a scalar value
  ✓ should return '-<old value>', '+<new value>' for a scalar diff
  ✓ should return '-<removed key>: <removed value>' for an object diff with a removed key
  ✓ should return '+<added key>: <added value>' for an object diff with an added key
  ✓ should return '+<added key>: <added stringified value>' for an object diff with an added key and a non-scalar value
  ✓ should return ' <modified key>: <colorized diff>' for an object diff with a modified key
  ✓ should return '+<inserted item>' for an array diff
  ✓ should return '-<deleted item>' for an array diff

diff
  with simple scalar values
    ✓ should return undefined for two identical numbers
    ✓ should return undefined for two identical strings
    ✓ should return { __old: <old value>, __new: <new value> } object for two different numbers
  with objects
    ✓ should return undefined for two objects with identical contents
    ✓ should return undefined for two object hierarchies with identical contents
    ✓ should return { <key>__deleted: <old value> } when the second object is missing a key
    ✓ should return { <key>__added: <new value> } when the first object is missing a key
    ✓ should return { <key>: { __old: <old value>, __new: <new value> } } for two objects with diffent scalar values for a key
    ✓ should return { <key>: <diff> } with a recursive diff for two objects with diffent values for a key
  with arrays of scalars
    ✓ should return undefined for two arrays with identical contents
    ✓ should return [..., ['-', <removed item>], ...] for two arrays when the second array is missing a value
    ✓ should return [..., ['+', <added item>], ...] for two arrays when the second one has an extra value
    ✓ should return [..., ['+', <added item>]] for two arrays when the second one has an extra value at the end (edge case test)
  with arrays of objects
    ✓ should return undefined for two arrays with identical contents
    ✓ should return [..., ['-', <removed item>], ...] for two arrays when the second array is missing a value
    ✓ should return [..., ['+', <added item>], ...] for two arrays when the second array has an extra value
    ✓ should return [..., ['~', <diff>], ...] for two arrays when an item has been modified (note: involves a crazy heuristic)

✔ 25 tests complete (12ms)

json-diff