JSON diff
npm install json-diffDoes exactly what you think it does:
``sh`
npm install -g json-diff
1. This project is maintained thanks to your contributions! Please send pull requests.
2. 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.
3. Anyone who gets a significant pull request merged gets commit access to the repository.
Simple:
`sh`
json-diff a.json b.json
Detailed:
`sh
% json-diff --help
Usage: json-diff [-vCjfonskKp] first.json second.json
Arguments:
General options:
-v, --verbose Output progress info
-C, --[no-]color Colored output
-j, --raw-json Display raw JSON encoding of the diff
-f, --full Include the equal sections of the document, not just the deltas
--max-elisions COUNT Max number of ...s to show in a row in "deltas" mode (before
collapsing them)
-o, --output-keys KEYS Always print this comma separated keys, with their value, if they are
part of an object with any diff
-x, --exclude-keys KEYS Exclude these comma separated keys from comparison on both files
-n, --output-new-only Output only the updated and new key/value pairs (without marking them as
such). If you need only the diffs from the old file, just exchange the
first and second json.
-s, --sort Sort primitive values in arrays before comparing
-k, --keys-only Compare only the keys, ignore the differences in values
-K, --keep-unchanged-values Instead of omitting values that are equal, output them as they are
-p, --precision DECIMALS Round all floating point numbers to this number of decimal places prior
to comparison
-h, --help Display this usage information
`
In javascript (ES5):
`js
var jsonDiff = require('json-diff');
console.log(jsonDiff.diffString({ foo: 'bar' }, { foo: 'baz' }));
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
// As above, but without console colors
console.log(jsonDiff.diffString({ foo: 'bar' }, { foo: 'baz' }, { color: false }));
// Raw output:
console.log(jsonDiff.diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }));
// Output:
// { foo: { __old: 'bar', __new: 'baz' } }
// Passing in the "full" option:
console.log(jsonDiff.diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }, { full: true }));
// Output:
// { foo: { __old: 'bar', __new: 'baz' }, b: 3 }
`
In javascript (ES6+):
`js
import { diffString, diff } from 'json-diff';
console.log(diffString({ foo: 'bar' }, { foo: 'baz' }));
console.log(diff({ foo: 'bar' }, { foo: 'baz' }));
`
- colorized, diff-like output
- fuzzy matching of modified array elements (when array elements are object hierarchies)
- "keysOnly" option to compare only the json structure (keys), ignoring the values
- "full" option to output the entire json tree, not just the deltas
- "outputKeys" option to always output the given keys for an object that has differences
- reasonable test coverage (far from 100%, though)
Unless two arrays are equal, all array elements are transformed into 2-tuple arrays:
- The first element is a one character string denoting the equality ('+', '-', '~', ' ')
- The second element is the old (-), new (+), altered sub-object (~), or unchanged (' ') value
`sh`
json-diff.js --full --raw-json <(echo '[1,7,3]') <(echo '[1,2,3]')
[ [ " ", 1 ], [ "-", 7 ], [ "+", 2 ], [ " ", 3 ] ]
`sh`
json-diff.js --full --raw-json <(echo '[1,["a","b"],4]') <(echo '[1,["a","c"],4]')
[ [ " ", 1 ], [ "~", [ [ " ", "a" ], [ "-", "b" ], [ "+", "c" ] ] ], [ " ", 4 ] ]
- If two arrays are equal, they are left as is.
Object property values:
- If equal, they are left as is
- Unequal scalar values are replaced by an object containing the old and new value:
`sh`
json-diff.js --full --raw-json <(echo '{"a":4}') <(echo '{"a":5}')
{ "a": { "__old": 4, "__new": 5 } }
- Unequal arrays and objects are replaced by their diff:
`sh`
json-diff.js --full --raw-json <(echo '{"a":[4,5]}') <(echo '{"a":[4,6]}')
{ "a": [ [ " ", 4 ], [ "-", 5 ], [ "+", 6 ] ] }
Object property keys:
- Object keys that are deleted or added between two objects are marked as such:
`sh`
json-diff.js --full --raw-json <(echo '{"a":[4,5]}') <(echo '{"b":[4,5]}')
{ "a__deleted": [ 4, 5 ], "b__added": [ 4, 5 ] }
json-diff.js --full --raw-json <(echo '{"a":[4,5]}') <(echo '{"b":[4,6]}')
{ "a__deleted": [ 4, 5 ], "b__added": [ 4, 6 ] }
- In regular, delta-only (non-"full") mode, equal properties and values are omitted:
`sh`
json-diff.js --raw-json <(echo '{"a":4, "b":6}') <(echo '{"a":5,"b":6}')
{ "a": { "__old": 4, "__new": 5 } }
- Equal array elements are represented by a one-tuple containing only a space " ":
`sh`
json-diff.js --raw-json <(echo '[1,7,3]') <(echo '[1,2,3]')
[ [ " " ], [ "-", 7 ], [ "+", 2 ], [ " " ] ]
Run:
`sh`
npm test
Output:
Open to View Test Output š½
json-diff@0.5.3 test
coffee -c test; mocha test/*.js
colorizeToArray
ā should return '
ā should return '
ā should return '
ā should return '-
ā should return '-
ā should return '-
ā should return '+
ā should return '+
ā should return '+
ā should return '+
ā should return '
ā should return '+
ā should return '-
ā should handle an array diff with subobject diff
ā should collapse long sequences of identical subobjects into one '...'
