PQSoft.JsonComparer 1.0.0-beta.2

PQSoft.JsonComparer

A powerful library for comparing JSON documents with advanced features.

Features

• Exact Match: Validates that two JSON documents are identical (except for tokens)
• Subset Match: Verifies that all elements in the expected JSON exist within the actual JSON
• Token Support: Extract values from actual JSON using tokens like [[TOKEN_NAME]]
• Function Execution: Execute functions like {{GUID()}}, {{NOW()}}, and {{UTCNOW()}} during comparison
• Variable Substitution: Substitute variables from provided context during preprocessing
• Detailed Mismatch Reporting: Provides structured information on any differences found
• Custom Function Registration: Extend functionality with custom functions

Installation

dotnet add package PQSoft.JsonComparer

Usage

Basic Exact Match

string expectedJson = """{ "id": "[[JOBID]]", "createdAt": "{{NOW()}}", "status": "complete" }""";
string actualJson = """{ "id": "12345", "createdAt": "2024-01-01T10:00:00.000+00:00", "status": "complete" }""";

bool isMatch = JsonComparer.ExactMatch(expectedJson, actualJson, out var extractedValues, out var mismatches);
// isMatch = true
// extractedValues["JOBID"] = "12345"

Subset Matching

string expectedSubset = """{ "status": "active", "type": "premium" }""";
string actualJson = """{ "id": 123, "name": "John", "status": "active", "type": "premium", "created": "2024-01-01" }""";

bool isSubset = JsonComparer.SubsetMatch(expectedSubset, actualJson, out var tokens, out var errors);
// isSubset = true - all expected fields exist in actual JSON

Token Extraction

string template = """{ "userId": "[[USER_ID]]", "orderId": "[[ORDER_ID]]", "total": "[[AMOUNT]]" }""";
string response = """{ "userId": "user_123", "orderId": "order_456", "total": "99.99" }""";

JsonComparer.ExactMatch(template, response, out var tokens, out var mismatches);
// tokens["USER_ID"] = "user_123"
// tokens["ORDER_ID"] = "order_456"
// tokens["AMOUNT"] = "99.99"

Function Execution

string template = """{
    "id": "{{GUID()}}",
    "timestamp": "{{UTCNOW()}}",
    "date": "{{NOW()}}"
}""";
string actual = """{
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2024-01-01T10:00:00.000Z",
    "date": "2024-01-01T10:00:00.000+00:00"
}""";

bool matches = JsonComparer.ExactMatch(template, actual, out var values, out var errors);
// Functions are executed and compared against actual values

Variable Substitution

var variables = new Dictionary<string, object>
{
    ["BASE_URL"] = "https://api.example.com",
    ["API_VERSION"] = "v1",
    ["USER_ID"] = 12345
};

string expectedJson = """{
    "endpoint": "{{BASE_URL}}/{{API_VERSION}}/users/{{USER_ID}}",
    "userId": {{USER_ID}}
}""";

string actualJson = """{
    "endpoint": "https://api.example.com/v1/users/12345",
    "userId": 12345
}"""

// Variables are substituted before comparison
bool matches = JsonComparer.ExactMatch(expectedJson, actualJson, variables, out var tokens, out var mismatches);

Custom Functions

// Register custom function
JsonComparer.RegisterFunction("CUSTOM_DATE", () => DateTime.Now.ToString("yyyy-MM-dd"));

string template = """{ "processedDate": "{{CUSTOM_DATE()}}" }""";
string actual = """{ "processedDate": "2024-01-01" }""";

bool matches = JsonComparer.ExactMatch(template, actual, out var tokens, out var errors);

Error Handling

string expected = """{ "name": "John", "age": 30 }""";
string actual = """{ "name": "Jane", "age": 25 }""";

bool matches = JsonComparer.ExactMatch(expected, actual, out var tokens, out var mismatches);

if (!matches)
{
    foreach (var mismatch in mismatches)
    {
        Console.WriteLine($"Path: {mismatch.Path}");
        Console.WriteLine($"Expected: {mismatch.Expected}");
        Console.WriteLine($"Actual: {mismatch.Actual}");
    }
}