SystemTextJson.JsonDiffPatch

High-performance, low-allocating JSON object diff and patch extension for System.Text.Json.

Features

• Compatible with jsondiffpatch delta format
• Support generating patch document in RFC 6902 JSON Patch format
• Target latest .NET Standard and .NET Framework 4.6.1 (for legacy apps) and leverage latest .NET features
• Alternative to jsondiffpatch.net which is based on Newtonsoft.Json
• Fast large JSON document diffing with less memory consumption (see benchmark)
• Support smart array diffing (e.g. move detect) using LCS (Longest Common Subsequence) and custom array item matcher
• (Only when not using RFC 6902 format) Support diffing long text using google-diff-match-patch, or write your own diff algorithm
• Bonus DeepEquals method for comparing JsonDocument, JsonElement and JsonNode
• Bonus DeepClone method
• Bonus JsonValueComparer that implements semantic comparison of two JsonValue objects
• JSON assert for xUnit, MSTest v2 and NUnit with customizable delta output

Install

JsonDiffPatch

PM> Install-Package SystemTextJson.JsonDiffPatch

xUnit Assert

PM> Install-Package SystemTextJson.JsonDiffPatch.Xunit

MSTest v2 Assert

PM> Install-Package SystemTextJson.JsonDiffPatch.MSTest

NUnit Assert

PM> Install-Package SystemTextJson.JsonDiffPatch.NUnit

Usage

Diff

// Diff JsonNode
var node1 = JsonNode.Parse("{\"foo\":\"bar\"}");
var node2 = JsonNode.Parse("{\"baz\":\"qux\", \"foo\":\"bar\"}");
var diff = node1.Diff(node2);
// Diff with options
var diff = node1.Diff(node2, new JsonDiffOptions
{
    JsonElementComparison = JsonElementComparison.Semantic
});
// Diff and convert delta into RFC 6902 JSON Patch format
var diff = node1.Diff(node2, new JsonPatchDeltaFormatter());
// Diff JSON files
var diff = JsonDiffPatcher.DiffFile(file1, file2);
// Diff Span<byte>
var diff = JsonDiffPatcher.Diff(span1, span2);
// Diff streams
var diff = JsonDiffPatcher.Diff(stream1, stream2);
// Diff JSON strings
var diff = JsonDiffPatcher.Diff(json1, json2);
// Diff JSON readers
var diff = JsonDiffPatcher.Diff(ref reader1, ref reader2);

Patch & Unpatch

var node1 = JsonNode.Parse("{\"foo\":\"bar\"}");
var node2 = JsonNode.Parse("{\"baz\":\"qux\", \"foo\":\"bar\"}");
var diff = node1.Diff(node2);
// In-place patch
JsonDiffPatcher.Patch(ref node1, diff);
// Clone & patch
var patched = node1.PatchNew(diff);
// In-place unpatch
JsonDiffPatcher.ReversePatch(ref node1, diff);
// Clone & unpatch
var patched = node1.ReversePatchNew(diff);

DeepEquals

// JsonDocument
var doc1 = JsonDocument.Parse("{\"foo\":1}");
var doc2 = JsonDocument.Parse("{\"foo\":1.0}");
var equal = doc1.DeepEquals(doc2);
var textEqual = doc1.DeepEquals(doc2, JsonElementComparison.RawText);
var semanticEqual = doc1.DeepEquals(doc2, JsonElementComparison.Semantic);

// JsonNode
var node1 = JsonNode.Parse("{\"foo\":1}");
var node2 = JsonNode.Parse("{\"foo\":1.0}");
var equal = node1.DeepEquals(node2);
var textEqual = node1.DeepEquals(node2, JsonElementComparison.RawText);
var semanticEqual = node1.DeepEquals(node2, JsonElementComparison.Semantic);

DeepClone

var node = JsonNode.Parse("{\"foo\":\"bar\"}");
var cloned = node.DeepClone();

Default Options

// Default diff options
JsonDiffPatcher.DefaultOptions = () => new JsonDiffOptions
{
    JsonElementComparison = JsonElementComparison.Semantic
};

// Default comparison mode for DeepEquals
JsonDiffPatcher.DefaultComparison = JsonElementComparison.Semantic;

Semantic Value Comparison

var node1 = JsonNode.Parse("\"2019-11-27\"");
var node2 = JsonNode.Parse("\"2019-11-27T00:00:00.000\"");
// dateCompare is 0
var dateCompare = JsonValueComparer.Compare(node1, node2);

var node3 = JsonNode.Parse("1");
var node4 = JsonNode.Parse("1.00");
// numCompare is 0
var numCompare = JsonValueComparer.Compare(node3, node4);

Assert (Unit Testing)

var expected = JsonNode.Parse("{\"foo\":\"bar\"}");
var actual = JsonNode.Parse("{\"baz\":\"qux\", \"foo\":\"bar3\"}");

// xUnit
JsonAssert.Equal(expected, actual);
actual.ShouldEqual(expected);
JsonAssert.NotEqual(expected, actual);
actual.ShouldNotEqual(expected);

// MSTest
JsonAssert.AreEqual(expected, actual);
Assert.That.JsonAreEqual(expected, actual);
JsonAssert.AreNotEqual(expected, actual);
Assert.That.JsonAreNotEqual(expected, actual);

// NUnit
JsonAssert.AreEqual(expected, actual);
Assert.That(actual, JsonIs.EqualTo(expected));
JsonAssert.AreNotEqual(expected, actual);
Assert.That(actual, JsonIs.NotEqualTo(expected));

Example output (when output is enabled):

JsonAssert.Equal() failure.
Expected:
{
  "foo": "bar"
}
Actual:
{
  "baz": "qux",
  "foo": "bar"
}
Delta:
{
  "foo": [
    "bar",
    "bar3"
  ],
  "baz": [
    "qux"
  ]
}

Benchmark

See detailed benchmark results.