colorize
ā should return a string with ANSI escapes
ā should return a string without ANSI escapes on { color: false }
diff
with simple scalar values
ā should return undefined for two identical numbers
ā should return undefined for two identical strings
ā should return { __old:
with objects
ā should return undefined for two empty objects
ā should return undefined for two objects with identical contents
ā should return undefined for two object hierarchies with identical contents
ā should return {
ā should return {
ā should return {
ā should return {
with arrays of scalars
ā should return undefined for two arrays with identical contents
ā should return [..., ['-',
ā should return [..., ['+',
ā should return [..., ['+',
with arrays of objects
ā should return undefined for two arrays with identical contents
ā should return undefined for two arrays with identical, empty object contents
ā should return undefined for two arrays with identical, empty array contents
ā should return undefined for two arrays with identical array contents including 'null'
ā should return undefined for two arrays with identical, repeated contents
ā should return [..., ['-',
ā should return [..., ['+',
ā should return [['+',
ā should return [..., ['+',
ā should return [..., ['~',
with reported bugs
ā should handle type mismatch during scalarize
ā should handle mixed scalars and non-scalars in scalarize
diff({sort: true})
with arrays
ā should return undefined for two arrays with the same contents in different order
diff({keepUnchangedValues: true})
with nested object
ā should return partial object with modified and unmodified elements in the edited scope
diff({full: true})
with simple scalar values
ā should return the number for two identical numbers
ā should return the string for two identical strings
ā should return { __old:
with objects
ā should return an empty object for two empty objects
ā should return the object for two objects with identical contents
ā should return the object for two object hierarchies with identical contents
ā should return {
ā should return {
ā should return {
ā should return {
ā should return {
with arrays of scalars
ā should return an array showing no changes for any element for two arrays with identical contents
ā should return [[' ',
ā should return [' ',
ā should return [' ',
with arrays of objects
ā should return an array of unchanged elements for two arrays with identical contents
ā should return an array with an unchanged element for two arrays with identical, empty object contents
ā should return an array with an unchanged element for two arrays with identical, empty array contents
ā should return an array of unchanged elements for two arrays with identical array contents including 'null'
ā should return an array of unchanged elements for two arrays with identical, repeated contents
ā should return [[' ',
ā should return [[' ',
ā should return [[' ',
ā should return [[' ',
diff({ outputKeys: foo,bar }
ā should return keys foo and bar although they have no changes
ā should return keys foo (with addition) and bar (with no changes)
ā should return keys foo and bar (with addition)
ā should return nothing as the entire object is equal, no matter that show keys has some of them
ā should return the keys of an entire object although it has no changes
diff({keysOnly: true})
with simple scalar values
ā should return undefined for two identical numbers
ā should return undefined for two identical strings
ā should return undefined object for two different numbers
with objects
ā should return undefined for two empty objects
ā should return undefined for two objects with identical contents
ā should return undefined for two object hierarchies with identical contents
ā should return {
ā should return {
ā should return undefined for two objects with different scalar values for a key
ā should return undefined with a recursive diff for two objects with different values for a key
ā should return {
with arrays of scalars
ā should return undefined for two arrays with identical contents
ā should return undefined for two arrays with when an item has been modified
ā should return [..., ['-',
ā should return [..., ['+',
ā should return [..., ['+',
with arrays of objects
ā should return undefined for two arrays with identical contents
ā should return undefined for two arrays with identical, empty object contents
ā should return undefined for two arrays with identical, empty array contents
ā should return undefined for two arrays with identical, repeated contents
ā should return [..., ['-',
ā should return [..., ['+',
ā should return [..., ['~',
diffString
ā should produce the expected result for the example JSON files
ā should produce the expected result for the example JSON files with precision set to 1
ā should produce the expected colored result for the example JSON files
ā return an empty string when no diff found
diff({ outputNewOnly: true }
ā should return only new diffs (added)
ā should return only new diffs (changed)
ā should return only new diffs (deleted)
ā should return only old diffs - exchanged first and second json (added)
ā should return only old diffs - exchanged first and second json (changed)
ā should return only old diffs - exchanged first and second json (deleted)
107 passing (74ms)
vs [true], ["0"] vs [0]` (enabled by switching to a new difflib)Ā© Andrey Tarantsov. Distributed under the MIT license.